Glossary

A

abaxial: (adj) the side facing away from the axis, as in the underside of a leaf

abscission: (n) separating or falling off (as in, e.g., leaves)

acaulescent: (adj) having no stem or an extremely short stem, as in tufted or rosette plants

accrescent: (adj) continuing to grow after flowering

achene: (n) a dry, indehiscent, one-seeded fruit in which the seed is attached to the pericarp at a single point

acrogenous: (adj) growing only from the tip of the main stem

acropetal: (adj) exhibiting a pattern of growth or movement from the base of the stem to its apex

actinomorphic: (adj) of flowers, having radial symmetry; capable of being bisected into identifical halves along more than one axis

acuminate: (adj) tapering gradually to a point and forming more or less concave sides

acute: (adj) tapering to a sharp, pointed apex with more or less straight sides; broader than acuminate; forming an angle of less than 90 degrees

adaxial: (adj) pertaining to the side facing toward the axis, as in the upper surface of a leaf

adventitious: (adj) of an organ growing where it is not normally expected, e.g., roots growing from a stem

adventive: (adj) introduced, non-native, or added; introduced and naturalized

aerenchyma: (n) plant tissue with large, gas-filled intercellular spaces that facilitates gaseous exchange and maintains buoyancy

algae: (n) (sing. alga) photosynthetic, eukaryotic, unicellular or complex multicellular organisms, mainly aquatic, lacking true stems, roots, leaves, conducting vessels, and complex sex organs

alternate: (adj) (of leaves) bearing one leaf per node; placed singly on the stem at different heights

amphibious: (adj) of a plant able to live on land or in water

amphibious fluctuation-responder: (n) a plant that alters its growth pattern or morphology in response to the presence or absence of water

amplexicauline: (adj) (of leaf bases) clasping the stem

androecium: (n) the stamens collectively; the male parts of the flower

androphore: (n) a column or stalk on which the stamens are raised

angular: (adj) having projecting longitudinal angles; undulate, but sharply angled rather than gently rounded

anthela: (n) a type of cymose corymb inflorescence, in which the lateral flowers are higher than the central ones

anther: (n) the pollen-producing, apical part of the stamen

antheridium: male reproductive organ that produces gametes; a single cell in fungi and algae, multicellular in ferns, mosses, and vascular plants

anthesis: (n) the period from flower opening to fruit set

antrorse: (adj.) bent or directed upward or forward

apex: (n) the point farthest from the point of attachment; the tip (often pointed)

apical: (adj) of the apex

apiculate: (adj) having a small broad point at the apex

appendage: (n) a projecting part of a structure

appressed: (adj) pressed closely to or lying flat against

archegonium: (n) the female reproductive organ in mosses and ferns

aristate: (adj) (of a leaf) terminating in a stiff, bristle-like awn or tip

articulate: (adj) jointed; having well-defined joints or nodes at which separation occurs at maturity

attenuate: (adj) narrowing gradually to a point

auricle: (n) an ear-shaped lobe or appendage at the base of some leaves and flower petals

auriculate: (adj) bearing auricles

autogamous: (adj) self-fertilized

axil: (n) the angle between a leaf or branch and the stem or trunk from which it springs

axillary: (adj) in, of, or produced from an axil

axis: (n) the main stem; the central column of an inflorescence or other structure

B

basal: (adj) at or pertaining to the base, or point of attachment

bifurcate: (adj) split into two

bilabiate: (adj) two-lipped

bipinnate: (adj) twice pinnate; having both primary and secondary pinnate divisions

bisexual: (adj) having both male and female sexual reproductive structures on one individual or in one flower

bladder: (n) a hollow chamber designed for trapping or flotation, notably in bladderworts

bladderwort: (n) any plant of the genus Utricularia

blade: (n) (syn. lamina) the flat, expanded part of a leaf, frond, or petal (excluding, e.g., the petiole)

boreal: (adj) of a climatic zone bordering the Arctic

bract: (n) a modified leaf near a flower or inflorescence, often reduced, sometimes large and/or petaloid; also glumes, lemmas, and paleae of grass spikelets

