Botanical Terms

                 (If you are unable to find the term you are looking for, or wish to see illustrations of particular botanical characteristics, I recommend Plant Identification Terminology by James G. Harris and Melinda Woolf Harris, from which many of these definitions have been taken)

A

• Acaulescent: stemless
• Accumbent: a term referring to seeds in which the embryonic root is wrapped around and lies along the edges of the two cotylodons (compare incumbent)
• Acerose: needle-shaped
• Achene: a small, dry, one-seeded, indehiscent fruit (i.e. one that does not split open), deriving from a one-chambered ovary, typical of the Asteraceae
• Acicular: needle-shaped, as applied to some kinds of foliage
• Actinomorphic: radially symmetrical
• Aculeate: pointed or prickly
  
• Acuminate: tapering gradually to a pointed apex with more or less concave sides along the tip
  
• Acute: tapering to a sharp-pointed apex with more or less straight sides along the tip
• Acyclic: with the floral parts arranged spirally rather than in whorls
• Adenophorous: gland-bearing
• Adherent: two or more organs appearing to be fused but actually separable
• Adnate: grown together, used only to describe unlike parts (compare connate)
• Adpressed: closely pressed together but not united
• Aduncate: hooked
• Adventitious: occurring in unusual or unexpected locations such as roots on aerial stems or buds on leaves. Also meaning: out of the usual place, introduced but not yet naturalized
• Adventive: see adventitious
• Aequilateral: equal-sided, as opposed to oblique
• Aestivate: to become dormant in summer
• Aggregate: densely clustered
• Aianthous: flowering constantly
• Alate: having wings or wing-like structures
• Alkaline: soils that contain high amounts of various salts of potassium and/or sodium, as well as other soluble minerals, and are basic rather than acidic with a Ph greater than 7.0
• Allelopathy: a characteristic of some plants according to which chemical compounds are produced that inhibit the growth of other plants in the immediate vicinity
• Allopatric: occupying different geographic regions
  
• Alternate: a leaf arrangement along the axis in which the leaves are not opposite to each other or whorled
• Ammophilous: sand-loving
• Amplexicaul: describing a sessile leaf that has its base completely surrounding the stem
• Anandrous: without stamens
• Ananthous: without flowers
• Ancipital: two-edged, such as the winged stem of Sisyrinchium
• Androecium: a collective term for the stamens of a flower (compare gynoecium)
• Androgynous: having staminate and pistillate flowers in the same inflorescence
• Anemophilous: wind-pollinated
• Angled: sided, as in the shape of stems or fruits
• Angular: having sharp angles or corners, generally used in reference to structures such as stems to contrast them with rounded stems
• Annual: a plant that completes its life cycle from the its germination as a seed to the production of new seeds in a single year and then dies
• Annular: in the form of a ring
• Anterior: on the front side away from the axis
  
• Anther: the pollen-bearing portion of a stamen
• Anthesis: time during which the flower is open
• Antrorse: pointing forward or upward (compare retrorse)
• Aperturate: with one or more openings or apertures
• Apetalous: lacking petals
• Apex: the tip of a plant part
• Aphyllous: without leaves
• Apiculate: ending in an abrupt slender tip which is not stiff
• Applanate: flattened
  
• Appressed: lying flat against or nearly parallel to, as leaves on a stem or hairs on a leaf
• Arborescent: approaching the size and habit of a tree
• Arcuate: arching or curved like a bow
• Areole: a raised area on a cactus from which spines develop
• Aristate: with an awn or stiff bristle, typically at the apex
• Armed: provided with prickles, spines or thorns
  
• Ascending: growing obliquely upward
• Asperous: rough to the touch
• Asteraceae: sunflower family
• Asymmetrical: not divided into like and/or equal parts
• Attenuate: gradually narrowing to a tip or base
  
• Auricle: a small earlike lobe or appendage
  
• Auriculate: having earlike appendages
• Austral: southern (compare boreal)
• Autophilous: self-pollinated
  
• Awn: a slender, stiff terminal bristle attached at its base to another structure or organ such as a leaf or grass stem
  
• Axil: the upper angle formed between two structures or organs, such as a leaf and the stem from which it grows
• Axillary: borne or carried in the axil
• Axis: the main stem

  B

• Baccate: like a berry, having berries
• Balsamiferous: sticky and aromatic, like balsam
• Banner: the upper petal of a pea flower
• Barbed: with a backward-facing tip
• Basal: at or near the base, often describing leaves and where they attach
• Basifixed: attached by the base (compare dorsifixed, versatile)
• Beak: a firm, pointed terminal appendage
• Berry: a fleshy, indehiscent fruit in which the seeds are not encased in a stone and are typically more than one
• Biennial: a plant that takes two years to complete its life cycle, usually growing vegetation in the first year and producing flowers and seeds in the second, then dying
• Bifarious: in two vertical rows
• Bifid: two-lobed or two-cleft
• Biflorous: flowering in the spring and again in the autumn
• Bifurcate: divided into two forks or branches
• Bilabiate: two-lipped
• Bipinnate: twice pinnately compound
• Bipinnatifid: two times pinnately cleft
• Bisexual: having both stamens and pistils
• Bladdery: thin-walled and inflated
• Blade: the expanded terminal portion of a leaf, petal or other structure, i.e. that portion of the leaf that does not include the stalk
• Bloom: a white, powderlike coating sometimes found on a leaf or stem surface
• Bole: the trunk or stem of a tree
• Boreal: northern (compare austral)
• Brackish: a mixture of salt and fresh water, somewhat saline
• Bract: a modified leaf which may be reduced in size or different in other characteristics from the foliage leaves and which usually subtends a flower or an inflorescence
• Brassicaceae: mustard family
• Bristle: a stiff hair, usually erect or curving away from its attachment point
• Brunescent: brownish
• Bud: a developing leaf, stem or flower
• Bulb: an underground plant part derived from a shoot that is enclosed in numerous overlapping thickened leafy scales whose purpose is to store food
• Bulblet: a small bulb produced at the base of a bulb
• Bullate: blistered or puckered
• Bundle scar: scar left on a twig by the vascular bundles when a leaf falls
• Bur: a prickly or spiny seed or fruit
• Burl: a woody swelling where the stem joins the roots

