EXTANT SEED PLANTS

Plant woody, evergreen; nicotinic acid metabolised to trigonelline; lignins rich in guaiacyl units; true roots present, xylem exarch, cork cambium deep seated; shoot apical meristem complex; stem with ectophloic eustele, endodermis 0, xylem endarch; vascular tissue in t.s. discontinuous by interfascicular regions; vascular cambium + [xylem ("wood") differentiating internally, phloem externally]; wood homoxylous, tracheids +; tracheid/tracheid pits circular, bordered; sieve tube/cell plastids with starch grains; phloem fibers +; cork cambium superficial; nodes ?; leaf vascular bundles collateral; leaves spiral, simple, axillary buds?, prophylls [including bracteoles] two, lateral; plant heterosporous, sporangia eusporangiate, on sporophylls, sporophylls aggregated; true pollen [microspores] +, mono[ana]sulcate, pollen exine and intine homogeneous, ovules unitegmic, crassinucellate, megaspore tetrad tetrahedral, only one megaspore develops, megasporangium indehiscent; male gametophyte development endo/exosporic, gametes two, with cell walls; female gametophyte endosporic, initially syncytial, walls then surrounding individual nuclei; seeds "large", first cell wall of zygote transverse, embryo straight, endoscopic [suspensor +], short-minute, with morphological dormancy, white, cotyledons 2; plastid transmission maternal; two copies of LEAFY gene, PHY gene duplication, mitochondrial nad1 intron 2 and coxIIi3 intron present.

MAGNOLIOPHYTA

Plant woody, evergreen; lignans, O-methyl flavonols, dihydroflavonols, triterpenoid oleanane, non-hydrolysable tannins, quercetin and/or kaempferol +, apigenin and/or luteolin scattered, cyanogenesis via tyrosine pathway, lignins derived from both coniferyl and sinapyl alcohols, containing syringaldehyde [in positive Maüle reaction, syringyl:guaiacyl ratio less than 2-2.5:1], and hemicelluloses as xyloglucans; root apical meristem intermediate-open; root vascular tissue oligarch [di- to pentarch], lateral roots arise opposite or immediately to the side of [when diarch] xylem poles; origin of epidermis with no clear pattern [probably from inner layer of root cap], trichoblasts [differentiated root hair-forming cells] 0; stem with 2-layered tunica-corpus construction; wood fibers and wood parenchyma +; reaction wood ?, with gelatinous fibres; starch grains simple; primary cell wall mostly with pectic polysaccharides; tracheids +; sieve tubes eunucleate, with sieve plate, companion cells from same mother cell that gave rise to the sieve tube; P-proteins in the sieve tube; nodes unilacunar; stomata with ends of guard cells level with aperture, paracytic; leaves with petiole and lamina [the latter formed from the primordial leaf apex], development of venation acropetal, 2ndary veins pinnate, fine venation reticulate, vein endings free; flowers perfect, polysymmetric, parts spiral [esp. the A], free, numbers unstable, P not differentiated, outer members not enclosing the rest of the bud, A many, development centripetal, with a single trace, introrse, filaments stout, anther ± embedded in the filament, tetrasporangiate, dithecal, with at least outer secondary parietal cells dividing, each theca dehiscing longitudinally by action of hypodermal endothecium, endothecial cells elongated at right angles to long axis of anther, tapetum glandular, binucleate, microsporogenesis successive, pollen subspherical, binucleate at dispersal, trinucleate eventually, tectum continuous, endexine compact, lamellate only in the apertural regions, pollen tube elongated, siphonogamy, nectary 0, G free, several, ascidiate, with postgenital occlusion by secretion, ovules marginal, anatropous, bitegmic, micropyle endostomal, integuments 2-3 cells thick, megasporocyte single, megaspore lacking sporopollenin and cuticle, chalazal, female gametophyte ?type, stylodium short, stigma ± decurrent, wet [secretory]; P deciduous in fruit; seed exotestal; double fertilisation +, endosperm ?diploid, cellular [first division oblique, micropylar end initially with a single large cell, chalazal end more actively dividing], copious, oily and/or proteinaceous, embryo cellular ab initio; germination hypogeal, seedlings/young plants sympodial; Arabidopsis-type telomeres [(TTTAGGG)_n]; whole genome duplication, single copy of LEAFY and RPB2 gene, knox genes extensively duplicated [A1-A4], AP1/FUL gene, paleo AP3 and PI genes [paralogous B-class genes] +, with "DEAER" motif, SEP3/LOFSEP and PHYA/PHYC gene pairs.

Possible apomorphies are in bold. Note that the actual level to which many of these features, particularly the more cryptic ones, should be assigned is unclear, because some taxa basal to the [magnoliid + monocot + eudicot] group have been surprisingly little studied. Furthermore, details of relationships among gymnosperms will affect the level at which some of these characters are pegged.

NYMPHAEALES [AUSTROBAILEYALES [CERATOPHYLLALES + CHLORANTHALES + MAGNOLIIDS [MONOCOTS + EUDICOTS]]: vessels +, elements with scalariform perforation plates; pollen tectate-columellate, tectum reticulate [perforated]; nucleus of egg cell sister to one of the polar nuclei; ?genome duplication; "DEAER" motif in AP3 and PI genes lost, gaps in these genes.

PROTEALES + TROCHODENDRALES + BUXALES + GUNNERALES + CORE EUDICOTS: ?

TROCHODENDRALES + BUXALES + GUNNERALES + CORE EUDICOTS: benzylisoquinoline alkaloids 0; euAP3 + TM6 genes [duplication of paleoAP3 gene: B class], mitochondrial rps2 gene lost.

BUXALES + GUNNERALES + CORE EUDICOTS: ?

GUNNERALES + CORE EUDICOTS: Ellagic and gallic acids common, cyanogenesis via phenylalanine, isoleucine or valine pathways; micropyle?; PI-dB motif +, small deletion in the 18S ribosomal DNA common.

CORE EUDICOTS: Root apical meristem closed; flowers rather stereotyped: 5-merous, K and C distinct, K with 3 traces, A = 2x K, internal to the C whorl, (numerous, but then often fasciculate and/or centrifugal), pollen tricolporate, (nectary disc +), [G 5], [3] also common, compitum +, placentation axile, stigma not decurrent; endosperm nuclear; fruit dry, dehiscent, loculicidal [when a capsule]; euAP1 + euFUL + AGL79 genes [duplication of AP1/FUL or FUL-like gene], PLE + euAG [duplication of AG-like gene: C class], SEP1 + FBP6 genes [duplication of AGL2/3/4 gene].

SAXIFRAGALES + VITALES + ROSIDS: Stipules +.

VITALES + ROSIDS: Anthers articulated [± dorsifixed, transition to filament narrow, connective thin].

ROSIDS: (nectary receptacular); embryo long; genome duplication; chloroplast infA gene defunct, mitochondrial coxII.i3 intron 0.

EUROSID II: Flavonols +; (cambium storied); petiole bundle(s) annular; style +.

Brassicales + Sapindales + Malvales: endosperm scanty.

BRASSICALES Bromhead  Main Tree, Synapomorphies.

Idioblastic and stomatal myrosin cells +, glucosinolates from phenyalanine and/or tyrosine, little oxalate accumulation; endoplasmic reticulum with dilated cisternae; myricetin and other methylated flavonols, tannins 0; vasicentric axial parenchyma +; tension wood?; leaves spiral, stipules small, cauline; inflorescence racemose; (petals clawed), G [3], ovules in one or two rows; seed coat?; embryo often green. - 17 families, 398 genera, 4450 species.

Brassicales contain ca 2.2% eudicot diversity (Magallön et al. 1999); the earliest fossil known is from the Turonian, ca 89.5 mybp; the stem group age is estimated to be 90-85 mybp, crown group age 71-69 mybp (Tropaeolum, etc., not included: Wikström et al. 2001). Caterpillars of Pieridae-Pierinae (ca 360 species, in 33+ genera; ca 1/3 of all records) are commonly found on members of this order (Fraenkel 1959; Ehrlich & Raven 1964; Braby & Trueman 2006), including Bretschneidera; they are abundant only in the Capparaceae-Cleomaceae-Brassicaceae clade. Pierinae may have moved to Brassicales from an original host in Fabaceae (Braby & Trueman 2006). Some chrysomelid beetles favor this clade, for example, Phyllotreta (Alticinae - see Jolivet & Hawkeswood 1995), while the dipteran leaf miner Liriomyza brassicae is found on Resedaceae, Cleomaceae, Tropaeolaceae and Brassicaceae (Spencer 1990).