bracteate: (adj) possessing or bearing bracts

bracteolate: (adj) possessing small bracts

bracteole: (n) a secondary bract, often very small

bud: (n) an embryonic meristem (dividing cell-mass) enclosed in small, protective scales, that develops into a flower, leaf or another stem

bulbil: (n) a small bulb-shaped body, usually produced for asexual reproduction

bullate: (adj) having a pimpled or blistered surface

C

caducous: (adj) falling off easily or at an early stage

calyculus: (n) a group of small bracts that resembles a calyx

calyx: (n) the outer whorl of the perianth; all the sepals of a flower

campanulate: (adj) bell-shaped

capillary: (adj) slender, hair-like

capitate: (adj) terminated by an enlarged and rounded head

carpel: (n) a unit of the gynoecium (female reproductive organ); consisting of a stigma, style, and ovary

caryopsis: (n) a dry, indehiscent, one-seeded fruit in which the seed coat is fused to the pericarp

cataphyll: (n) a reduced, small leaf resembling a scale

caulescent: (adj) having a more or less well developed above-ground stem

cauline: (adj) pertaining to or belonging to the stem

chromatophore: (n) one of the colored plastids in plant cells

ciliate: (adj) with a marginal fringe of stiff hairs

circumboreal: (adj) (of plants) found all around the world in the Northern Hemisphere

clavate: (adj) club-shaped; gradually widening toward the apex

claw: (n) narrowed base of some petals and sepals

cleistogamous: (adj) (of flowers) remaining closed, self-pollinating, and setting fertile seed

clone: (n) a plant produced by asexual reproduction, e.g., from cuttings

compound: (adj) with two or more like parts, as in a compound leaf; divided into two or more subsidiary parts or orders, as in a compound inflorescence

compound leaf: (n) a leaf divided into two or more leaflets

congruent: (adj) structurally identical in form and size

conical: (adj) perfectly cone-shaped

connate: (adj) of plant parts congenitally united into a single structure

connivent: (adj) coming into contact but not fused together

convolute: (adj) rolled up or rolled together longitudinally, as leaves or petals in bud

cordate: (adj) heart-shaped; in the form of two rounded lobes

coriaceous: (adj) thick, tough, leathery

corm: (n) a shortened, subterranean bulb-like stem or part of the stem, often bearing scale-like leaves

corolla: (n) the inner whorl(s) of the perianth; all the petals of a flower

corona: (n) a crown-like growth on the inside of the corolla

corymb: (n) a flat-topped or round-topped racemose inflorescence

cosmopolitan: (adj) essentially worldwide in distribution

costa: (n) midvein of leaf or pinna or rachis of pinnately compound leaf

cotyledon: (n) an embryonic leaf within or newly emerged from a seed

crenate: (adj) (of a margin) with shallow, rounded teeth

crown: (n) the basal portions of a herbaceous plant, usually where root or rhizome meets aerial stem

cucullate: (adj) hooded or hood-shaped

culm: (n) the stem of a grass or sedge

cuneate: (adj) wedge-shaped; triangular, with narrow end at the base

cuspidate: (adj) with a short, sharp, abrupt tip (cusp)

cylindrical: (adj) forming a nearly true cylinder

cyme: (n) a determinate, usually flat-topped or convex inflorescence in which the terminal flower blooms earliest

cymose: (adj) in the form of a cyme; bearing cymes

cypsela: (n) fruit typical of the Asteraceae, it develops from an inferior ovary and includes noncarpellary tissue (similar to an achene)

cystolith: (n) large intracellular structure formed by the deposition of lime on an ingrowth of the cell wall

D

deciduous: (adj) shedding of parts at the end of their growing period, as with leaves; those trees or shrubs that drop their leaves at the end of the season

decumbent: (adj) (of stems) having a portion lying along the ground, with upper parts erect or ascending

decurrent: (adj) extending downward, beyond the point of insertion

decussate: (adj) arranged along stem in pairs, with each pair at right angles to the pairs above and below

deflexed: (adj) bent abruptly downward

dehiscent: (adj) (of a fruit) splitting open at maturity to release contents

dentate: (adj) (of a leaf margin) (1) toothed; (2) bearing shallow teeth projecting outward from midrib