  C

• Caducous: falling off very early as compared to similar structures in other plants
• Caerulescent: bluish
• Caespitose: growing in tufts
• Calathiform: basket- or cup-shaped
• Calciphilous: lime-loving
• Callus: a hardened or thickened area at the point of attachment
• Calyx: the outer whorl of the perianth, composed of the sepals, usually but not always green, which enclose other flower parts in bud
• Campanulate: bell-shaped
• Canescent: with gray or white short hairs, often having a hoary appearance
• Capillary: very slender and hairlike
• Capitate: in a globular or head-shaped cluster
• Capitulescence: a special term used in Asteraceae to describe a group of associated heads--also called capitula; it is analogous to an inflorescence)
• Capitulum: a raceme consisting of a tightly packed head of almost stalkless flowers, as in the Asteraceae
• Capreolate: with tendrils
• Capsule: a dry, generally many-seeded fruit divided into two or more seed compartments that dehisces or splits open longitudinally with the line of dehiscence either through the locule (loculicidal) or through the septa (septicidal), or, less commonly, through pores (poricidal) or around the circumference (circumscissile)
• Carinate: keeled with one or more longitudinal ridges
• Carpel: a simple pistil, or a single unit of a compound pistil, the ovule-bearing portion of a flower
• Caryopsis: the grain or fruit of grasses
• Castaneous: dark reddish-brown
• Catkin: a spikelike, often pendulous, inflorescence of petalless unisexual flowers, either staminate or pistillate
• Caudate: bearing a tail or slender tail-like appendage
• Caudex: the persistent, often woody base of an otherwise annual herbaceous stem
• Cauline: attached to or referring to the stem, as opposed to 'basal', often used to describe leaf position
• Cernuous: nodding, drooping
• Cespitose: having a densely clumped, tufted or cushion-like growth form with the flowers extending above the clump
  
• Chaff: thin scales or bracts subtending individual flowers in many species of the Asteraceae
• Chaparral: an area characterized by dense, leathery-leaved, evergreen shrubs
• Chlorophyllous: of or containing chlorophyll
• Chlorotic: lacking chlorophyll
• Cilia: marginal hairs
• Ciliate: with a row of fine hairs situated along the margin of a structure such as a leaf
• Ciliolate: with a marginal fringe of minute hairs
• Cinereous: ash-colored, light-gray due to a covering of short hairs
• Circumboreal: distributed around the globe at northern latitudes
• Circumsessile: dehiscing along a transverse circular line around the fruit or anther, so that the top separates or falls off like a lid
• Cismontane: referring to the ocean-facing side as opposed to the desert-facing side of the mountains
• Citreous: lemon-yellow
• Clasping: having the lower edges of a leaf blade partly surrounding the stem
• Clavate: club-shaped, gradually thickened or widened toward the apex
• Claw: the narrow, basal stalklike portion of some sepals and petals
• Cleft: deeply cut, usually more than one-half the distance from the margin to the midrib or base
• Cleistogamous: self-fertilizing, flowers not opening
• Collar: in grasses the outer side of the leaf at the junction of the sheath and blade
• Coma: a tuft of hairs, often at the tip of seeds
• Complete: describing flowers that contain petals, sepals, pistils and stamens
• Composite: a member of the Asteraceae, or sunflower family, previously called the Compositae
• Compound: made up of two or more similar parts, as in a leaf which has leaflets
• Concolor: of uniform color
• Confluent: running together or blending of one part into another
• Connate: Describing similar structures that are joined or grown together (compare adnate)
• Connivent: converging, but not actually fused or united
• Conspecific: of the same species
• Contracted: narrowed or shortened as opposed to open or spreading
• Convolute: rolled up longitudinally, with one edge inside the other and the upper surface on the inside (compare revolute, involute)
• Cordate: heart-shaped
• Coriaceous: leathery in texture
• Corm: an enlarged underground structure that consists of stem tissue and thin scales
• Corneous: horny
• Corniculate: having little horns or hornlike appendages
• Cornute: horned
• Corolla: the inner whorl of the perianth, between the calyx and the stamens, a collective term for the petals of a flower
• Coroniform: crown-shaped
• Corrugated: wrinkled, folded
• Corymb: a broad, flat-topped inflorescence in which the flower stalks arise from different points on the main stem and the marginal flowers are the first to open (compare cyme)
• Costate: ribbed, having longitudinal elevations
• Crenate: with shallow roundish or bluntish teeth on the margin, scalloped
• Crenulate: similar to crenate, but with smaller, rounded teeth
• Crisped: curled on the margin like a strip of bacon
• Cristate: with a terminal tuft or crest
• Cruciform: cross-shaped
• Crustaceous: dry and brittle
• Cucullate: hooded or hood-shaped
• Culm: a hollow or pithy slender stem such as is found in the grasses and sedges
• Cultivar: a form of a plant derived from cultivation
• Cuneate: wedge-shaped, with the narrow part at the point of attachment
• Cupule: a cup-shaped involucre, as in an acorn
• Cuspidate: tipped with an abrupt short, sharp, firm point (compare mucronate)
• Cyathiform: cup-shaped
• Cyathium: the specialized inflorescence characteristic of the Euphorbiaceae, consisting of a flower-like, cup-shaped involucre which carries the several true flowers within
• Cyme: a broad, flat-topped inflorescence in which the central flower is the first to open (compare corymb)

  D

• Deca-: a prefix meaning ten

• Decumbent: prostrate at the base but ascending at the end

• Decurrent: adnate to the petiole or stem and extending downward, as a leaf base that extends downward along the stem (compare surcurrent)
• Decussate: arranged in pairs along the stem with each pair at right angles to the one above and below
• Deflexed: Bent downward or backward

• Dehiscent: opening spontaneously when ripe to discharge the seed content (compare indehiscent)

• Deltoid: broadly triangular in shape

• Dense: congested, describing the disposition of flowers in an inflorescence (compare open)