A report of ellagic acid in "Capparidaceae" (Bate-Smith 1962) needs to be confirmed; Zindler-Frank (1976) lists seven families scattered throughout the order as having little oxalate accumulation. Many taxa seem to have diarch roots, although not some Cleomaceae; sampling in the basal pectinations is poor. Note that most families have stipules, albeit small. Strongly developed and fused ventral carpellary bundles may be another synapomorphy for the order (Ronse de Craene & Haston 2006).

Nearly all the glucosinolate-producing families of flowering plants are in this clade (c.f. Kjær 1974; Dahlgren 1975); for unrelated glucosinolate-containing families, see Putranjivaceae (Malpighiales) and perhaps also - but probably not - Phytolaccaceae (Caryophyllales) and Pittosporaceae (Apiales: Fahey et al. 2001 for a summary). It has also been suggested that Oceanopapaver, a genus of uncertain affinities but now pretty firmly associated with Malvaceae (Corchorus), has myrosin cells; this is unlikely (Whitlock et al. 2003). Specialised, protein-rich myrosin cells contain enzymes like thioglucoside glucohydrolase (a ß-thioglucohydrolase, or myrosinase), that that breaks down glucosinolates into glucose and isothiocyanates, thiocyanates (mustard oils - R-N=C=S arrangement), nitriles (not necessarily toxic) and other compounds when plant tissue is damaged by a herbivore (the "mustard oil bomb": see Rask et al. 2000, Wittstock et al. 2003, and Grubb & Abel 2006 for details, most of which have been worked out in Brassicaceae; Bones & Rossiter 2006 particularly for glucosinolate degradation), although not all taxa producing mustard oils have myrosin cells. Glucosinolates themselves are synthesised from valine/isoleucine and/or leucine in several families, but not in families in the terminal polychotomy (Rodman 1991a, for data) - could this be another synapomorphy for the order?

Relationships within Brassicales show a fair bit of structure (see tree), as Rodman et al. (1997, 1998), Carol et al. (1999), Chandler and Bayer (2000), Kubitzki (2002a), Olson (2002) and Hall et al. (2004) have found. Ronse de Craene and Haston (2006) examine morphological evolution in the clade in the context of a combined molecular (four genes, but some taxa included in the analysis lacking up to three of them) and morphological study; it is unclear what significance to attach to differences in details of the topology of the tree presented there and that used here. Analysis of morphological data alone yielded only one clade (Polanisia + Cleome!) in Brassicales with even weak support, and Bretschneidera and Akania were associated with Sapindaceae (Ronse de Craene & Haston 2006). However, that paper should be consulted for details of floral anatomical/morphological evolution in Brassicales. For the relationships of Emblingiaceae, sometimes associated with Gentianales, see below.

For general information, see Villers (1973), Mehta and Moseley (1981), Jørgensen (1981, 1995), Carlquist (1985a), Tobe and Peng (1990), Fisch and Weberling (1990), Rodman (1991a, b), Link (1992a), Rodman et al. (1993, 1994), Tobe and Takahashi (1995), Hufford (1996), Doweld (1996a, b), Ronse Decraene and Smets (1997) and Kubitzki (2002a, b: as Capparales).

Many Brassicalean families are included in Violanae (Dilleniidae) by Takhtajan (1997), but Gyrostemonales are in Gyrostemonanae (Caryophyllidae) and Limnanthales in Solananae (Lamiidae).

Includes Akaniaceae, Bataceae, Brassicaceae, Capparaceae, Caricaceae, Cleomaceae, Emblingiaceae, Gyrostemonaceae, Koeberliniaceae, Limnanthaceae, Moringaceae, Pentadiplandraceae, Resedaceae, Salvadoraceae, Setchellanthaceae, Stixaceae, Tovariaceae, Tropaeolaceae.

Synonymy: Akaniales Doweld, Batales Engler, Capparales Huchinson, Caricales L. D. Benson, Gyrostemonales Takhtajan, Limnanthales Nakai, Moringales Nakai, Resedales Dumortier, Salvadorales Reveal, Tovariales Nakai, Tropaeolales Reveal - Capparanae Reveal, Gyrostemonanae Takhtajan

Akaniaceae + Tropaeolaceae: vessel elements with scalariform perforations; axial parenchyma sparse, adjacent to vessels; bracteoles 0; flowers quite large, obliquely monosymmetric, hypanthium + ["between androecium and petals" - Ronse Decraene et al. 2002, but also true hypanthium in Bretschneidera, at least], C clawed, A 8, with short connective prolongations, placentation apical-axile, 1-2 epitropous ovules/carpel, style long.

It is possible that Tropaeolaceae have basically pinnate leaves (Endress 2003c), a matter than can be cleared up by further developmental studies. This may yield another synapomorphy for the clade. Although both families have a nectary, it is extrastaminal in Tropaeolaceae and intrastaminal in Akaniaceae. Furthermore, exactly which stamens are reduced and details of the plane of asymmetry of the flowers differ between Tropaeolum and Bretschneidera (Ronse Decraene et al. 2002a). Carlquist and Donald (1996) give additional characters of wood anatomy that unite these two families.

AKANIACEAE Stapf, nom. cons.   Back to Brassicales

Deciduous or evergreen trees; tannins?; cork subepidermal; young stem with separate bundles; (vessel elements with simple perforations); no bordered pits in imperforate tracheary elements; petiole bundle?; cuticle waxes 0, strong cuticular cracks; stomata ?; leaves odd-pinnate, leaflets spinulose-toothed or entire, supervolute-curved, petiolules swollen or articulated; (inflorescence branched); K ± connate, C contorted or not, A 8, or 3 (4) abaxial in the whorl opposite C [Akania], pollen colpate, disc + or 0, 2 apical pendulous (campylotropous - Bretschneidera) ovules/carpel, micropyle bistomal, stigma small, 3-lobed; fruit a septicidal capsule; testa vascularised, multiplicative, exotestal cells palisade, thick-walled, mesotesta ± thick, cells thick-walled, endotesta thickened; endosperm development?, copious or not, embryo color?, cotyledons large; n = 9 [Bretschneidera].

2[list]/2. S.W. China, adjacent Vietnam, Formosa (Bretschneidera sinensis [Photo - Collection]), E. Australia (Akania bidwillii).

Separating Bretschneideraceae from Akaniaceae s.l. is optional in A.P.G. II, however, there seems nothing lost in combining them. Akania has endosperm and may lack myrosin cells, but wood of the two genera is almost identical. In Bretschneidera, the flowers are clearly strongly obliquely monosymmetric. For ovules, see Mauritzon (1936). I have seen neither fresh vegetative material of Bretschneidera nor flowers of Akania. Seedlings of Akania initially produce at least five simple leaves with pinnate venation.

A relationship with Sapindales has often been suggested (e.g. Carlquist 1997a), but in this case perhaps largely because Sabiaceae were included in the latter; an analysis of morphological data also suggested this position (Ronse de Craene & Haston 2006). Bretschneideraceae do look rather sapindaceous.

For general information, see Bayer and Appel (2002).

Synonymy: Bretschneideraceae Engler & Gilg, nom. cons. (glucosinolates also from valine/isoleucine and/or leucine; leaflets entire; A curved and held under one petal, disc +, embryo sac bisporic, 8-nucleate.)