denticulate: (adj) minutely dentate; projecting in the form of a small tooth; slightly toothed

determinate: (adj) (of an inflorescence) with the terminal or central flower opening first, thus the main axis does not elongate further

dicotyledon: (n) one of the two classes of angiosperms usually characterized by: seeds with two seed leaves (cotyledons); flower parts in 4s or 5s (or multiples); leaves with non-parallel venation, root systems with taproots

didynamous: (adj) having two long stamens and two short stamens

dioecious: (adj) having separate male and female flowers on different individuals of the same species

dioicous: (adj) having male and female organs on different plants

disk floret: (n) any of the small tubular flowers at the center of the flower head of certain composite plants, such as in the Asteraceae

dissected: (adj) (of leaves) +/- deeply divided, cut, or lobed, including being compound

distichous: (adj) (of leaves or flowers) distinctly arranged in two ranks along an axis; leaves may be opposite or alternate

dorsal: (adj) (1) of the back of an organ or the side turned away from the axis (syn. abaxial) (compare ventral); (2) in thallose plants (e.g. liverworts); of the upper surface

dorsoventral: (adj) having or pertaining to both dorsal and ventral surfaces

drupe: (n) fleshy indehiscent fruit in which the seed or seeds are surrounded by a hardened endocarp (as in a cherry)

E

elliptical: (adj) in the form of an ellipse (oval)

emarginate: (adj) with a shallow notch at apex

embryo: (n) the developing immature plant (sporophyte) formed subsequent to fertilization, contained in the seed of flowering plants prior to germination and growth

embryotega: (n) an outgrowth of the seed coat, found in the family Commelinaceae

emergent: (adj) (syn. emersed) with parts raised out of the water; extending up out of the water

emersed: see emergent

endemic: (adj) restricted to a certain geographical location

endostome: (n) the inner portion of the peristome

entire: (adj) having a continuous margin that is not toothed or lobed

epicalyx: (n) a whorl of bracts outside the true calyx

epidermis: (n) the outer layer of cells on a plant structure

epilithic: (adj) growing on the surface of a rock

epipetalous: (adj) (of stamens) arising from the petals

epiphytic: (adj) of a plant growing on another plant but not parasitic; plant grown on may be alive or, e.g., a dead tree trunk

equitant: (adj) (of leaves) in two rows or ranks, overlapping and folded lengthwise, the whole effect fan-like as in the Iridaceae

excurrent: (adj) extending beyond the end of a leaf or pinna

exserted: (adj) projecting beyond, sticking out or protruding

F

falcate: (adj) shaped like a scythe or sickle

fenestration: (n) (of leaves) the pattern of windowed holes in a leaf lamina (occurring in some species of Aponogeton)

fertile: (adj) producing viable seed, spores, or pollen; capable of reproducing

fid: (suffix) deeply cut or lobed, e.g., 2-fid, 3-fid

filament: (n) the stalk of the stamen, which supports the anther

filiform: (adj) thread-like; long and thin

fimbriate: (adj) fringed with long hairs or processes

flabellate: (adj) fan-shaped; broadly wedge-shaped

floret: (n) one of the small individual flowers within a dense cluster of flowers, as in a compound inflorescence and in grass spikelets

frond: (n) (1) a term used to describe the leaves of, e.g., ferns, palms, or duckweeds; (2) a leaf-like organ (as in .e.g. some algae, such as Caulerpa)

fusiform: (adj) spindle-shaped, tapering at both ends

G

gametangium: (n) cell or organ that produces gametes

gametophyte: (n) the gamete-producing haploid phase in the plant life cycle; in some lower vascular plants it is multicellular and independent

gemma: (n) specialized multicellular unit of vegetative reproduction found in certain mosses and liverworts

geophytic: (adj) having underground storage organs, such as a bulb, tuber, corm, or rhizome

glabrescent: (adj) becoming hairless at maturity

glabrous: (adj) without hairs or scales

gland: (n) a secreting cell or group of cells on the surface of a plant structure

glaucous: (adj) covered with a waxy whitish or bluish coating

globose: (adj) spherical or nearly so

glochidium: (n) (pl. glochidia) a hair-like process bearing an anchor-like tip, that projects from the surface of microsporangial massulae in the Salviniaceae

gynandrous: (adj) with stamens (male reproductive unit) and pistils (female reproductive unit) fused into a column

gynoecium: (n) the female reproductive organs of a flower; collectively, all the carpels of a flower