• Dentate: with sharp, outward-pointing teeth on the margin

• Depauperate: starved or stunted, describing small plants or plant communities that are growing under unfavorable conditions
• Determinate: describes an inflorescence in which the terminal flower blooms first, thereby halting further elongation of the flowering stem (compare indeterminate)
• Dextrorse: turned to the right or spirally arranged to the right (compare sinistrorse)
• Di-: prefix meaning two or twice
• Diandrous: having two stamens
• Dichotomous: branching regularly and repeatedly in pairs
• Dicotyledon: a plant having two seed leaves, one of the two major divisions of flowering plants (compare monocotyledon)
• Didymous: twinned, being in pairs
• Didynamous: with two pairs of stamens of unequal length
• Diffuse: looosely branching or spreading
• Digitate: radiating from a common point, having a fingered shape, i.e. a shape like an open hand
• Digynous: having two pistils
• Dimorphic: having two forms

• Dioecious: having staminate and pistillate flowers on separate plants (compare monoecious)

• Disciform: having a flowering head that contains both filiform and disk flowers, referring to members of the Asteraceae
  

• Discoid: having only disk flowers, referring to flower heads in the Asteraceae

• Disjunct: separated from the main distribution of the population
• Disk: the central portion of composite flowers, made up of a cluster of disk flowers
• Dissected: finely cut or divided into many, narrow segments
• Distal: the end opposite the point of attachment, away from the axis (compare proximal)
• Distichous: two-ranked, that is with leaves on opposute sides of a stem and in the same plane
• Distinct: having separate, like parts, those not at all joined to each other, often describing the petals on a flower (compare united)
• Disturbed: referring to habitats that have been impacted by the actions of people
• Diurnal: growing in the daytime

• Divaricate: widely diverging or spreading apart

• Divergent: diverging or spreading

• Divided: cut deeply, nearly or completely to the midrib

• Dodeca-: prefix meaning twelve
• Dorsal: referring to the back or outer surface
• Dorsifixed: attached at the back (compare basifixed, versatile)
• Drooping: erect or spreading at the base, then bending downwards

• Drupe: a fleshy indehiscent fruit enclosing a nut or hard stone containing generally a single seed such as a peach or cherry

  E

• E-: prefix usually meaning without
• Ebeneous: black
• Eccentric: off-center, not positioned directly on the central axis
• Echinate: prickly
• Ecotone: transition zone between two adjoining communities
• Ecotype: those individuals adapted to a specific environment or set of conditions
• Elliptic: broadest near the middle and tapering gradually to both ends
• Elongate: stretched out, many times longer than broad
• Emarginate: with a shallow notch at the apex
• Endemic: confined to a limited geographic area
• Endocarp: the inner layer of the pericarp, which is the wall of the ripened ovary or fruit (compare mesocarp, exocarp)
• Ensiform: sword-shaped, as applied to a leaf
• Entire: describing a leaf that has a continuous, unbroken margin with no teeth or lobes
• Entomophilous: insect-pollinated
• Ephemeral: describes a plant or flower that lasts for only a short time or blooms only occasionaly when conditions are right
• Epigynous: with stamens, pistils, and sepals attached to the top of the ovary (compare hypogynous)
• Erose: having an irregular margin as if it has been gnawed
• Escapee: a plant that has escaped from cultivation and now reproduces on its own
• Evanescent: fleeting, lasting for only a short time
• Even-pinnate: a pinnately-compound leaf ending in a pair of leaflets (compare odd-pinnate)
• Exfoliating: peeling off in thin layers or flakes
• Exocarp: the outer layer of the pericarp of a fruit (compare endocarp, mesocarp)
• Exotic: not native, introduced from another area
• Exserted: projected from or extending beyond, as stamens from a flower
• Extant: still surviving, not completely extinct
• Extirpated: destroyed or no longer surviving in the area being referred to, but may survive outside of that area
• Extrorse: turned or opening outward away from the axis (compare introrse)
• Exudate: a substance exuded or secreted from a plant
  

  F

• Fabaceae: pea family
• Fagaceae: oak family
• Falcate: scimitar- or sickle-shaped
• Farinose: covered with a mealy or whitish powdery substance
• Fascicle: a small cluster or bundle, a fairly common leaf arrangement
• Fastigiate: clustered, parallel and erect, having a broom-like appearance
• Fenestrate: with small slits or areas thinned so as to be translucent
• Ferruginous: rust-colored
• Fertile: having the capacity to produce fruit, having a pistil
• Filament: the basal, sterile portion of a stamen below the anthers
• Filiform: (1) threadlike; (2) a type of flower in the Asteraceae which is pistillate and has a very slender, tubular corolla
• Fimbriate: having fringed margins
• Fistulose: hollow like a tube or pipe
• Flabellate: fan-shaped, as in a fan-shaped structure
• Flaccid: soft and weak, limp
• Flange: a projecting rim or edge
• Flavescent: yellowish
• Flexuose or flexuous: with curves or bends, somewhat zigzagged
• Floc: a tuft of soft, woolly hair
• Floccose: wooly, covered with soft wooly tufted hairs that are usually easily rubbed off
• Floret: a small individual flower in a flower head
• Floricane: the second-year flowering and fruiting cane or shoot of Rubus (compare primocane)
• Fluted: with furrows or grooves
• Foliolate: having leaflets
• Follicle: a dry, many-seeded fruit derived composedof a single carpel l and opening along one side only like a milkweed pod
• Forb: a non-grasslike herbaceous plant
• Fovea: a small pit or depression
• Frond: a fern leaf
• Fructiferous: fruit-bearing
• Frutescent: shrubby or bushy in the sense of being woody
• Fulvous: dull yellowish-brown or yellowish-gray, tawny
• Funnelform: gradually widening upwards, as in the flowers of morning glory
• Furcate: forked
• Furfuraceous: scurfy, branlike, flaky
• Fuscous: dark grayish-brown, dusky
• Fusiform: spindle-shaped, thickest in the middle and drawn out at both ends

  G

• Gall: an abnormal growth on a plant that is caused by insects
• Geniculate: bent abruptly like a knee or a stove pipe
• Glabrate: becoming glabrous in age
• Glabrous: smooth, without hairs
• Gland: a depression or protuberance that exists for the purpose of secreting
• Glandular: producing tiny globules of sticky or oily substance
• Glans: a dry dehiscent fruit borne in a cupule, such as the acorn
• Glaucescent: slightly glaucous
• Glaucous: covered with a thin, light-colored waxy or powdery bloom
• Globose: globe-shaped, spherical
• Glochids: barbed bristles on cacti
• Glomerate: crowded, congested or compactly clustered
• Glume: in grasses, the bracts (generally two) that form the lowermost parts of the spikelet
• Glutinous: having a sticky surface
• Gracile: slender and graceful
• Grain: the fruit of grasses
• Gregarious: growing in groups or colonies
• Grenadine: bright red
• Gynobase: an elongation or enlargement of the receptacle that supports the carpels or nutlets, as in many species of the Boraginaceae
• Gynoecium: a collective term for the pistils of a flower (compare androecium)

