The Families of Flowering Plants


L. Watson and M. J. Dallwitz

Palmae Juss.

Alternatively Arecaceae Schultz-Schultzenst. (nom. altern.)

Including Acristaceae O.F. Cook, Borassaceae O.F. Cook, Caryotaceae O.F. Cook, Ceroxylaceae O.F. Cook, Chamaedoreaceae O.F. Cook, Coryphaceae Schultz-Schultzenstein, Geonomaceae O.F. Cook, Iriarteaceae O.F. Cook, Lepidocaryaceae O.F. Cook, Malortieaceae O.F. Cook, Manicariaceae O.F. Cook, Nipaceae Brongniart ex Martinet, Nipaceae Chadef. & Emberg., Nypaceae (Engl. & Gilg) Tralau, Phoenicaceae Schultz-Schultzenst., Phytelephanteae (Phytelephantaceae) Mart., Phytelephasieae (Phytelephasiaceae) Chadef. & Emberg., Pseudophoenicaceae O.F. Cook, Sabalineae (Sabalaceae) Schultz-Schultzenst., Sagoineae (Sagoaceae) Schultz-Schultzenst., Synechanthaceae O.F. Cook

Habit and leaf form. Trees, or ‘arborescent’, or shrubs, or lianas (rarely diminutive undershrubs). Self supporting, or climbing; often scrambling (by means of hooks on prolonged rachides, leaflets modified as spines, armed sterile inflorescence axes, etc.). Pachycaul. Mesophytic, or xerophytic. Leaves evergreen; small to very large; alternate; spiral, or distichous; leathery; petiolate; sheathing. Leaf sheaths tubular; with joined margins (but often splitting at maturity). Leaves nearly always compound; epulvinate; (falsely) pinnate, or palmate, or bipinnate (rarely). Lamina without cross-venules. Leaves ligulate (often, in palmate and costa-palmate forms), or eligulate; without a persistent basal meristem (presumably). Vernation conduplicate. Leaves becoming compound by ontogenetically predetermined splitting.

General anatomy. Plants with ‘crystal sand’ (occasionally), or without ‘crystal sand’. Plants with silica bodies (hatshaped, spheroidal or ellipsoidal, occurring universally). Accumulated starch other than exclusively ‘pteridophyte type’.

Leaf anatomy. Epidermis without differentiation into ‘long’ and ‘short’ cells; containing silica bodies, or without silica bodies. Stomata mostly tetracytic.

The mesophyll containing calcium oxalate crystals. The mesophyll crystals raphides (usually), or solitary-prismatic (or as crystal sand). Minor leaf veins without phloem transfer cells (Chamaerops). Vessels present; end-walls scalariform.

Stem anatomy. Secondary thickening absent (or slight, and then not cambial but from divisions in the ground parenchyma). Xylem with vessels. Vessel end-walls mostly oblique; scalariform, or simple, or scalariform and simple. Sieve-tube plastids P-type; type II.

Root anatomy. Root xylem with vessels (mostly with transverse end walls); vessel end-walls nearly always simple.

Reproductive type, pollination. Plants hermaphrodite (rarely), or monoecious, or dioecious, or polygamomonoecious. Floral nectaries present, or absent. Nectar secretion when produced, from the gynoecium (via septal nectaries), or from the androecium (via nectaries associated with the stamen bases). Pollination anemophilous, or entomophilous (more often).

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in panicles (usually, and usually complex). The terminal inflorescence unit cymose. Inflorescences axillary (usually), or terminal; usually complex panicles; usually spatheate. Flowers small; more or less regular; 3 merous; cyclic (usually), or partially acyclic. Rarely the perianth acyclic, or the androecium acyclic. Perigone tube present, or absent.

Perianth with distinct calyx and corolla, or of ‘tepals’, or vestigial to absent (rarely); 6 (usually), or 4, or 4–9 (rarely, when spiral); free, or joined; 2 whorled (usually 3+3, occasionally 2+2), or 1 whorled (rarely); isomerous (but the two whorls usually more or less dissimilar); sepaloid, or petaloid, or sepaloid and petaloid; when biseriate, usually different in the two whorls; usually white, or cream.