H

halophytic: (adj) growing in saline conditions, such as a salt marsh, semi-desert, mangrove swamp, or seashore

hastate: (adj) (of a leaf) with a narrow, pointed lamina with two basal lobes spreading more or less at right angles to the petiole

head: (n) inflorescence consisting of small closely packed stalkless flowers or florets arising at the same level on a flattened axis; of several types, including: discoid (composed entirely of disk flowers) and radiate (composed of central disk flowers and marginal ray flowers)

helicoid: (adj) coiled like a spiral or helix

heterophyllous: (adj) with dissimilar leaves on the same plant; often occurs on plants with both submersed and emersed leaves

heterostylous: (adj) (of flowers) having styles differing in length, shape or number in flowers among various plants of one species

hibernaculum: (n) a winter-resting bud of scale-like, non-carnivorous leaves seen in Pinguicula

hispid: (adj) covered with firm, stiff hairs

hyaline: (adj) thin and translucent or transparent

hybrid: (n) a specimen produced by the sexual reproduction of two plants of different species or subspecies

hypanthium: (n) the cup-shaped structure formed from the fusion of the basal parts of the calyx, corolla, and stamens, on the rim of which these parts arise

I

imbricate: (adj) overlapping like shingles on a roof

imparipinnate: (n) a pinnate leaf in which all leaflets are paired and a terminal leaflet is present

indeterminate: (adj) 1) (of an inflorescence) with lower or outer flowers opening first, so that the main axis continues elongating; 2) unrestricted growth, as with an apical meristem capable of producing an unlimited number of lateral organs.

inflated: (adj) bladdery; swollen, or appearing so

inflexed: (adj) curved or bent inwards toward the axis

inflorescence: (n) the arrangement of flowers on the floral axis

internodal: (adj) of or pertaining to an internode

internode: (n) section of a stem between two nodes

involucre: (n) a whorl of bracts subtending a flower, flower cluster, or inflorescence

involute: (adj) rolled inwards (usually of leaves)

irregular: (adj) asymmetrical

K

keel: (n) a sharp crease or ridge

keeled: (adj) having a keel; sharply creased

L

labellum: (n) in orchids, a central petal at the base of the flower, typically larger than the other petals and of a different shape

lacerate: (adj) torn; irregularly cut or slashed

lacuna: (n) a cavity or depression

lamella: (n) a thin, plate-like layer

lamina: (n) the expanded portion of a leaf or petal

lanceolate: (adj) lance-shaped; widest point below the middle, tapering to the apex

lateral: (adj) on or pertaining to the side of an organ or structure

latex: (n) a usually milky-looking liquid found in the cells of many plants

leaflet: (n) one of the leaf-like units of a compound leaf

lignify: (v) to become woody

ligulate: (adj) possessing or with a ligule

ligule: (n) (1) a strap-shaped structure; (2) an often thin, membranous or hairy structure projecting from the top of the leaf sheath in grasses and a few other families; (3) the flattened part of the ray corolla in the Asteraceae

limb: (n) the expanded portion of a petal or bract (e.g., a spathe)

lithophyte: (n) plant that grows in or on rocks

lithophytic: (adj) growing in or on rocks

littoral: (adj) of or along the shore

lobed: (adj) divided into (usually rounded) segments

M

macroalgae: (n) (sing. macroalga) large algae; seaweeds

marcescent: (adj) withering but not falling off

margin: (n) edge; rim

massula: (n) (pl. massulae) in Azolla, a mucilaginous group of microspores within the microsporangium

megaphyll: (n) the type of leaf found in ferns, gymnosperms, and angiosperms having complex venation patterns

megaspore: (n) in plants that produce two different kinds of spores, the larger of the two types, which develops into the female gametophyte