  H

• Habit: the overall appearance of a plant
• Halophyte: a plant that can tolerate an abnormal amount of salt in the soil
• Hamate: hook-shaped, hooked at the tip
• Hastate: spear- or arrowhead-shaped with the basal lobes facing outward
• Helicoid: coiled spirally like a spring or a snail shell
• Heliotropic: the movement of plant parts in response to a light source
• Hemiparasite: a plant that derives its energy both from parasitism and from photosynthesis
• Herbaceous: fleshy-stemmed, not woody
• Heteromorphic: of one or more kind or form
• Heterostylous: having different kinds of style (and stamen) lengths
• Hexa-: a prefix meaning six
• Hibernal: flowering or appearing in the winter
• Hilum: a scar on a seed indicating its point of attachment
• Hip: a fleshy, berry-like fruit, as in some members of the Rosaceae
• Hirsute: pubescent with stiff, coarse hairs
• Hirtellous: pubescent with very small, coarse, stiff hairs
• Hispid: rough-haired
• Hoary: covered with white or gray, short, fine hairs
• Holosericeous: covered with fine, silky hairs
• Homomorphic: all of the same kind or form
• Hooked: abruptly curved at the tip
• Host: a plant providing nourishment to a parasite
• Humifuse: spreading along or over the ground
• Humistrate: lying on the ground
• Hyaline: thin, translucent or transparent
• Hydrophytic: adapted to growing in water
• Hypanthium: a cup-shaped enlargement of the receptacle, creation by the fusion of sepals, petals and stamens
• Hypogynous: with stamens, petals and sepals atteched below the ovary (compare epigynous)

  I

• Imbricate: overlapping, like shingles on a roof
• Imperfect: describes a flower that has stamens or pistils but not both
• Implicate: twisted together, intertwined
• Incised: cut, often deeply, usually irregularly, but seldom as much as one-half the distance to the midrib or base
• Included: not exserted or protruding beyond the surrounding organ
• Incumbent: a term referring to seeds in which the embronic root is wrapped around and lies adjacent to the back of one of the two cotylodons (compare accumbent)
• Indehiscent: not opening by itself, said of a seed pod (compare dehiscent)
• Indeterminate: describes an inflorescence in which the outer or lower flowers bloom first, allowing an indefinite elongation of the flowering stem (compare determinate)
• Indigenous: native to an area
• Indurate: hardened and/or stiffened
• Indusium: a scale-like outgrowth on a fern leaf which forms a covering for the sporangia
• Inferior ovary: one that is situated below the point of attachment of the sepals and petals, and possibly below the point of attachment of all other flower parts and embedded in the floral stem
• Inflexed: turned abruptly or bent inwards
• Inflorescence: the flowering portion of a plant
• Infra-: a prefix meaning below or beneath
• Inframedial: below the middle
• Infraspecific: below the species level
• Infundibular: funnel-shaped
• Innate: borne at the apex
• Inter-: a prefix meaning between or among
• Internode: the portion of a stem between two successive nodes
• Interrupted: not continuous, with gaps
• Introrse: turned or opening inward toward the axis as an anther toward the center of a flower (compare extrorse)
• Involucel: a secondary involucre as in the Apiaceae
• Involucre: a set of bracts subtending a flower or an inflorescence
• Involute: with both edges inrolled toward the midnerve on the upper surface (compare revolute)
• Irregular: describes a flower that is not radially symmetric, the similar parts of which are unequal in size or form

  J

• Joint: the point on a plant stem from which a leaf or leaf-bud grows, more commonly termed a node
• Jugate: with parts in pairs
• Junciform: rush-like in appearance

  K

• Keel: the two lower petals of most pea flowers, united or partially joined to form a structure similar to the keel of a boat

  L

• Labiate: lipped
• Lacerate: irregularly cut or cleft
• Laciniate: cut into slender lobes
• Lacunate: pitted
• Lacustrine: growing around lakes
• Laevigate: lustrous, shining
• Lanate: with long tangled wooly hairs
• Lanceolate: Significantly longer than wide and widest below the middle, gradually tapering toward the apex
• Lanulose: with very short hairs, minutely downy or wooly
• Lateral: borne at or on the side of
• Latifoliate: with broad leaves
• Leaflet: one segment of a compound leaf
• Legume: a dry, dehiscent fruit derived from a single carpel and usually opening along two lines of dehiscence like a pea pod
• Lemma: in grasses, the lower and usually larger of the two bracts of the floret
• Lepidote: covered with small scurfy scales
• Liana: a herbaceous or woody, usually perennial, climbing vine that roots in the ground and is characteristic especially of tropical forests
  
• Ligneous: woody
• Ligulate: (1) Describing a floral head in the Asteraceae that contains only ray flowers, or ligules; (2) strap-shaped
• Limb: the upper, expanded portion of a corolla which has fused petals
• Linear: long and narrow with sides that are parallel or nearly so
• Lineate: marked with parallel lines
• Lingulate: tongue-shaped
• Littoral: growing along the shore
• Livid: pale grayish-blue
• Lobe: usually a rounded segment of an organ
• Lobed: more or less deeply cut but not as far as the midrib
• Lobulate: with small lobes
• Locule: a cavity of the ovary which contains the ovules
• Loculicidal: said of a capsule, longitudinally dehiscent through the ovary wall at or near the center of each chamber or locule (compare poricidal, septicidal)
• Loment: a legume which is constricted between the seeds
• Lunate: crescent-shaped
• Lurid: pale brown to yellowish-brown
• Lutescent: yellowish
• Lyrate: lyre-shaped, pinnatifid with the terminal segment large and rounded and the lower lobes increasingly smaller toward the base
  