TROPAEOLACEAE Berchtold & J. Presl, nom. cons.   Back to Brassicales

Fleshy vine with twining petioles; glucosinolates also from valine/isoleucine and/or leucine, erucic acid [fatty acid] +; cork deep seated? to more superficial; only idioblastic myrosin cells; stem with separate bundles; petiole bundles annular; pericyclic fibers 0; cuticle waxes tubular; leaves flat in bud, palmately lobed (palmate), peltate or not, toothed to entire, stipules small, in seedling only, to fringed, subfoliaceous and throughout the plant; flowers often axillary, (bracteoles +); adaxial K (3 connate) spurred, C 2 + 3 (2), clawed, A 8, pollen trinucleate, median carpel adaxial, 2 tenuinucellate ovules/carpel, micropyle endostomal, stylodia short, trifid in appearance, stigma dry; fruit a schizocarp (samara), mericarps drupaceous or nutlike, K deciduous; seed pachychalazal, coat undistinguished, part of mesotesta suberized; amyloid in cotyledons, suspensor haustoria penetrate micropyle; n = 12-15.

1/95. New World (Map: see Sparre & Andersson 1991). [Photos - Tropaeolum Flower, Tropaeolum Flower]

• Tropaeolaceae are rather fleshy vines with twining petioles. The broad leaf blades have palmate venation and may be palmately-lobed, palmate or peltate. The flowers are large, strongly monosymmetric, and have an adaxial calycine spur, five clawed petals, and eight stamens. The fruit is usually a three-lobed schizocarp, and each unit contains but a single seed.

There is only a single genus in the family (Andersson & Andersson 2000).

Carlquist and Donald (1996) report vague storying of the secondary phloem of the root. For an interpretation of the axillary flowers common in Tropaeolum, see Bayer and Appel (2002). The nectary ends up in the spur; it is outside the stamens (Ronse Decraene et al. 2002). The median carpel is actually slightly off the median (Eichler 1878; Ronse Decraene & Smets 2001); two antepetalous stamens are suppressed (Ronse Decraene et al. 2002). There are initially two ovules per carpel, but one does not develop very far. The developing seed has a suspensor haustorial system (Walker 1947).

[Moringaceae + Caricaceae] [Limnanthaceae [Setchellanthaceae [[Koeberliniaceae [Bataceae + Salvadoraceae]] [Emblingiaceae [Pentadiplandraceae [Gyrostemonaceae + Resedaceae] Tovariaceae [Cleomaceae [Capparaceae + Brassicaceae]]]]]]]: ?

Moringaceae + Caricaceae: woody, stems stout; endoplasmic reticulum-dependent vacuoles; cambium storied; nodes also multilacunar; cuticle wax platelets as rosettes; venation palmate, colleters on petiole/lamina, stipules as glands; inflorescences thyrses; flowers whitish, G opposite K, ovary longitudinally sulcate, placental strands opposite the ventral bundles +, placentation parietal, many ovules/carpel, outer integument 5-6 cells across, micropyle bistomal, style hollow; testa multiplicative, mesotesta ± lignified.

Ronse de Craene and Haston (2006) suggest that nodes are unilacunar in this clade; they are tri or multilacunar. The sulci in the ovary are in the interplacental position. Whether or not the thickened mesotesta of the two families is comparable needs to be confirmed, certainly there are substantial anatomical differences in the seed coat (Olson 2002a).

For general information and relationships in this clade, see Olson (2002a).

MORINGACEAE Martynov, nom. cons.   Back to Brassicales

Deciduous trees or shrubs (stem succulents); glucosinolates also from valine/isoleucine and/or leucine; hairs unicellular; schizogenous gum canals +; leaves odd-pinnate, 1- or 3-compound; flowers obliquely monosymmetric; hypanthium short (long), lined with nectary, K petaloid, median [abaxial] C usu. larger than others, A = and opposite C, declinate, monothecal, staminodes opposite K, gynophore +, G ([2-4]), micropyle zig-zag, endothelium +, style slender, stigma punctate; fruit a 3-angled capsule; seeds 3-angled, winged (not), testa vascularised, mesotesta thick, outer and inner parts with helical thickenings, middle part much thickened, tegmen thin, (multiplicative); n = 11, 14.

1[list]/12. India to Africa, Madagascar, Moringa oleifera is quite widely cultivated (Map: from Olson 2001). [Photo - Flower, Collection]

• Moringaceae are woody, often quite stout-stemmed shrubs or trees whose foliage often smells unpleasantly when crushed. They are recognisable by their spiral, deciduous, odd-pinnate, 1- to 3-compound leaves that have conspicuous glands at the articulations and at the base; often clearly obliquely monosymmetric and papilionoid flowers (the median petal is adaxial) with five stamens; and long, slender, tricarpellate, three-angled, capsular fruits.

Olson and Rosell (2006) suggest that heterochrony is involved in the evolution of the various life forms in the family; the bottle-tree growth form is probably plesiomorphic, the tuberous shrub growth form is probably derived. All species have rather fleshy roots/rootstock.

The seedlings have palmately compound or simple leaves with palmate venation (M. Olson, pers. comm.). Even although flowers of all species are slightly monosymmetric early in development (Olson 2002b), flowers at anthesis may be polysymmetric or strongly monosymmetric. When flowers are monosymmetric, they are borne with the median petal adaxial, and when they are polysymmetric the median petal is in the normal abaxial position (Olson 2003). Carpel orientation is in the plane of symmetry of the flower (Ronse Decraene et al. 1998).

Some general information is taken from Ernst (1963), who described the ovules as being apotropous. For wood anatomy, see Olson and Carlquist (2001), and for phylogeny, etc., see Olson (2000b) and the Moringa website (Olson, 1999); there are reports of vestured pits from the family (Jansen et al. 2001b). Kubitzki (2002d) summarises information on the family.

Synonymy: Hyperantheraceae Link

CARICACEAE Burnett, nom. cons.   Back to Brassicales

(Viny, but with stout tuber), usu. prickly; only stomatal myrosin cells; articulated laticifers +, anastomosing; leaves palmately-veined or strongly lobed (palmate), flat-curved to involute, glands on adaxial surface at base; plants di(mon)oecious, inflorescences axillary, cymose; staminate flower: K connate, small, C connate, contorted or valvate, A adnate to C, 10, of two lengths and whorled, or = and opposite K, connective often developed, nectary on pistillode; carpellate flowers: as above, but C often free, A 0, nectary 0, G [5], (placentation axile), styles ± separate, stigmas flabellate or almost petaloid (capitate), dry; fruit a berry; sarcotesta +, mucilaginous, mesotesta tanniniferous, with lignified ribs, endotesta crystalliferous (lignified), exotegmen fibrous [?sclereidal?]; embryo white; n = 9.

4(-6)[list]/34: Carica 23. Mostly tropical America (three genera in Mexico); Africa (Cylicomorpha only) (Map: from Badillo 1971). [Photo - Plant, Flower, Fruit]

• Caricaceae are stout-stemmed often prickly tree, rarely vines, with flowing, latex-like exudate and palmately-compound or -lobed leaves. The inflorescences are axillary, cymose, and the flowers - always imperfect - are moderate in size. The fruit is a berry and contains numerous seeds clearly borne on five parietal placentae and each surrounded by mucilage.

Jacaratia has carpellate flowers with white, spreading stigmas mimicking staminate flowers (Bawa 1980). Reports of cyclopentenoid cyanogenic glycosides in the family have been questioned (Jørgenson 1995).

Some general information is taken from Badillo (1971), Miller (1982) and Kubitzki (2002d); for embryology, see Singh (1970), wood anatomy, see Carlquist (1998c); for floral development, see Ronse Decraene and Smets (1998b), and for phylogeny, see Kyndt et al. (2005: Cyclimorpha sister to the rest of the family).

Setchellanthaceae [Limnanthaceae [[Koeberliniaceae [Bataceae + Salvadoraceae]] [Emblingiaceae [Pentadiplandraceae [Gyrostemonaceae + Resedaceae] Tovariaceae [Cleomaceae [Capparaceae + Brassicaceae]]]]]]: nodes 1:1.

SETCHELLANTHACEAE Iltis   Back to Brassicales

Shrub; hairs unicellular, T-shaped, on multicellular podium; myrosin cells 0; young stem with vascular cylinder; vestured pits 0; ?stomata; 2ndary veins subbasal, stipules 0; flowers axillary, large, (5)6(7)-merous; K connate, splitting irregularly, C clawed, A many, centrifugal, in 5-7 groups on elongated axis, pollen tricolpate, disc 0, gynophore short, placentation axile, 10-14 ovules/carpel in two ranks, style short, stigmas subcapitate; fruit a septifragal capsule, central columella persistent; testa soft, endosperm development?, scanty; n =?