megasporocarp: (n) a specialized structure containing megasporangia

mericarp: (n) a one-seeded section of a schizocarp, as in the fruits of Apiaceae

merous: suffix indicating the number of parts in a whorl

mesophytic: (adj) growing in an environment with a moderate amount of water

microphyll: (n) the type of leaf found in lower vascular plants such as mosses and horsetails, usually relatively small, with simple venation or a single vascular strand

microsporangium: (n) (pl. microsporangia) a saclike structure that produces microspores

microspore: (n) in plants that produce two different kinds of spores, the smaller of the two types, that develops into the male gametophyte

microsporocarp: (n) a specialized structure containing microsporangia

midrib: (n) the main or central vein, line or rib in a leaf or perianth segment

midvein: (n) the primary, usually central vein of a leaf or leaflet

moniliform: (adj) cylindrical and constricted at regular intervals; like a string of beads

monocarpic: (adj) flowering only once and then dying

monochasial: (adj) in the form of a monochasium

monochasium: (n) a cyme reduced to single flowers on each axis, resulting in a helicoid or scorpioid inflorescence

monocotyledon: (n) one of the two classes or angiosperms characterized by: seeds with one seed leaf (cotyledon); flower parts usually in 3s (or multiples); leaves often with parallel venation, root systems usually diffuse, usually lacking secondary growth; a plant classified in this class

monoecious: (adj) having separate male and female flowers on the same individual

monotypic: (adj) represented by a single example (species)

mucilage: (n) a gelatinous substance produced by many different types of plants and algae, on various structures, such as stems or leaves

mucro: (n) a short, sharp, abrupt point

mucronate: (adj) tipped with a mucro

N

nectary: (n) a specialized gland producing nectar

nerve: (n) a vein, line, or rib, usually indicating a strand of vascular tissue

nutlet: (n) a small nut

O

obcompressed: (adj) compressed or flattened at right angles to the primary axis, as back to front instead of side to side

oblanceolate: (adj) lance-shaped, with attachment at or near the narrow end. (compare lanceolate)

oblate: (adj) almost spherical but compressed at poles

oblique: (adj) (usually of leaf bases) having unequal sides; almost (but not quite) symmetrical

oblong: (adj) two to four times longer than wide, with +/- parallel sides

obovate: (adj) ovate, with the narrow end at the base

obtuse: (adj) with a blunt or rounded apex and sides coming together at an angle of more than 90 degrees

ocellus: (n) (pl. ocelli) an eye-like mark; a spot of color surrounded by another spot of color

ocrea: (n) a sheath or tube formed at the base of the petiole by two united stipules, as in some members of the family Polygonaceae

oogonium: (n) (pl. oogonia) the female reproductive organ in some algae and fungi, consisting of a large cell that produces female gametes

operculum: (n) a cap-like covering or lid on some flowers or fruits that becomes detached at maturity by abscission

opposite: (adj) (of leaves) two leaves per node; in pairs on opposite sides of an axis

orbicular: (adj) circular in outline

ovary: (n) a hollow organ at the base of the carpel of a flower in which ovules are produced

ovate: (adj) egg-shaped in outline; generally with the broad end at or near the base

ovoid: (adj) egg-shaped in three dimensions

ovule: (n) the embryonic seed

P

palea: (n) in grasses the distal bract subtending the floret; in composite flowers a scale-like bract that subtends an individual floret on the receptacle

palmate: (adj) (of leaves or venation) with lobes, leaflets, divisions or veins originating from the same point

paludarium: (n) type of vivarium (aquariam, terrarium) that incluces both terrestrial and aquatic organisms

pandurate: (adj) shaped like the body of a fiddle

panicle: (n) an indeterminate, branched (often much-branched) inflorescence; the ultimate units may be of a different inflorescence type

papilla: (n) (pl. papillae) a short, nipple-like protuberance

papillose: (adj) bearing papillae

pappus: (n) modified calyx in the Asteraceae, composed of hairs, bristles, awns, or scales

paripinnate: (n) a pinnate leaf in which all leaflets are paired and the terminal leaflet is absent

pedicel: (n) the stalk of a single flower in an inflorescence, or of a grass spikelet

pedicellate: (adj) borne on a pedicel

peduncle: (n) the stalk of a flower cluster or inflorescence

pedunculate: (adj) borne on or possessing a peduncle

peltate: (adj) of usually flat organs such as leaves: having its stalk attached to its underside away from the margin, near the center