  M

• Machaerantheroid: having involucral bracts with recurved tips
• Macro-: prefix meaning large or long
• Macrophyllous: having large leaves
• Maculate: spotted or blotched
• Malacophyllous: with soft leaves
• Malvaceous: mallow-like
• Mammilate: with nipple-like protuberances
• Manicate: with a thick, interwoven pubescence
• Many: same as numerous, often used to describe the number of stamens on a flower and specifically meaning eleven or more
• Marcescent: withering but still persistent as with petals and sepals or the basal leaves of some plants
• Margin: the edge, as of a leaf blade
• Marginate: distinctly margined
• Matinal: blooming in the early morning
• Mauve: bluish or pinkish-purple
• Mealy: describing a surface that is covered with minute, usually rounded particles
• Mega-: prefix meaning large
• Membranous: thin, flexible and more or less translucent, like a membrane
• -merous: a suffix utilized to indicate the number of parts or divisions in a particular structure or organ, as in 4-merous or 4-parted
• Mesic: describes a habitat that is generally moist throughout the growing season (compare xeric)
• Meso-: prefix meaning middle
• Mesocarp: the middle layer of the pericarp of a fruit (compare endocarp, exocarp)
• Mesophytic: adapted to growing under medium or average conditions, especially relating to water supply
• Micro-: prefix meaning small
• Microphyllous: bearing small leaves
• Midrib: the main or central rib or vein of a leaf
• Monadelphous: having stamens with filaments united in a single group, bundle or tube
• Monandrous: with a single stamen
• Monanthous: one-flowered
• Mono-: prefix meaning one
• Monocotyledon: a plant having only one seed-leaf (compare dicotyledon)
• Monoecious: having both male and female flowers on the same plant (compare dioecious)
• Monotypic: describing a genus that contains only a single species
• Montane: of or pertaining to, or growing in, the mountains
• Mucilaginous: slimy and moist
• Mucronate: having a short projection at the tip, as of a leaf
• Multi-: prefix meaning many
• Multifid: cleft into very many narrow lobes or segments
• Multiflorus: many-flowered
• Multifoliate: bearing many leaves
• Muricate: rounded or roughened with short, hard or warty points
• Mycorrhizal: having a symbiotic relationship between a fungus and the root of a plant

  N

• Nacreous: having a pearly luster
• Napiform: turnip-shaped
• Nascent: in the process of being formed
• Natant: floating in water
• Navicular: boat-shaped
• Nectary: a plant part that secretes nectar, a sweet liquid that attracts bees, insects and birds
• Netted: same as reticulated, in the form or pattern of a network
• Neuter: lacking a pistil or stamens
• Nidulent: lying within a cavity, embedded within a pulp
• Nigrescent: blackish
• Nitid: lustrous, shining
• Niveous: white
• Nodding: hanging down
• Node: a point on a stem where leaves or branches originate
• Nodose: knobby or knotty
• Nomophilous: growing in or loving pastures
• Notate: marked with lines or spots
• Numerous: eleven or more, same as 'many'
• Nut: a dry, usually one-seeded, indehiscent fruit with a hard-walled exterior
• Nutant: nodding, drooping
• Nutlet: a small nut or one of the sections of the mature ovary of some members of the Boraginaceae, Verbenaceae or Lamiaceae
• Nyctanthous: night-flowering
• Nyctagimous: opening at night
  
  

• O

• Ob-: prefix signifying inversion or reversal of normal direction
• Obconic: inversely cone-shaped and attached at the pointed end
• Obcordate: inversely heart-shaped, attached at the point
• Oblanceolate: inversely lanceolate
• Obligate: restricted to particular conditions or circumstances
• Oblique: with sides unequal, usually describing the base of a leaf
• Oblong: two to four times longer than broad with nearly parallel sides, but broader than 'linear'
• Obovate: inversely ovate
• Obtuse: blunt or rounded at the apex
• Obverse: describing a leaf that is narrower at the base than at the apex
• Obvolute: a vernation in which two leaves are overlapping in the bud in such a manner that one-half of each is external and the other half is internal, i.e. each leaf both overlaps the next and is in turn overlapped by the one before
• Ocrea (pl. ocreae): a sheath around the stem derived from the leaf stipules, primarily used in the Polygonaceae
• Ochreoleucous: yellowish-white, cream-colored
• Octo-: prefix meaning eight
• Odd-pinnate: describing a pinnately-compound leaf with a single terminal leaflet (compare even-pinnate)
• Oligomeris: with less than the typical number of parts
• Oligophyllous: with few leaves
• Olivaceous: olive-green
• Open: uncongested, usually describing the organization of flowers in an inflorescence (compare dense)
• Opposite: describing leaves that are situated in pairs at each node along an axis
• Orbicular: circular
• Ornithophillous: bird-pollinated
• Orophilous: growing in or preferring mountain areas
• Oval: broadly elliptic, the width over half the length
• Ovary: the basal portion of a pistil where female germ cells develop into seeds after germination
• Ovate: egg-shaped, wider below the middle
• Ovoid: an egg-shaped solid
• Ovule: the structure that develops into the seed inside the ovary

