annual : a plant that completes its life cycle (from seed to seed) within a single growing season. A spring annual is a plant that is grown in the ground in late winter, is planted in the spring and then completes its life cycle by midsummer
basal : growing at the base or bottom of a plant
berry : a type of fruit with seeds contained in or about the pulp or flesh
biennial : any plant needing two seasons of growth (with a dormant period between growth stages) to complete its life cycle, from seed to seed. In the first year, plants form vegetative growth, and in the second year they flower
bract : a modified leaf that may occur at the base of a flower or stalk. In the dogwood, white or pink bracts surround the flowers, giving the casual viewer the impression that these leaves are petals
broadleaf : having broad and flat leaves that persist from year to year
calyx : the group of sepals, or outer floral leaves, of a flower
catkin : a dry and scaly flowering spike
chlorosis : a symptom of disease or disorder in plants in which a plant or part of a plant is light green or greenish-yellow because of poor chlorophyll development or destruction of chlorophyll
corymb : a flat or convex cluster of flowers in which the flowers lie as a dome or dish
crest : an elevated ridge on a surface, such as the ridges on a flower petal
cultivar — a cultivated variety or strain of a plant produced by horticultural techniques and not normally found in wild populations. A cultivar name is written after the Latin name, usually marked by single quotation marks, as in Zinnia elegans ‘Tom Thumb’.
culture : a small segment of a plant grown in a nutrient-rich medium; asexual reproduction
deciduous : shedding foliage each year, as applied to trees and shrubs; losing fruit or leaves at maturity or at the end of the growing season; not evergreen
dioecious : having a type of sex expression in which plants produce male and female flowers on separate plants
drupe : a type of fruit with a fleshy outer layer and a hard, nutlike core, such as peaches or cherries
evergreen : having persistent leaves with a crown that is never wholly bare, as applied to a tree or shrub
exfoliate : to peel away in thin layers
ex situ — Latin, at its simplest meaning "out of its proper position." This term denotes plants outside of their native habitat(s). Ex situ plant conservation is the conservation, propagation or preservation of a plant outside of its native or natural habitat.
family : in the Linnaean classification scheme, a category between order and genus that is a group of closely related genera or (rarely) a single genus; an onion is scientifically considered in the genus Allium, of the family Liliaceae, in the order Liliales
genus — in the Linnaean classification scheme, a category between family and species that is a group of similar organisms; a genus consists of one or more species. An elm may be scientifically known as a member of the genus Ulmus and the family Ulmaceae.
habit : the overall appearance of a plant
herbaceous : not woody; referring to plants whose tops are killed back by frost but whose roots and crowns remain alive and send out top growth when favorable growing conditions return
hybrid : the product of a cross between two genetically different parents
in situ — Latin, at its simplest literally meaning "In its proper position." This term denotes plants in their native or natural habitat(s). In situ plant conservation would be the conservation of a plant within its native habitat.
intraspecific — pertaining to any taxon within a species, as a subspecies.
monoecious : having a type of sex expression in which plants produce male and female structures on the same plant
native : indigenous or occurring naturally in a given geographic locale and therefore not introduced by humans either accidentally or intentionally
naturalize : to encourage a plant to grow and spread in an area as if it were native, that is, so that the plant then maintains itself without further human intervention
panicle : a loosely branched, pyramidal cluster of flowers
perennial : a plant that normally lives more than two growing seasons and, after an initial period, produces flowers annually
pH : the reciprocal of the hydrogen ion concentration of a medium. A value on a scale of 0 to14 gives a measure of the acidity or alkalinity of a medium; pH values of 0 to 6.5 indicate acidic conditions, a pH value of 7.0 is neutral and pH values greater than 7.0 are alkaline
pome : a type of fruit with flesh derived from an enlarged receptacle growing around an ovary; apples and pears are examples of pomes
propagate : to increase numbers of or perpetuate a species by sexual (seed) or asexual reproduction
prostrate : lying flat on the ground
raceme : a stalk that continues to grow and on which flowers are borne on individual stems; the lily-of-the-valley features racemes of white flowers
reflexed : bent or curved backward
rhizome : a creeping underground stem, usually horizontal, that produces roots and leaves at the nodes
rosette : a plant growth habit whereby leaves radiate from the crown or center of the stem with very short internodes; many biennials exhibit rosette-type growth in their first year
samara : a dry, winged fruit consisting of a single seed, as of maple and ash
sepal : an individual leaf that is part of the outer floral leaves, usually greenish
species — the basic unit of Linnaean classification; a taxonomic subdivision of genus represented by plants that can freely interbreed but rarely with other species. In the Latin name Ulmus americana, the genus is Ulmus and the species epithet is americana; together, Ulmus americana constitutes the species.
spike : stalkless flowers occurring singly or in clusters
stamen : the male reproductive structure of a flower consisting of the anther (pollen producer) and a slender filament
stolon : a stem that grows horizontally above the ground and may produce roots and shoots at the nodes (e.g., a runner)
sucker : a rapidly growing shoot developing from an underground root or stem
taxon (pl., taxa) — a category of organisms based on their relatedness. The organisms contained within a taxonomic group (i.e., genus, species, cultivar) can be referred to as taxa.
terminal : at the tip or end
trade name : an arbitrary name created by a nursery or other organization to distinguish its product from all others and to protect it legally from misuse
woody plant : any plant that creates branches and stems that do not die in the winter
zone : a region that differs significantly by climate and temperature range from all adjacent areas