1/1: Setchellanthus caeruleus. Mexico (Map: see Iltis 1999). [Photos - Flower, Flower, Fruit]

• Setchellanthaceae are pungent-smelling shrubs that may be recognised by their large, blue, axillary flowers with parts usually in sixes and an irregularly-splitting calyx. Vegetatively the plant is rather undistinguished, although it has T-shaped hairs and the rather small, entire, exstipulate leaves have secondary veins arising from near the base and lack much in the way of a petiole. The three-carpellate fruit is septifragal and there is a persistent columella.

Setchellanthus used to be included in Capparaceae (Brassicaceae-Capparoideae), but it comes out near Limnanthaceae in molecular phylogenies (Karol et al. 1999, see also Rodman et al. 1997), although just basal to them in Chandler and Bayer (2000).

The fusion of the marginal ventral bundles is commissural.

Some information is taken from Carlquist and Miller (1999: anatomy), Iltis (1999: general), Tobe et al. (1999: flowers), Tomb (1999: pollen), and Kubitzki (2002d: general).

Limnanthaceae [[Koeberliniaceae [Bataceae + Salvadoraceae]] [Emblingiaceae [Pentadiplandraceae [Gyrostemonaceae + Resedaceae] Tovariaceae [Cleomaceae [Capparaceae + Brassicaceae]]]]]: root hairs in vertical files.

Root trichoblasts have been sampled in rather few families. The distinctive vertical files of root hairs are known from Limnanthaceae and some terminal members of Brassicales, they have not been observed in Tropaeolaceae, but other taxa have not been studied (Dolan & Costa 2001).

LIMNANTHACEAE R. Brown, nom. cons.   Back to Brassicales

Herbs; erucic acid, ellagic acid, myricetin, leucoanthocyanins +, isokestose oligosaccharides as storage; cork?; only idioblastic myrosin cells; leave blades pinnate(ly lobed), conduplicate, margin with teeth, stipules 0; (flowers single, axillary, bracteoles 0); flowers 3-5-merous, K valvate, C contorted, A 2x K, of two lengths ( = and opposite K), pollen zonosulcate, nectaries on abaxial bases of antesepalous A (0), G [2-5], opposite K, when 3 median member abaxial, placentation basal-parietal, 1 apotropous tenuinucellate unitegmic ovule/carpel, embryo sac tetrasporic, 4- or 6-nucleate, style +/0, stylodia ± well developed, gynobasic, hollow, stigma punctate to minutely capitate, dry; fruit a schizocarp, mericarps muriculate, K persistent; seed coat pachychalazal, thick, with vascular bundles, otherwise undistinguished; amyloid in cotyledons, embryo color?, cotyledons cordate; n = 5.

1(2)[list]/8. Temperate North America (Map: from Culham 2007). [Photo - Flower] [Photo - Flower (close-up)]

• Limnanthaceae are rather soft-stemmed herbs with spiral, exstipulate, deeply-lobed or compound leaves and rather open flowers with a valvate calyx, contorted corolla, and gynobasic style or stylodia. The fruit is a schizocarp separating into shortly spiny, one-seeded portions (mericarps).

Limnanthaceae were often included in Geraniales, but the androecium is diplostemonous, that of Geraniaceae is obdiplostemonous, the ovules are apotropous, not epitropous, and carpel orientation differs (Eckert 1966). The ovules differ from those of other Brassicales, which are usuaully crassinucellate, bitegmic, and with a monosporic, 8-nucleate embryo sac (but see Akaniaceae), but chemistry and molecular data place them here.

According to van Tieghem (1898), the integument is very thick and the ovules are epitropous, while Johri (1970) described an endosperm pouch or haustorium on the funicular side of the micropyle region.

Limnanthaceae were placed in Solananae by Takhtajan (1997).

Some information is taken from Link (1992a) and that on wood anatomy from Carlquist and Donald (1996); for general information, see Bayer and Appel (2002).

[Koeberliniaceae [Bataceae + Salvadoraceae]] [Emblingiaceae [Pentadiplandraceae [Gyrostemonaceae + Resedaceae] Tovariaceae [Cleomaceae [Capparaceae + Brassicaceae]]]]: glucosinolates from chain-elongated branched-chain amino acids; style/stylodia short to absent; seeds exotegmic; embryo strongly curved.

Amino acids like isoleucine with branched chains may have additional carbons along the chain; the occurrence of such chain-elongated branched-chain amino acids is to be pegged here on the tree (J. E. Rodman, pers. comm.). There is extensive variation of floral meristicity in the Emblingiaceae-Brassicaceae group in particular, but 4-merous flowers could be an apomorphy at this level - but with plenty of reversals. A fibrous, if unlignified, exotegmen may well be another apomorphy; it has, for example, been reported from Koeberliniaceae, Salvadoraceae, Resedaceae, Cleomaceae, etc.

Koeberliniaceae [Bataceae + Salvadoraceae]: idioblastic myrosin cells 0; flowers 4-merous, pollen 3-colporoidate, disc 0, G [2]; fruit indehiscent; exotestal cells well developed; n = 11.

KOEBERLINIACEAE Engler, nom. cons.   Back to Brassicales

Woody, thorny; ellagic acid?, tannins?; no glucosinolates; cork pericyclic; perforation plates bordered; pits vestured; intercellular canals +; leaves minute, fugacious, stipules 0; inflorescences axillary, flowers (5)-merous, A 8 (10), nectaries at their base, tapetal cells multinucleate, G shortly stipitate, placentation axile, ca 10 anatropous apotropous and epitropous ovules/carpel, micropyle zig-zag, style +, stigma minutely expanded; fruit a berry; exotesta with massive cuticle, then tanniniferous cells, ?exotegmen walls very thick, lignified, cells moderately elongated; embryo green, endosperm type?, moderate, cotyledons incumbent.

1/1: Koeberlinia spinosa. C. and S.W. North America, Bolivia(!) (Map: from Vester 1940; 2007). [Photo - Habit] [Photo - Flower]

• Koeberliniaceae are thorny, much-branched shrubs of dry regions; the prophylls are basal on the branches/thorns. The flowers are small and undistinguished, and the fruit is a few(1-2)-seeded berry terminated by the persistent style.

The ovules look as if they may be campylotropous. Nodal anatomy is taken from that of the bracts (Mehta & Moseley 1981). Canotia, sometimes placed here (e.g. Hutchinson 1973), is included in Celastraceae.

For anatomy, see Gibson (1979), for floral anatomy, see Mehta and Moseley (1981), and for general information, see Kubitzki (2002d); von Schrenk, Aug. 8, Texas - seed anatomy.

Bataceae + Salvadoraceae: wood ± storied; perforation plates not bordered; rays wide, multiseriate; nodes 1:2; stomata paracytic; leaves opposite, with 2ndary veins ascending from at or near base; A 5 [alternating with K], pollen psilate, 2 basal ovules/carpel; endosperm 0, embryo ± straight, color?

The two families are very similar anatomically (Carlquist 2002a). Azima has two trace-one gap nodes to the bracts and bracteoles, Salvadora has one trace, one gap nodes to the bracts (Kshetrapal 1970). R. A. Howard (pers. comm.) reported two trace, one gap nodes from both genera. Ronse de Craene and Haston (2006) list a number of other features the two families share including colleter-like stipules, a sepal tube, endostomal micropyle, etc.

BATACEAE Perleb, nom. cons.   Back to Brassicales

Fleshy shrublets; (hydroxy)proline betaines +, tannins?; cork pericyclic; perforation plate borders vestigial; pits vestured; leaves fleshy, stipules unvascularised, intrapetiolar or cauline; plant monoecious or dioecious, inflorescences usually axillary, densely spicate; flowers small, bracteoles 0; staminate flowers: K 2, median, enveloping flower, or K 4, connate, P clawed, A = and alternate with P, pollen ektexine spongy, undifferentiated; carpellate flowers: P 0, G 4 locular [carpels subdivided], 2 collateral epitropous ovules/carpel, micropyle ± zig-zag, nucellar cap +, style/stylodium 0, stigmas capitate-penicillate; fruit multiple, or a drupe with four pyrenes; seed coat membranaceous.