  P

• Pachyphyllous: with thick leaves
• Palate: an appendage or raised area on the lower lip of the corolla which partially blocks the throat
• Palea: in grasses, the upper and generally smaller of the two bracts of the floret
• Pallid: pale
• Palmate: radiating from a single point like the spreading fingers of an outstretched hand
• Palmatifid: palmately cleft or lobed
• Paludose: growing in wet meadows or marshes
• Palustrine: same as paludose
• Pandurate: fiddle-shaped
• Panicle: a compound inflorescence in which the branches are racemose and the flowers are pedicelled on the branches
• Pannose: with a covering of short, dense, felty or wooly tomentum
• Papilionaceous: describing the structure of a corolla typical of the Fabaceae with banner, wings and keel
• Pappose: pappus-bearing
• Pappus: collectively, the bristles, hairs or scales at the apex of an achene in the Asteraceae
• Parasite: a plant which derives most or all of its food from another organisim to which it attaches itself
• Parietal: attached to the wall of the ovary instead of the axis
• Parted: lobed or cut in over half-way and often very close to the base or midrib
• Pectinate: describing a pinnatifid leaf whose segments are narrow and arranged like the teeth of a comb
• Pedicel: the stalk of a single flower that is part of an inflorescence
• Peduncle: the stalk of a flower cluster, or of a solitary flower not associated with others in an inflorescence
• Peltate: a type of leaf having its petiole attached to the center of the lower surface of the blade
• Pendent: hanging downward or drooping
• Penicillate: with a tuft of short hairs at the end, like a brush
• Penta-: prefix meaning five
• Pepo: a fleshy, indehiscent fruit with a hard, more or less thickened rind and a single many-seeded locule, characteristic of the Cucurbitaceae
• Perennial: a plant living for more than two years
• Perfect: containing both stamens and pistils
• Perfoliate: the stem apparently piercing the leaf or surrounded by basally joined opposite leaves
• Perianth: a collective term for the calyx and corolla
• Pericarp: the outer wall of mature fruit
• Perigynous: situated around but not attached to the ovary directly, describing a flower whose stamens and pistils are joined to the calyx tube and the ovary is superior
• Persicicolor: peach-colored
• Persistent: remaining attached after the usual time of falling
• Petal: a single segment of a divided corolla
• Petaloid: having the appearance of a petal
• Petiole: the stalk of a leaf
• Phloem: the food conducting tissue of vascular plants, bark
• Phreatophyte: a perennial plant that has deep and extensive root systems that enable it to tap underground sources of water
• Phyllary: one of the bracts below the flowerhead in the Asteraceae
• Phytolaccaceae: pokeweed family
• Pilose: having long, soft, straight hairs
• Pinnate: with separate segments which are arranged feather-like on either side of a common axis
• Pinnatifid: so deeply cleft or cut as to appear pinnate
• Pisaceous: pea-green
• Pistil: the central reproductive organ of a flower, consisting of ovary, style and stigma
• Pistillate: a female flower that has two or more pistils but no functional stamens
• Planoconvex: flat on one side and rounded on the other
• Plicate: folded like the pleats of a curtain
• Plumbeous: lead-colored
• Plumose: appearing plumelike or feathery from fine hairs that line two sides of a central axis
• Poly-: prefix meaning many
• Polyandrous: with many stamens
• Polyanthous: with many flowers
• Polycephalous: with many flower heads
• Polygamous: having both unisexual and bisexual flowers on the same plant
• Pome: a fleshy indehiscent fruit derived from an inferior, compound ovary and consisting of a modified floral tube surrounding a core with several seeds, such as an apple
• Poricidal: opening by pores, like a poppy capsule (compare loculicidal, septicidal)
• Posterior: on the side next to the axis (compare anterior)
• Prickle: a superficial, sharp-pointed outgrowth of the bark or epidermis of a plant
• Primocane: the first-year (usually flowerless) cane or shoots of Rubus (compare floricane)
• Procumbent: lying flat or trailing but not rooting at the nodes
• Prostrate: lying flat
• Protandrous: describing a plant in which the release of pollen precedes and does not overlap the period of stigma receptivity (compare protogynous)
• Protogynous: describing a plant in which stigma receptivity precedes and does not overlap the period of pollen release (compare protandrous)
• Proximal: nearest the axis or base (compare distal)
• Ptero-: prefix meaning winged
• Pterocarpous: with winged fruits
• Pterospermous: with winged seeds
• Puberulent: minutely pubescent
• Pubescent: covered with short, soft hairs
• Punctate: dotted or pitted, often with glands
• Pulverulent: dusty or chalky, as applied to the powdery coating on the stems and leaves of some plants
• Pulvinate: cushion- or mat-like
• Punctate: dotted with pits or with translucent, sunken glands, or with colored dots
• Puniceous: crimson-colored
• Purpurescent: becoming purplish
• Pyriform: pear-shaped

  Q

• Quadrate: square
• Quadri-: prefix meaning four
• Quinate: with five nearly similar structures from a common point
• Quinque-: prefix meaning five

  R

• Raceme: an elongate, unbranched inflorescence with pedicelled flowers on the main stem
• Racemose: raceme-like or bearing racemes
• Rachilla: a small rachis, in particular the axis of a grass spikelet
• Rachis: the main stalk of a flower cluster or of a compound leaf, also that part of a fern frond stem that bears the leaflets
• Radical: belonging to or proceeding from the root
• Radiate: describing a flower head in the Asteraceae that contains both ray and disk flowers
• Radicant: rooting from the stem
• Ramose: branching or branchy
• Rank: a vertical row usually of leaves or bracts that can be either opposite or alternate
• Receptacle: the expanded apex of a flower stalk which bears the floral organs, either such structures as individual petals, sepals etc., or entire flowers in head-like inflorescences such as is typical of the Asteraceae
• Recumbent: leaning or reposing upon the ground
• Recurved: curved backwards or outwards
• Reflexed: abruptly bent or curved downward
• Regular: describes a flower with petals or sepals all of equal size and shape, i.e. radially symmetrical or capable of being divided into mirror images on either side of any plane that passes through the center
• Reniform: kidney-shaped or rounded with a notch at the base
• Repand: with an undulating margin, less strongly wavy than 'sinuate'
• Repent: creeping
• Reticulate: having a netted pattern
• Retrorse: Bent backward or downward, reflexed (compare antrorse)
• Retuse: having a rounded apex with a shallow notch
• Revolute: having the margins inrolled toward the underside (compare convolute, involute)
• Rhizome: an underground stem capable of producing new stems or plants at its nodes
• Rhombic: with the shape of a diamond
• Rosette: a cluster of leaves in a circular arrangement at the base of a plant, often called the basal rosette
• Rostrate: having a beak or beak-like form
• Rotate: a rotate corolla is wheel-shaped with a short tube and a wide horizontally flaring limb
• Rotundifolius: with round leaves
• Rubescent: becoming red or reddish
• Rubiginous: rust-colored
• Ruderal: growing in disturbed habitats, weedy
• Rudiment: an imperfectly developed organ, a vestige
• Rufous: reddish-brown
• Rugose: wrinkled or bumpy
• Runcinate: sharply incised or pinnatifid with the segments facing backwards