percurrent: (adj) reaching to the tip of a leaf or pinna

perennial: (adj) (of a plant) having a life cycle of more than two years

perfect: (adj) (of a flower) having both functional male and female reproductive organs (stamens and pistils); bisexual

perfoliate: (adj) (of leaves) with base or margins completely surrounding stem

perianth: (n) collective term for the calyx and corolla of a flower; also used for floral whorl(s) in which the calyx and corolla cannot be resolved; any of the leaves or bracts surrounding the sex organs of bryophytes

pericarp: (n) fruit wall

pericladium: (n) the sheathing base of a leaf when it expands and surrounds the supporting branch

peristome: (n) in some mosses and fungi, teeth-like structures surrounding the mouth of the capsule

persistent: (adj) (of leaves etc,) remaining attached; not being dropped or falling off

petal: (n) one segment of the corolla

petaloid: (adj) resembling a petal in appearance

petiolate: (adj) relating to or in the form of a petiole; bearing petioles

petiole: (n) the stalk of a leaf

petiolulate: (adj) having petiolules

petiolule: (n) the stalk of a leaflet in a compound leaf

photosynthesis: (n) the process whereby sunlight is converted into energy by chlorophyll

phyllary: (n) an individual bract of the involucre in Asteracea flower heads

pin flower: (n) in a heterostylous plant, the flower type in which the style is long and the stamens are short

pinna: (n) one of the primary divisions or leaflets in a compound leaf or frond

pinnate: (adj) in the form of a feather; of, e.g., leaflets, lobes, or veins: arranged in two rows along an axis

pinnatifid: (adj) (of leaves) deeply pinnately lobed half way or more, but not reaching the midrib

pinnatisect: (adj) pinnately cut or lobed to the midrib

pinnule: (n) in Caulerpa, the individual leaflet-like frond segments

pistil: (n) the stigma, style, and ovary collectively; the female reproductive organs

pistillode: (n) a sterile pistil

pith: (n) spongy tissue in the center of a stem or root

plantlet: (n) a small, immature plant that develops into a larger plant

pleonanthic: (n) a plant that flowers and does not die after flowering

plumose: (adj) (of hairs or bristles) fine, feather-like

pneumatophore: (n) a specialized structure developed from the root in certain wetland plants , some mangroves) serving as a respiratory organ

pollination: (n) the process of fertilization whereby pollen is transferred from the stamen to the stigma; transfer can be effected by wind, insect, or other vector, depending on the species

pollinium: (n) coherent mass of pollen grains, typically transferred as a unit during pollination (seen in Orchidaceae)

polymorphic: (adj) displaying multiple forms (of, e.g., an organ) in one organism

propagule: (n) a sexual or vegetative structure, such as a seed, fruit, or spore, that is dispersed and serves as a means of propagation

prostrate: (adj) growing closely along the ground

prothallus: (n) the independent gametophyte generation found in ferns and other lower vascular plants

protogynous: (adj) having the female reproductive structures come to maturity before the male

proximate: (adj) next or nearest in space

pterate: (adj) (suffix) winged, e.g.: dipterate - 2-winged, tripterate - 3-winged

puberulent: (adj) minutely pubescent

pubescent: (adj) (1) covered with short, soft hairs; (2) bearing hairs

pyrenoid: (n) structure found in chloroplasts of many algae that is possibly involved with starch deposition

R

raceme: (n) an indeterminate, unbranched inflorescence having pedicelled flowers on a usually elongated axis (may be cymose)

racemose: (adj) (1) bearing racemes; in the form of a raceme; (2) raceme-like

rachis: (n) the main axis of, e.g., a compound leaf or an inflorescence

radical: (adj) (of leaves) proceeding from the root, as in basal leaves clustered at the base of the stem

ray floret: (n) a pistillate or sterile zygomorphic flower with a flat part of its corolla (ray), found in the inflorescence (head) of many plants in the Asteraceae

receptacle: (n) the portion of the pedicel on which the flowers are borne, or in the Asteraceae, the portion of the peduncule upon which the florets of the head are borne