1[list]/2. N. Australia and S. New Guinea, tropical America, and the Galapagos (introduced into the Hawaiian Is.) (Map: from van Steenis & van Balgooy 1966; Heywood 1978; George 1982). [Photo - Flowers]

• Bataceae are halophytic subshrubs with opposite, small, entire, fleshy leaves that have minute "stipules". The flowers are staminate or carpellate and aggregated into dense, spicate, more or less strobilate, inflorescences. The carpellate flowers lack bracts or perianth and are fused together to form a compound fruit.

For the nodal anatomy of Batis maritima, with what is presumably the foliar trace disappearing as it approaches the node, the leaf being supplied by two bundles from the angles of the stem, see van Tieghem (1893), but cf. Johnson (1935) and R. A. Howard (pers. comm.). The stipules need study: van Tieghem reports them to be absent, Johnson (1935) that they are between the broad leaf base and the stem, Rogers (1982b) that they are cauline, while Ronse De Craene (2005) in a floral study describes the fairly massive structures in this position in the flowers as being colleters (note that these are not mutually exclusive). The morphological nature of the structure enveloping the staminate flowers is most obvious in B. argillicola, but there is controversy over the nature of this structure, too; in Batis maritima, Ronse De Craene (2005) describes it as being derived from four sepals, although he noted that it had only a single vascular trace; some of the lobing of the tubular structure may in fact be caused by pressure from other parts of the developing flower rather than reflecting the inherently four-merous nature of the tube.

Batygina et al. (1985) provide information on the ovules, for pollen, see Tobe and Takahashi (1995), for floral development of Batis maritima, see Ronse De Craene (2005), and for general information, see Bayer and Appel (2002).

SALVADORACEAE Lindley, nom. cons.   Back to Brassicales

Woody; tannins 0; cisternae of endoplasmic reticulum dilated, but no myrosin cells; cork superficial; wood storied; included phloem +; cuticle waxes with platelets; leaf ptyxis flat-curved [Salvadora]; plant dioecious or polygamous, or flowers bisexual; K 2-4(-5), contorted, basally connate, C (5), contorted (connate), A = and opposite K, free, connate, or adnate to C, pollen?, nectar glands alternating with A or 0, G 1-2-locular, 1-2 apotropous ovules/carpel, micropyle various, (style +, short), stigma at most slightly lobed; fruit a berry or drupe; exotestal cells palisade, slightly thickened, inner walls mucilaginous, crystalliferous, tegmen becoming crushed, exotegmic cells fibrous, not lignified; cotyledons thick; n also = 12.

3[list]/11: Salvadora (5). Africa (inc. Madagascar) to South East Asia and West Malesia, often in drier regions (Map: from Aubréville 1974 - Malesian distribution rather optimistic, perhaps only in Java). [Photo - Habit, Fruits]

• Salvadoraceae are rather small-leaved shrubs, sometimes scrambling, or small treees with opposite, rather leathery leaves; small, 4-merous flowers with connate sepals and two carpels with a short style; and a fleshy fruit.

For wood anatomy, see Carlquist (2002a), for general information, see Kubitzki (2002d).

Synonymy: Azimaceae Wight & Gardner

Emblingiaceae [Pentadiplandraceae [Gyrostemonaceae + Resedaceae] Tovariaceae [Cleomaceae [Capparaceae + Brassicaceae]]]: glucosinolates also from valine/isoleucine and/or leucine, indole glucosinolates from tryptophan [Embl. + Gyro. unknown]; cisternae of endoplasmic reticulum dilated and vacuole-like; cuticle wax crystalloids 0; inflorescence terminal, racemose, bracteoles 0; floral development open, C clawed, disc/nectary outside A, ovules ± campylotropous, in two rows; endotesta crystalliferous, exotegmen fibrous; 3' rbcL extension.

In Pentadiplandraceae, Brassicaceae and Tovariaceae the lateral sepals are initiated before the median sepals (Ronse Decraene 2002). For ovule type and the different mechanisms by which the ovule becomes campylotropous, see Boesewinkel (1990) and Bouman and Boesewinkel (1991), for bracteoles, see Ronse Decraene (1992). Ronse de Craene and Haston (2006) suggest a number of other characters that may be synapomorphies for this clade, including floral symmetry and embryo development.

Phylogenetic relationships in this core group of Brassicales have been partly resolved in a three-gene study by Hall et al. (2004); Ronse de Craene and Haston (2006) find Emblingiaceae to move outside of this group in a combined morphological-molecular study, but many data were missing for Emblingia in particular.

EMBLINGIACEAE Airy Shaw   Back to Brassicales

Subshrub; plant hispid; mustard oils?; cork deep-seated; cambium storying?; sclereids +; leaves ± opposite; flowers axillary, monosymmetric, resupinate, K connate, lobed, deeply divided adaxially, C 2, ?not clawed, abaxial, connate by epidermis, slipper-shaped, nectary abaxial, androgynophore curved abaxially, A 8, median members absent, 4 abaxial fertile, 4 adaxial staminodial, forming a torus, pollen with short colpi with rounded ends and bulging apertures, the adjacent exine being thickened, G [2-3], placentation axile, 1 basal ovule/carpel, stigma shortly lobed; fruit indehiscent, pericarp thin; seed arillate, testa thick; endosperm ?type, scanty, embryo color?; n = ?

1[list]/1: Emblingia calceoliflora. W. Australia (Map: from FloraBase 2004).

• Emblingiaceae are low-growing herbs with axillary, ebracteolate and strongly monosymmetric flowers. The flowers are held upside down, the large, connate calyx is slit adaxially, there are two, abaxial, slipper-shaped petals (hence the specific epithet), and there is a curved androgynophore with an abaxially-positioned nectary at the base.

The plant dries yellowish. There has been considerable disagreement over the floral structure: is the flower resupinate or not? Is the hood petalline or not: Are there one or three carpels? I largely follow Melville's interpretation (in Erdtman et al. 1969), see also Mueller (1860). Detailed studies of all aspects of this plant are needed, nevertheless, its embryo is curved, its flowers monosymmetrical, and its nectary is between the petals and stamens, all features appropriate for a position around here.

Emblingia was included in Polygalaceae by Cronquist (1981) and Polygalales by Takhtajan (1997), but in Brassicales by A.P.G. (1998) and Chandler and Bayer (2000). Ronse de Craene and Haston (2006) suggest it may be sister to [Bataceae + Salvadoraceae], but noted that there was little support for this position. However, Savolainen et al. (2000b) placed it in Gentianales, a position that is not currently supported.

For general information, see Kubitzki (2002d).

Pentadiplandraceae [Gyrostemonaceae + Resedaceae] Tovariaceae [Cleomaceae [Capparaceae + Brassicaceae]]: ?

The larvae of Chrysomelidae-Alticinae beetles seem quite commonly to be found in this clade (Jolivet 1988). This is the core Brassicales of Ronse de Craene and Haston (2006).

PENTADIPLANDRACEAE Hutchinson & Dalziel   Back to Brassicales

Shrubs or lianes; ellagic acid?, tannins?; cork?; vessel elements with ? perforations; wood ?storied; nodes 3:3; mucilage cells +; stipules minute; inflorescence axillary, subcorymbose, flowers polygamous; K 5, valvate, C 5, connivent at enlarged, concave base, limb flat, short andogynophore/disc, staminate flowers: A 9-13, connective shortly produced, pistillode +; carpellate flowers: staminodes +, gynophore short, G [3-5], G opposite K, placentation axile, ca 10 ovules/carpel in two ranks, ovule type?, style long, stigma shortly lobed; fruit a berry; 1 seed/loculus, coat with layer of white, wooly, elongated cells towards outside ["seed pubescent"]; embryo white; n = ?

1/?1 (Pentadiplandra brazzeana). Tropical W. Africa (Map: from Hall et al. 2004).