  S

• Saccate: sac-shaped or pouch-shaped
• Sagittate: arrowhead-shaped, with two retrorse basal lobes
• Salient: projecting outward
• Salverform: with a slender tube abruptly expanded into a rotate limb
• Samara: dry fruit with wings that do not open when mature, as in maple trees
• Sanguineous: blood-red
• Sapid: with an agreeable taste
• Saponaceous: soapy
• Saprophytic: Deriving food from dead or decaying organic material in the soil and usually lacking in chlorophyll
• Sarcocaulis: with fleshy stems
• Saxatile: growing among rocks or in rocky, arid situations
• Scaberulent: slightly scabrous
• Scabrous: rough to the touch
• Scalariform: ladder-like
• Scale: a greatly reduced leaf or other outgrowth on a plant surface
• Scandent: climbing
• Scape: a leafless flowering stem arising directly from the ground
• Scarify: to roughen, score or scrape the hard, outer coating of a seed to assist in the absorption of moisture before germination, a process that many desert wash seeds require
• Scarious: thin, dry, membranous and more or less translucent
• Scissile: splitting easily
• Sclerophyllous: with stiff, firm leaves
• Scorpioid: describing a coiled inflorescence
• Scurfy: covered with small scale-like or bran-like particles or projections
• Sebaceous: tallowy or fatty
• Secund: Borne from only one side of an axis
• Semi-: prefix meaning half
• Sepal: a single segment of a divided calyx
• Septate: divided by one or more partitions
• Septicidal: said of a capsule, longitudinally dehiscent through the ovary wall at or near the center of each septa, preserving each locule as an intact entity (compare loculicidal, poricidal)
• Septum: any kind of a partition, specifically the wall between chambers in a compound ovary
• Seriate: arranged in rows or series
• Sericeous: covered with long, soft, straight, appressed hairs giving a silky appearance
• Serpentine: refers to soils that are low in calcium and high in magnesium and iron, derived from greenish or gray-green rocks that are essentially magnesium silicate, other characteristics of which are a high nickel and chromium content, and a low content of nutrients such as nitrogen
• Serrate: having sharp, forward-pointing teeth on the margin
• Serrulate: serrate with very small teeth
• Sessile: attached directly and without a petiole, pedicel or other type of stalk, said of either leaves or flowers
• Setaceous: bristle-like
• Setose: covered with bristles
• Sheath: a leafy, tubular structure usually on a sedge or grass that envelopes the stem
• Shrub: a small, woody plant with several stems
• Sigmoid: double-curved, S-shaped
• Silicle: a fruit similar to a silique, but much shorter, not much longer than wide
• Silique: a type of capsule found in the Brassicaceae, either half of which peels away from a central, transparent, dividing membrane
• Simple: a leaf that has one part, not subdivided into leaflets
• Sinistrorse: turned to the left or spirally arranged to the left (compare dextrorse)
• Sinuate: strongly or deeply wavy, usually referring to a leaf margin
• Sinus: the space or division, usually on a leaf, between two lobes or teeth
• Sori: clusters of spore sacs on a fern frond (singular: sorus)
• Sp: abbreviation for 'species'
• Spadix: a floral spike or head in which the flowers are borne on a fleshy axis
• Spathe: a large bract or pair of bracts subtending and usually partially enclosing an inflorescence
• Spatulate: spoon-shaped, gradually widening to a rounded apex
• Specific epithet: the second part of a scientific name which identifies the species
• Spicule: a short, pointed, epidermal projection
• Spike: an elongated, unbranched inflorescence with sessile or nearly-sessile flowers
• Spikelet: in grasses, the smallest aggregation of florets plus any subtending glumes
• Spine: a sharp-pointed rigid structure, usually a highly modified leaf or stipule
• Spinescent: bearing a spine or spine-like point
• Spinose: having a stiff and tough acuminate tip
• Spinulose: bearing very small spines
• Sporangium: a spore-case or sac in which spores are produced in a fern
• Spp: abbreviation for the plural of 'species'
• Spumose: foamy or frothy
• Spur: a hollow extension of a petal or sepal such as characterizes the larkspurs, and which often produces nectar
• Squamate: having or producing scales
• Squarrose: having spreading, recurved tips
• Ssp: abbreviation for 'subspecies'
• Stamen: the male or pollen-bearing organ of a flower, composed of filament and anthers
• Staminate: describing a male flower that contains one or more stamens but no functional pistils
• Staminode: a sterile stamen or other nonfunctional structure occupying the position and having the overall appearance of a stamen
• Standard: also called a banner, this is the upper petal or segment of a papilionaceous flower
• Stellate: starlike, with radiating branches and often referring to the pattern of hairs on the surface of a leaf
• Stem: the main upward-growing axis of a plant which bears the leaves and flowers
• Stenopetalous: with narrow petals
• Stenophyllous: with narrow leaves
• Stigma: the terminal portion of a pistil, which receives the pollen
• Stipe: that portion of a fern frond below the rachis, i.e. below where the leaflets are attached
• Stipitate: borne on a stipe or stalk
• Stipule: an appendage at the base of a petiole, usually in pairs
• Stolon: an elongated horizontal shoot above or below the ground, rooting at the nodes or apex
• Stomate: a small pore or opening on the surface of a leaf through which gaseous exchange takes place, i.e. the diffusion of carbon dioxide, oxygen and water vapor
• Stone: the hard, woody endocarp enclosing the seed of a drupe
• Stramineus: straw-colored
• Striate: with fine longitudinal lines or ridges
• Strict: very straight and upright
• Strigose: covered with rough, stiff, sharp hairs that are more or less parallel to a particular surface
• Strobilus: an inflorescence that is characterized by imbricated bracts or scales such as are borne on the ephedras
• Style: the narrowed portion of a pistil between and connecting the ovary and the stigma
• Sauveolent: fragrant
• Sub-: prefix meaning under, slightly, somewhat or almost
• Suberose/Suberous: corky-textured
• Subspecies: a group of plants within a species that has consistent, repeating, genetic and structural distinctions
• Subtend: to occupy a position below and adjacent to
• Subulate: awl-shaped
• Succulent: fleshy, juicy and thickened
• Suffruticose: low shrubby, with the lower part of the stem woody and the upper part herbaceous
• Suffused: tinted or tinged
• Sulcate: grooved or furrowed
• Sulfureous: sulfur-colored
• Summer annual: plant with seeds germinating in spring or early summer and completing flowering and fruiting in late summer or early fall (compare winter annual)
• Superior ovary: one that is located above the perianth and free of it
• Surcurrent: extending upward from the point of insertion, as a leaf base that extends up along the stem (compare decurrent)
• Surficial: growing near the ground, or spread over the surface of the ground
• Suture: a junction or seam of union, or a line of dehiscence
• Swale: a depression or shallow hollow in the ground, typically moist
• Sympatric: growing together with, or having the same range as
• Sympetalous: having the petals more or less united
• Syn-: prefix meaning united
• Synandrous: with united anthers
• Synoecious: having male and female flowers in the same flowerhead
• Synsepalous: having the sepals more or less united