Androecium 3, or 6, or 9, or 10–900 (i.e. occasionally very numerous). Androecial members free of the perianth, or adnate (to the perianth); free of one another, or coherent; 1 adelphous (filaments often united into a tube or cup); 2 whorled, or 3 whorled (or acyclic). Androecium exclusively of fertile stamens, or including staminodes (? — assuming that references to staminodes refer to male-fertile flowers). Stamens 3, or 6, or 9, or 10–900 (or more); isomerous with the perianth, or diplostemonous (usually), or triplostemonous to polystemonous. Anthers dehiscing via longitudinal slits; latrorse; tetrasporangiate. Endothecium developing fibrous thickenings. The endothecial thickenings spiral. Anther epidermis persistent. Microsporogenesis successive, or simultaneous. The initial microspore tetrads tetrahedral, or isobilateral, or T-shaped, or linear. Anther wall initially with more than one middle layer. Tapetum glandular. Pollen grains aperturate; 1 aperturate (usually), or 2 aperturate; sulcate (usually, sometimes trichotomosulcate), or sulculate (2-sulculate); 2-celled.

Gynoecium 3(–10) carpelled. Carpels isomerous with the perianth, or increased in number relative to the perianth. The pistil when syncarpous, 1 celled, or 3(–10) celled. Gynoecium apocarpous, or syncarpous (occasionally pseudomonomerous); eu-apocarpous, or synovarious to synstylovarious. Ovary when syncarpous 1 locular (rarely, by abortion of the other locules), or 3(–10) locular. Gynoecium non-stylate, or stylate. Styles 1, or 3(–10); when not completely joined, free to partially joined. Stigmas dry type; papillate; Group II type. Placentation sub apical, or basal (or ‘lateral’). Ovules 1 per locule; non-arillate; orthotropous, or anatropous, or campylotropous, or hemianatropous; bitegmic; crassinucellate. Outer integument contributing to the micropyle. Embryo-sac development Polygonum-type (usually), or Allium-type (rarely). Polar nuclei fusing prior to fertilization. Antipodal cells formed, or not formed (then the three nuclei degenerating early); when formed, 3; not proliferating; ephemeral, or persistent. Synergids pear-shaped. Endosperm formation nuclear. Embryogeny onagrad, or asterad.

Fruit fleshy, or non-fleshy; an aggregate (occasionally), or not an aggregate. The fruiting carpel when apocarpous (i.e. rarely), indehiscent; drupaceous. Fruit indehiscent (usually), or dehiscent (rarely); nearly always a berry, or a drupe (sometimes with a fibrous mesocarp). The drupes with one stone (often having the seed united with the endocarp). Gynoecia of adjoining flowers not forming a multiple fruit. Fruit 1 seeded. Seeds endospermic. Endosperm ruminate, or not ruminate; oily (usually), or not oily. Seeds usually without starch. Cotyledons 1. Embryo achlorophyllous (9/9). Testa without phytomelan.

Seedling. Germination cryptocotylar (regardless of the structure of the cotyledon). Hypocotyl internode absent. Mesocotyl absent. Seedling collar not conspicuous. Cotyledon hyperphyll elongated to compact; non-assimilatory. Coleoptile present, or absent. Seedling cataphylls absent. First leaf dorsiventral. Primary root persistent, or ephemeral.

Physiology, biochemistry. Not cyanogenic. Alkaloids present (occasionally, pyrimidine), or absent. Proanthocyanidins present (usually, abundantly), or absent (e.g. Livistonia); cyanidin. Flavonols present (rarely), or absent; when present, kaempferol and quercetin (also tricin, luteolin, etc.). Saponins/sapogenins present (occasionally), or absent. C3. C3 physiology recorded directly in Borassus, Cocos, Phoenix. Anatomy non-C4 type (Archantophoenix, Areca, Arenga, Borassus, Calamus, Caryota, Chrysalidocarpus, Cocos, Cyrtostachys, Elaeis, Eugeissonia, Iguanura, Licuala, Livistona, Nypa, Oncosperma, Phoenix, Pinanga, Ptychosperma, Roystonea).

Geography, cytology. Sub-tropical to tropical. Pantropical and subtropical. X = 13–18. Ploidy levels recorded: only in Areca.