The fruit contains the sweet-tasting protein, brazzein.

Embryologically - and in many other respects - Pentadiplandra is poorly known, although Ronse Decraene (2002) has described its floral anatomy; Ronse de Craene and Haston (2006) suggest that its floral morphology is close to the ancestral form of the core Brassicales. There are no marginal or placental strands in the ovary. Ronse Decraene (2002) also suggests that the stipules are large, but they are certainly not particularly big on the vegtative part of the plant. The plant does not dry dark. Are there supernumerary buds? There are bordered pits in wood fibres and mucilage cells in the leaf epidermis (Boodle, K, ms.).

For general information, see Bayer and Appel (2002), for embryo color, Martin Cheek (pers. comm.)

[Gyrostemonaceae + Resedaceae] Tovariaceae [Cleomaceae [Capparaceae + Brassicaceae]]: ?

The stem group age for this group is estimated to be 47-45 mybp, the crown group age 42-33 mybp (Wikström et al. 2001)

Nucellar tracheids have been reported in Capparaceae and Resedaceae, at least (Werker 1997). The wood anatomy of Brassicaceae and Resedaceae, at least, is rather similar (Schweingruber 2006). For stipules, see Weberling (2006).

Gyrostemonaceae + Resedaceae: hairs unicellular; stylodia +; calyx persistent; seeds arillate.

The composition of this clade and relationships within it are currently uncertain. Of the sampled Stixeae (ex Capparaceae) that come out around here, the Asian Tirania may be close to Gyrostemonaceae and the New World Forchhammeria may be closer to Resedaceae (Hall & Sytsma 2000; Hall et al. 2002), or both may be associated with Resedaceae (Hall et al. 2004: details of the relationship depend on the gene sequenced). Tirania has six sepals and petals and axile placentation. Forchhammeria has two carpels, as well as an irregular number of sepals (see Gyrostemonaceae!), no petals, parietal placentation and one ovule/carpel, only one one ovule/fruit usually developing. The whole Stixeae (= Stixaceae Doweld   Back to Brassicales) - and also Boscia - have successive cambia (Carlquist 1988) and are certainly out of place in Capparaceae (Map: from Jacobs 1960).

GYROSTEMONACEAE Endlicher, nom. cons.   Back to Brassicales

Trees to shrubs; myrosin cells 0, tannins?; cork subepidermal; wood storied; petiole bundle arcuate; leave blades flat in bud, (stipules 0); plants usu. dioecious, inflorescence various; flowers small, P uniseriate, connate, 4-8-lobed or not, axis flattened, disc-like; staminate flowers: A 6-many, in 1 or more whorls around axis, centripetal, filaments ± 0, pollen tricolpate, ektexine spongy, undifferentiated; carpellate flowers: G (1 [2-)many], borne around axis in 1 (2) whorls, connate or not, when G 2, transverse, placentation axile-apical, 1 apotropous ovule/carpel, stylodia + (marginal), stigmas decurrent, large and spreading or not; fruit a dry or succulent schizocarp (achene; syncarp); endosperm copious, embryo color?; n = 14.

5[list]/18+: Gyrostemon (12). Australia, not in the north (Map: see George 1982).

• Gyrostemonaceae are yellowish-drying (including the twigs!) shrubs with rather small, often quite narrow but otherwise featureless leaves. The rather small flowers with a persistent, connate calyx (presumably; there is only a single perianth whorl) and many stamens and/or carpels clearly arranged in a whorl are quite distinctive.

Gyrostemonaceae are wind-pollinated.

For gynoecial orientation, see Friedrich (1956), for pollen, see Tobe and Takahashi(1995), for additional information, see Goldblatt et al. (1976: general), Hufford (1996: floral development) and George (2002d: general).

RESEDACEAE Berchtold & J. Presl, nom. cons.   Back to Brassicales

Herbs (shrubby); stomatal myrosin cells only, tannins 0; cork?; no bordered pits in imperforate tracheary elements; leaf blade margins entire to pinnatifid, (stipules 0); flowers vertically monosymmetric, hypanthium short or 0, K ± valvate, (4-)6(-8), C valvate, (0, 2, 4-)6(-8), unequal, the adaxial largest, ligulate at junction of claw and limb, limb usu. ± fringed, disc esp. pronounced adaxially, (bipartite) petaloid, A 3-many and centrifugal, basally connate or not, (short gynophore +), G [(2) 3-6(-8)] (free), opposite K or when 3, median member often adaxial, often open apical-adaxially, placentation parietal (axile), (1-)several (tenuinucellate) ovules/carpel; fruit with apical opening persisting between the stylodia (follicle; berry); (aril 0), endotestal cells cuboid, ± thickened, unlignified, exotegmic cells fibrous, lignified; n = 6-15.

6[list]/75: Reseda (60). N. warm temperate and subtropical, esp. Mediterranean-Middle East-North African, also Africa, some S.W. North America (Map: see Meusel et al. 1965; Hultén & Fries 1986). [Photo - Flower]

• Resedaceae are yellowish-drying sometimes somewhat shrubby herbs with terminal, racemose inflorescences and rather small, monosymmetric flowers. The leaves are quite variable, although there are often small stipules. The petals are free and clawed; the adaxial petal is usually largest and the limb is often fringed. The extrastaminal disc/nectary is often conspicuous. The dry fruits often have an apical opening persisting between the stylodia (a quasi follicle) and the seeds are often arillate.

Ochradenus has C 0, A many, G 3, the carpels are ultimately closed, and the fruit is berry-like - cf. Gyrostemonaceae (Hufford 1996). The androecium of Reseda luteola may be in 3-4 whorls (for references, see Abdallah 1978), cf. again also Gyrostemonaceae. The appendages on the fruit are also described as being carunculate.

For stipules, see Weberling (1968), for general information, see Abdallah (1967), Abdallah and de Wit (1979) and Kubitzki (2002d), and for wood anatomy, see Carlquist (1998a) and Schweingruber (2006).

Synonymy: Astrocarpaceae A. Kerner

TOVARIACEAE Pax, nom. cons.   Back to Brassicales

Herbs to shrubs; glucosinolates not from phenylanaline or tyrosine, tannins?; cork?; no bordered pits in imperforate tracheary elements; leaves trifoliolate, stipules cauline or on leaf base; flowers (6-)8(-9)-merous, K free, A = and opposite K, gynophore short, G [(5) 6(-8)], alternating with K, placentation ± axile, many ovules/carpel in several ranks, micropyle zig-zag, funicle long, stigmas spreading; fruit a berry; exotestal cells ± enlarged, tanniniferous, walls thickened, endotestal cells small, exotegmic cells fibrous, walls reticulately thickened; endosperm thin, embryo color?; n = 14.

1[list]/2. Tropical America (Map: see Hall et al. 2004). [Photo - Flower, Fruit]

• Tovariaceae are herbs that can be recognised by their trifoliate, stipulate leaves, terminal, racemose inflorescence, and 6-9-merous, polypetalous flowers with a short style and spreading stigmas.

The ovules are ± anatropous, but become campylotropous by the post-fertilisation development of the exotegmen (Boesewinkel 1990).

For general information, see Appel and Bayer (2002).