  T

• Taproot: the primary root continuing the axis of the plant downward often quite deeply into the ground
• Tawny: tan in color
• Taxon: any group of plants occupying a particular hierarchical category, such as genus or species
• Tendril: a slender portion of a leaf or stem, modified for twining
• Tenuous: slender or thin
• Tepal: a collective term for sepals and petals, used when they cannot be easily differentiated
• Terete: circular in cross-section
• Terminal: at the end of the branch or stem
• Tesselate: checkered
• Ternate: in three's
• Tetra-: prefix meaning four
• Thorn: a short, stiff, sharp-pointed branch
• Throat: in some corollas with fused petals, the point of juncture between the tube and limb, a somewhat difficult point to distinguish
• Tiller: in grasses the young vegetative shoots
• Tomentose: wooly, with long, soft, matted hairs
• Toothed: having small lobes or points along the margin (as on a leaf)
• Tortuous: twisted or bent
• Transpiration: emission of water vapor from the leaves
• Transverse: at a right angle to the longitudinal axis of a structure
• Tri-: prefix meaning three
• Triad: a cluster of three, as spikelets of Hordeum or Hilaria
• Triandrous: having three stamens
• Trichome: a hair-like outgrowth from the epidermis
• Trichotomous: three-forked
• Trifid: three-cleft to about the middle
• Trifoliate: having three leaves
• Trifoliolate: having three leaflets
• Tripinnate: thrice divided
• Tropism: the turning of a plant part such as a leaf in response to some external stimuli
• Truncate: with a base or apex appearing as if cut straight across
• Tube: the lower or narrower portion of a corolla or calyx
• Tuber: a short, thickened underground stem which bears numerous buds
• Tubercle: a knoblike projection
• Tufted: in a dense cluster
• Tumescent: somewhat tumid, swelling
• Tumid: swollen
• Tunicate: having several concentric layers, such as in onions
• Turbinate: shaped like a top or inverted cone
• Twining: climbing by coiling around some support

  U

• Umbel: an inflorescence in which the flower stalks arise from a common point (in a compound umbel, this branching is repeated)
• Umbellet: a secondary umbel in a compound umbel
• Umbellulate: in the form of or having the appearance of an umbel
• Umbraculate: umbrella-shaped
• Unarmed: lacking thorns or prickles
• Uncinate: hooked near the apex or having the form of a hook
• Unctuous: greasy, oily
• Undulate: wavy
• Unguiculate: contracted at the base into a claw, as a petal
• Uni-: prefix meaning one
• Unilocular: having only a single locule in the ovary
• Uniseriate: arranged in one row or series
• Unisexual: bearing either stamens or pistils but not both
• United: describes petals that are fused together
• Urceolate: urn-shaped or pitcher-like, contracted at the mouth
• Urent: stinging
• Utricle: a small, thin-walled, single-seeded, more or less bladdery-inflated fruit
• Uva: a grape-like berry formed from a superior ovary

  V

• Vaginate: provided with or surrounded by a sheath
• Valvate: opening by valves or provided with valves
• Valve: one of the parts or segments into which a dehiscent fruit splits
• Varicose: swollen or enlarged in places
• Variegated: having a variety of colors
• Vascular: containing both xylem, the principal water and mineral-conducting tissue, and phloem, food conducting tissue
• Vein: the vascular portion of a leaf
• Velutinous: velvety
• Venation: the arrangement of veins in a leaf
• Ventral: on the inner or axis side of an organ or the upper surface of a leaf
• Ventricose: inflated or swollen unequally on one side
• Vermicular: worm-shaped or wormlike, or of worm-eaten appearance
• Vernal: appearing in the spring
• Vernation: the arrangement of leaves within a bud
• Vernicose: appearing as though varnished
• Verrucose: covered with wart-like projections
• Versatile: referring to an anther which attaches at or near its middle and is able to turn freely on its support (compare basifixed, dorsifixed)
• Versicolor: having various colors
• Verticillate: same as 'whorled'
• Vesicle: a bladder or cavity
• Vespertine: opening or functioning in the evening
• Villous: with fine, long, unmatted hairs
• Vinaceous: wine-colored
• Violaceous: violet-colored
• Virescent: becoming green or greenish
• Virgate: wand-like, as a straight, slender, erect stem
• Viscid: sticky or greasy
• Vitreous: transparent

  W

• Wanting: absent, lacking, nonexistent
• Weed: a troublesome or aggressive plant that intrudes where it is not wanted, especially a plant that vigorously colonizes disturbed areas
• Whorl: a circle of three or more structures radiating outward from the same node
• Wing: a thin, paperlike flat margin bordering or extending from a seed capsule, stem or flower
• Winter annual: plant with seeds germinating in late summer or fall and completing flowering and fruiting in spring or summer (compare summer annual)
• Woolly: having soft, woollike hairs

  X

• X: a symbol which when placed before a specific epithet indicates a hybrid of two species
• Xanthic: yellowish
• Xeric: pertaining to arid or desert conditions, implying a minimal water supply throughout most of the year (compare mesic)
• Xero-: prefix meaning dry
• Xerophytic: adapted to dry or arid conditions, places where fresh water is scarce or where water absorption is difficult due to an excess of dissolved salts
• Xylem: the water-conducting tissue of vascular plants
• Xylocarp: a hard, woody fruit such as the coconut

  Z

• Zonate: marked or colored in circular rings or zones
• Zoophilous: animal-pollinated
• Zygomorphic: with inequality in the size or form of similar parts, specifically bilaterally symmetric and capable of being bisected into equal mirror-image halves along one plane only