Taxonomy. Subclass Monocotyledonae. Superorder Areciflorae; Arecales. APG (1998) Monocot; Commelinoid group; Arecales. Species about 2500. Genera about 205; Acanthophoenix, Acoelorrhaphe, Acrocomia, Actinokentia, Actinorhytis, Aiphanes, Allagoptera, Alloschmidia, Alsmithia, Ammandra, Antongilia, Aphandra, Archontophoenix, Areca, Arenga, Asterogyne, Astrocaryum, Attalea, Bactris, Balaka, Barcella, Basselinia, Beccariophoenix, Bentinckia, Bismarckia, Borassodendron, Borassus, Brahea, Brassiophoenix, Brongniartikentia, Burretiokentia, Butia, Calamus, Calospatha, Calyptrocalyx, Calyptrogyne, Calyptronoma, Campecarpus, Carpentaria, Carpoxylon, Caryota, Catoblastus, Ceratolobus, Ceroxylon, Chamaedorea, Chamaerops, Chambeyronia, Chelyocarpus, Chrysalidocarpus, Chuniophoenix, Clinosperma, Clinostigma, Coccothrinax, Cocos, Colpothrinax, Copernica, Corypha, Cryosophila, Cyphokentia, Cyphophoenix, Cyphosperma, Cyrtostachys, Daemonorops, Deckenia, Desmoncus, Dictyocaryum, Dictyosperma, Drymophloeus, Dypsis, Elaeis, Eleiodoxa, Eremospatha, Eugeissona, Euterpe, Gastrococos, Gaussia, Geonoma, Goniocladus, Gronophyllum, Guihaia, Gulubia, Halmoorea, Hedyscepe, Heterospathe, Howeia, Hydriastele, Hyophorbe, Hyospathe, Hyphaene, Iguanura, Iriartea, Iriartella, Itaya, Jessenia, Johannesteijsmannia, Juania, Jubaea, Jubaeopsis, Kentiopsis, Kerriodoxa, Korthalsia, Laccospadix, Laccosperma, Latania, Lavoixia, Lemurophoenix, Leopoldinia, Lepidocaryum, Lepidorrhachis, Licuala, Linospadix, Livistona, Lodoicea, Louvelia, Loxococcus, Lytocaryum, Mackeea, Manicaria, Marojejya, Masoala, Mauritia, Mauritiella, Maxburretia, Maximiliana, Medemia, Metroxylon, Moratia, Myrialepis, Nannorrhops, Nenga, Neodypsis, Neonicholsonia, Neophloga, Neoveitchia, Nephrosperma, Normanbya, Nypa, Oenocarpus, Oncocalamus, Oncosperma, Orania, Oraniopsis, Orbigyna, Palandra, Parajubaea, Pelagodoxa, Phloga, Phoenicophorium, Phoenix, Pholidocarpus, Pholidostachys, Physokentia, Phytelephas, Pigafetta, Pinanga, Plectocomia, Plectocomiopsis, Podococcus, Pogonotium, Polyandrococos, Prestoea, Pritchardia, Pritchardiopsis, Pseudophoenix, Ptychococcus, Ptychosperma, Raphia, Ravenea, Reinhardtia, Retispatha, Rhapidophyllum, Rhapis, Rhopaloblaste, Rhopalostylis, Roscheria, Roystonea, Sabal, Salacca, Satakentia, Scheelea, Schippia, Sclerosperma, Serenoa, Siphokentia, Socratea, Sommieria, Syagrus, Synechanthus, Tahina, Tectiphiala, Thrinax, Trachycarpus, Trithrinax, Veillonia, Veitchia, Verschaffeltia, Voanioala, Vonitra, Wallichia, Washingtonia, Welfia, Wendlandiella, Wettenia, Wodyetia, Ynesa, Zombia.

Economic uses, etc. Pantropically of great economic importance: coconut products, oils, dates, ivory nuts, carnauba wax, rattan cane, raffia, etc.

Illustrations. • Technical details (Chamaerops). • Technical details: Areca (betel), Caryota, Metroxylon. • Fruit structure: Cocos, Cucifera (= Hyphaene), Saguerus (= Arenga). • Habit and inflorescence: Chamaedorea, Livistonia, Seaforthia. • Fruit and seed details: Phoenix dactylifera. • Rhapis flabelliformis: habit and technical details. • Raphia laurentii: habit, fruit and seed (Thonner). • Raphia laurentii: inflorescence and flowers (Thonner).


(The male palm marries the female palm) ‘by gentle sighings, tender looks, and the dispersion of a powder’
(Pliny’s ‘Natural History’ (First Century A.D.). Fifteen wasted centuries later, Parkinson (1640) accounts this belief ‘of the ancient writers . . . among the rest of their fables’. See Gilmour’s ‘British Botanists’ (1956, Collins))

This description is offered for casual browsing only. We strongly advise against extracting comparative information from it. This is much more easily achieved using the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting specified attributes, summaries of attributes within groups of taxa, geographical distribution, genera included in each family, classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG), and notes on the APG classification.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 25th November 2008.’.