Cleomaceae [Capparaceae + Brassicaceae]: sinapine, methyl glucosinolates, erucic acid [fatty acid] +, glucosinolates also from methionine; idioblastic myrosin cells only, cisternae of endoplasmic reticulum organelle-like, etc.; cork also cortical; lateral wall pits of vessels vestured; nodes also 3<:3<; eglandular hairs simple, unicellular [?level]; leaves simple to palmately compound, blades usu. conduplicate, margins pinnately lobed to entire; flowers 4-merous, (vertically monosymmetric); K (2-)4(-6), A from 4 primordia, centrifugal, longer than the petals, filaments articulated, gynophore +, when 2 carpels, collateral (superposed, oblique), placental strands well developed, placentation parietal, many (tenuinucellate) ovules/carpel, micropyle zig-zag (endostomal), stigma lobed, subcapitate or not; K deciduous; seeds with invaginated coat, exotesta palisade or not, endotesta with inner walls ± thickened, ± thick-walled, endotegmen lignified (or not).   Back to Brassicales

The divergence between Capparaceae and the [Cleomaceae + Brassicaceae] clade has been dated to ca 23 mybp (Wikström et al. 2001), but this is in conflict with other estimates for ages in this clade, e.g. divergence between Capparaceae and Brassicaceae at ca 41 mybp (Schranz & Mitchell-Olds 2006). Pierid caterpillars (Pieridae-Pierinae) are notably common on members of this group. For details of the interactions of butterflies and plants, see Courtney (1986) and Chew (1988) and references. Ca 1,000 species are susceptible to pseudoflower-forming rust fungi (Puccinia spp.: see Roy 1993 [particularly fine photograph], 2001). Insects come to the pseudoflowers, pick up the rich fructose nectar secreted by the fungus - along with the spermatia in the nectar. On combination of spermatia of the appropriate mating types, aecia are produced and the "flower" stops producing nectar and turns green.

Capparaceae are sister to Cleomaceae + Brassicaceae; for further details of relationships see Hall and Sytsma (2000) and Hall et al. (2002). Vaughan and Whitehouse (1971) suggest that Brassicaceae differ from Capparaceae (inc. Cleomaceae) in that the latter have a testa that is only two (not three) cell layers thick, a persistent tegmen (rare) and a thicker endosperm (1 cell layer thick). Judd et al. (1994) provide a morphological phylogeny for Brassicaceae and Capparaceae sensu latissimo.

Although Cruciferae/Brassicaceae s. str., cabbage and mustard, have always been considered one of the most natural plant families, their recognition makes Capparaceae s.l. (= Capparaceae s. str. + Cleomaceae) paraphyletic. So the alternatives are to have one family (Brassicaceae s.l.), three families, or two families, a Brassicaceae including Cleomoideae and a Capparaceae; the second option is followed here.

Campylotropy is by the inpushing of the chalazal bundle. True blue or red flowers are very rare in the whole group. The ventral carpellary bundles are fused and weakly developed (Ronse de Craene & Haston 2006).

The distribution of root hairs and of methyl glucosinolates, and variation patterns in seed coat anatomy are a little odd... Both Brassicaceae and Resedaceae have glucosinolates derived from elongated amino acid chains (Kjær 1973; esp. Fahey et al. 2001). Only Wasabia japonica in Brassicaceae has a glucosinolate similar to those in Cleomaceae and Capparaceae, while one aromatic glucosinolate of Cleomaceae and Capparaceae is also found in Resedaceae. Quaternary ammonium compunds, including betaines, are common in both Capparaceae and Cleomaceae, and also Boscia (see Resedaceae + Gyrostemonaceae), but have not been detected in Pentadiplandra or Emblingia - or Buhsia (McLean et al. 1996).

CAPPARACEAE Jussieu, nom. cons.   Back to Brassicales

Trees and shrubs (herbs); root hairs 0; pyrrolidine alkaloids +; petiole bundle annular or arcuate; sclereids +; (inflorescence fasciculate); (flowers monosymmetric; K + C tube +), C (0) 4-many and centrifugal, pollen surface variously sculpted, G [2-12], when 2, transverse, (placentation axile; secondary septae +; style +); fruit a berry (transversely schizocarpic; septicidal); tegmen multiplicative, to 6 layers thick, exotegmen radially enlarged, sclerified, endotegmen with lignified bands on anticlinal walls; n = (7-)10(-15+); 6 bp insertion in ndhF gene.

16/480: Capparis (250), Maerua (100), Boscia (37), Cadaba (30). Largely tropical (Map: from Jacobs 1960; Wickens 1976; George 1982; Jalas & Suominen 1991). [Photo - Flower, Fruit.]

• Capparaceae are woody, the inflorescence is racemose, the flowers have a gynophore and often many stamens with long filaments, and the fruit is indehiscent.

Crateva is strongly supported as being sister to the rest of the subfamily, within which there is so far little strong structure; Capparis is probably polyphyletic (Hall et al. 2002).

Crateva has glands (?colleters) at the base of the lamina. Some Capparaceae have supernumerary buds and dry yellowish.

Forchhammeria and perhaps other Stixeae that used to be placed here are properly to be placed in or near Resedaceae; their flowers tend to be 3-, 5- or 6-merous (Hall & Sytsma 2002; Hall et al. 2002), there is no differentiation between the two perianth whorls, and the placentation is axile (see also Kers 2002). Setchellanthus (see Setchellalanthaceae; still Brassicales) also used to be included here.

For general information, see Kers (2002).

Cleomaceae + Brassicaceae: herbaceous annuals (shrubs); inflorescence ± corymbose; C 4, clawed, A 6, G [2]; fruit septicidal, persistent placental strands + (0).

Since Aethionema, with a more or less sessile gynoecium, is sister to all other Brassicaceae, similarities of Stanleya, etc., to Capparaceae and Cleomaceae (e.g. long gynophore) are presumably parallelisms (Galloway et al. 1998). Stanleya, etc., form a clade well embedded in Brassicaceae.

For floral development, see Leins (2000, and references).

CLEOMACEAE Horaninow   Back to Brassicales

Root hairs 0; petiole bundle(s) arcuate; leaves often palmate, (stipules +); bracts foliaceous (not); flowers also monosymmetric, (androgynophore +), anthers linear, coiled at dehiscence, pollen surface variously sculpted, often spinulose; (fruit indehiscent); (seeds arillate); exotegmen cells radially elarged, sclerified, endotegmen cells with lignified bands on periclinal walls; n = 9<.

10/300: Cleome (275: including Podandrogyne). Tropical and warm temperate, esp. America (Map: see Wickens 1976; George 1982; Jalas & Suominen 1991). [Photo - Inflorescence, [Flower.]

• Cleomaceae are herbaceous or shrubby, the inflorescence is racemose, the flowers have four clawed petals, six stamens, and two carpels; the gynoecium has a gynophore, the stamens have long filaments, and the dehiscent fruit has persistent placental strands.

A duplication (hexaploid) of the genome in the family occured ca 20 mybp (it was detected in Cleome spinosa: Schranz & Mitchell-Olds 2006).

Podandrogyne (= Cleome) is monoecious; rather unusually, the staminate flowers are basal on the inflorescence.

Note that in Cleomaceae the inflorescence may be a corymb, there are usually 6 stamens, etc., e.g. Podandrogyne (= Cleome) - also with orange flowers, 3-foliolate leaves and a gynophore. Generic limits are unsatisfactory.

The small-flowered Dipterygium, placed in Capparaceae in a subfamily by itself by Kers (2002), is possibly to be included here. It has six stamens that are all equal in length, a filiform style, a winged, 1-seeded nut, and incumbent cotyledons; methylglucosinolates are recorded from the plant (Hedge et al. 1980).

For general information, see Kers (2002: in Capparaceae), for anther dehiscence, see Mitchell-Olds et al. (2005).

Synonymy: Oxystylidaceae Hutchinson

BRASSICACEAE Burnett, nom. cons.//CRUCIFERAE Jussieu, nom. cons. et nom. alt.   Back to Brassicales

(Nortropane alkaloids +), methyl glucosinolates 0; roots lacking mycorrhizae; cork ?always deep-seated; (included phloem +); stomata anisocytic; hairs variously furcate; (leaves pinnately lobed), stipules 0; bracts 0 (foliaceous); floral development closed, (flowers disymmetric; monosymmetric), A (4), the two outer shorter than the four inner [tetradynamous], about as long as petals, nectary lobes outside inner A, pollen trinucleate, surface often reticulate, gynophore 0 (+), commissural septum +, style often +, short, stigma commissural; seed folded, but no invagination of the coat, testa often mucilaginous, 3-layered, exotestal cells reticulately thickened on radial walls, endotesta palisade, with U-shaped thickenings or not, tegmen multiplicative, not persistent; chalazal endosperm cyst +, endosperm 1-layered; n = (4-)8(-13).

338[list]/3710 - two groups below. World-wide, esp. N. temperate (Map: from Vester 1940; Hultén 1971). [Photos - Collection].

Aethionemeae Al-Shehbaz, Beilstein & E. A. Kellogg

Plant glabrous; nortropane alkaloids +; fruit angustiseptate; n = 7, 8, 11, 12, 14...

1-2/70. The Mediterranean and Europe to Afghanistan (Map: from Mark Menke, pers. comm.). [Photo - Flowers.]

The Rest.

(Eglandular hairs branched, stellate, T-shaped); genome duplication.

338/3710: Draba (365), Cardamine (200: extensive polyploidy and hybridization, see Lihová & Marhold 2006), Erysimum (225), Lepidium (230), Alyssum (195), Arabis (120), Physaria (105: inc. Lesquerella), Rorippa (85), Heliophila (80), Isatis (80), Noccaea (80), Boechera (ex Arabis - 65), Thlaspi (55), Biscutella (55), Matthiola (50), Descurainia (50), Hesperis (45), Sisymbrium s. str. (45: Old World, New World taxa mixed in with Theylpodieae - see Warwick et al. 2002, 2006a). World-wide, esp. N. temperate (but less E. North America, and even more so humid lowland tropics). [Photo - Flowers, Flowers, Fruit.]

• Most Brassicaceae are herbs, and a number of taxa have distinctive small, branched, eglandular hairs. The ebracteate inflorescence is racemose, the flowers have four, clawed petals (the alternate name 'Cruciferae' for this family is taken from the cross-like arrangement of these four petals), six stamens with relatively short filaments (so the anthers are included), the gynoecium has two carpels and a short style, and the dehiscent fruit has both persistent, almost woody placental strands and a membranous false septum.

Stem group Brassicaceae are estimated to be 22-18 myo (Wikström et al. 2001), some 41 myo (Schranz & Mitchell-Olds 2006), or some 50 myo, with divergence of Aethionemeae from the rest ca 40 mybp (Al-Shehbaz et al. 2006). Initial diversification was in the Old World.

It has been suggested that n = 8 is ancestral in the family, with subsequent extensive genome rearrangement (Lysack et al. 2006). Duplication of the whole genome seems also to have occured fairly soon after the split from the Capparaceae and has been dated to 34-25 mybp (Vision et al. 2000; Blanc & Wolfe 2004; Schranz & Mitchell-Olds 2006); see also the findings of Galloway et al. (1998) on the pattern of duplication of the ADC (arginine decarboxylase) gene. There is also extensive genome duplication within the family (Kellogg & Bennetzen 2004), and this has happened more than once (Vision et al. 2000; Blanc & Wolfe 2004). The origin of a trnF pseudogene has been associated with a duplication in the common ancestor of the Halimolobus + Boechera + Cardamine clade, some 21-16 mybp (Koch et al. 2005). "Diploid" species like Brassica oleracea, with n = 9, are hypothesised to be ancestral hexaploids (Mitchell-Olds et al. 2005).

According to Medve (1983), any mycorrhizal associations with the roots of Brassicaceae are at best weak and facultative, and although arbuscular mycorrhizae have recently been reported from Thlaspi, it is doubtful if an effective symbiosis results (Regvar et al. 2003). Indeed, glucosinolates can depress vesicular-arbuscular mycorrhizal activity, a possible element in the invasive capabilities of Alliaria petiolata (Wolfe & Klironomos 2005). Arabidopsis thaliana can take up nitrogen in an organic form as amino acids (Hirner et al. 2006), although the general significance of this is unclear.

Glucosinolate diversity in the family is considerable, as is variation in content between different species in the same community; the presence of particular glucosinolates may induce oviposition by Pieris butterfly, whether or not the species with that glucosinolate is edible or lethal (Chew 1979, see also 1988). Cabbage white caterpillars are able to convert the glucosinolates that are produced when they damage plant tissue in the course of eating into non-toxic nitriles (Wittstock et al. 2004).

Of the genera so far sampled, Aethionema, a variable but poorly known genus with angustiseptate fruits, is sister to the rest of the family (e.g. Zunk et al. 1996, 1999; Koch et al. 2001; Beilstein et al. 2006). Thelypodieae, with their exserted stamens, gynophore, etc., appear to be similar to Capparaceae and to have a plesiomorphic morphology, but are in fact derived within Brassicaceae. The relationships between many of the tribes are still unclear, and there seems to have been a rather rapid radiation of the lineages that encompass most of the diversity of the family today (Beilstein et al. 2006; Al-Shehbaz et al. 2006; Bailey et al. 2006a, b).

Arabidopsis thaliana is of course one of the most important model plants in current biology; the limits of the genus have recently been extended (see Clauss & Koch 2006 for a discussion of its relatives). Genera in Brassicaceae were in the past often based on fruit and embryo differences and their limits are often unsatisfactory, and there has been parallel or convergent evolution of just about all the morphological features used to distinguish genera (Koch 2003; Al-Shehbaz et al. 2006; Bailey et al. 2006a, b). There are major disagreements over generic limits, and intergeneric hybridisation is quite common (see summary in Warwick et al. 2006). Although genera such Draba and Lepidium are monophyletic or largely so on both morphological and molecular grounds, others, such as Brassica, are not (e.g. Mitchell-Olds et al. 2005 and references). Warwick and Sauder (2005) found a monophyletic Brassiceae that needed but little adjustment from its classical delimitation, but "well-known" genera such as Brassica, Diplotaxis, and Erucastrum were polyphyletic; as they noted, this should affect how breeders go about their work. Of late, substantial progress has been made in realigning taxa, and Al-Shehbaz et al. (2006) recognise 25 tribes in which they place 260 of the 338 genera of the family.

The commissural stigmas of Brassicaceae have been supposed to indicate that the gynoecium is basically 4-carpellate. Although such stigmas are common in groups with parietal placentation, there may be normally oriented bundles outside the inverted placental ventral carpellary bundle in Crataeva religiosa, perhaps indicative of an original 4-carpellate condition with axile placentation (Dickison 2000, but cf. Brückner 2000). Another controversy concerns the six stamens - did they arise by dédoublement or by reduction?

The border cells of the root cap dissociate in rows (Driouich et al. 2006); other Brassicales should be examined for this character. There are rarely glandular stipules in the inflorescence and elsewhere (see Weberling 2006 for a summary, also Bowman 2006). Brassicaceae have tryphine, in which some constituents of the disorganised tapetal cells are still visible, covering the pollen grains, not pollenkitt, as in other angiosperms (Pacini & Hesse 2005), although details of the distribution of this feature are unclear. The chalazal endosperm cyst may be involved in the movement of metabolites into the developing seed, there being transfer cells around it (Brown et al. 2004). Bowman (2006) discusses morphology in general in the context of comparative developmental genetics.

See Vaughan and Whitehouse (1971) and Bouman (1975) for ovules and seed coat; Erbar and Leins (1997a, b) for floral development, Al-Shehbaz (1984), Appel and Al-Shehbaz (2002), Koch et al. (2003), Hurka et al. (2005) and Mitchell-Olds et al. (2005) for general information and references; Brown et al. (2004) for the endosperm cyst (Aethionema not sampled, cyst probably not in in Cleome, at least); Lysack et al. (2005) for chromosome triplication in Brassiceae; Warwick and Al-Shehbaz (2006) for a summary of chromosome numbers; Grubb and Abel (2006) for glucosinolate metabolism; Brock et al. (2006) for nortropane alkaloids (in both Aethionema and Cochlearia, i.a.); Beilstein et al. (2006) for trichome evolution; Koch and Kiefer (2006) for a summary of biogeographic studies; Warwick and Al-Shehbaz (2006) for chromosome numbers; Marhold and Lihová (2006) for hybridization and polyploidy; and Price et al. (1994), Galloway et al. (1998), Koch et al. (2001), Koch (2003), Beilstein et al. (2006) and Warwick et al. (2007) for phylogeny. Warwick et al. (2006b) provide a species checklist and Schweingruber (2006) gives details of phloem and xylem anatomy.

Synonymy: Drabaceae Martynov, Erysimaceae Martynov, Raphanaceae Horaninow, Sisymbriaceae Martynov, Stanleyaceae Nuttall, Thlaspiaceae Adanson