recurved: (adj) curved downward or backward

reflexed: (adj) abruptly curved or bent downward

regular: (adj) uniform in shape or structure; radially symmetrical and parts similar in size and arrangement

reniform: (adj) kidney-shaped

reticulate: (adj) in the form of a network; netted (often of leaf veins)

retrorse: (adj) bent backward or downward

rheophyte: (n) an aquatic plant that can live in fast-moving water currents

rheophytic: (adj) living or able to live in fast-moving water currents

rhizoid: (n) a root- or root hair-like structure lacking vascular tissue

rhizomatous: (adj) possessing rhizomes

rhizome: (n) an underground stem, usually growing horizontally, from which both roots and shoots emerge directly; the thick, above-ground stem of ferns

rhizophore: (n) any of the leafless branches that arise from the stem at points of forking, growing toward the soil (seen in Selaginella)

rib: (n) a leaf vein; a ridge of plant-tissue thicker than its surrounding blade, often vascularized

riparian: (adj) growing by rivers or streams; of, adjacent to, or living on, the banks of a river, lake, pond, etc.

riparium: (n) a type of aquarium that simulates wet habitats found along the edges of lakes, rivers, ponds and streams

rosette: (n) a radiating cluster of leaves, usually close to the ground at the base of a plant

rostellum: (n) flap of tissue extending from the stigma lobe that projects in front of the anther to separate the two (seen in Orchidaceae)

rugose: (adj) wrinkled

runner: (n) a specialized stolon that develops from axil of a leaf at the crown of the plant, has long internodes, and grows horizontally, forming shoots and roots at some nodes

S

saccate: (adj) in the shape of a bag or pouch

sagittate: (adj) shaped like an arrowhead

scabrous: (adj) of a surface, rough to the touch due to presence of short stiff hairs

scale: (n) any thin, usually small and dry, membranous to leathery bract

scape: (n) a leafless flowering stalk arising from ground level in acaulescent plants

scarious: (adj) dry, thin, membranous, non-green, more or less translucent

senesce: (v) to deteriorate with age

sepal: (n) a member of the outer envelope of a flower (calyx)

septate: (adj) divided or partitioned by cross-walls

serrate: (adj) (of a leaf margin) bearing sharp teeth pointing forward or to the apex

serrulate: (adj) minutely serrate

sessile: (adj) attached directly, without a stalk

setose: (adj) bristly; terminating gradually in a fine sharp bristle

sheathing leaf base: (n) a leaf base or petiole that surrounds a stem, partly or completely

sinus: (n) the indentation or space between two lobes or divisions

spadix: (n) a spike of small flowers borne on a thick, fleshy axis

spathe: (n) a large bract or bracts subtending and often enclosing an inflorescence

spathulate: (adj) (or spatulate) spoon-shaped

specific: (adj) pertaining to a species

spheroid: (adj) spherical with slightly flattened ends

spike: (n) an indeterminate, unbranching inflorescence of sessile flowers or flower clusters on a usually elongated axis

spikelet: (n) a small spike; basic unit of the grass and sedge inflorescence, commonly consisting of one to many florets (small flowers) subtended by bracts

spinose: (adj) bearing spines

sporangium: (n) (pl. sporangia) a unicellular or multicellular sac or structure that produces spores

sporocarp: (n) in some ferns and fungi, a hard, multicellular, nutlike receptacle which contains sporangia

sporophyll: (n) modified leaf that bears the sporangia

spur: (n) a usually slender, hollow projection formed by the fused bases of the lower petals in some flowers notably of the genus Utricularia; a sac-like projection or extension of a petal or sepal; a short, fruit-bearing stalk

stamen: (n) the male reproductive organ in a flower, consisting of a pollen-bearing anther and a filament

staminate: (adj) (of flowers) male; bearing stamens but not pistils

staminode: (n) a sterile stamen, not producing pollen; may be inconspicuous, petaloid, or showy

stem plant: (n) (a term used in the aquarium and pond plant trade) having an elongate stem (as opposed to a compact stem)

sterile: (adj) lacking male and/or female reproductive parts; not producing fruit, seed, pollen, spores, etc.

stigma: (n) the portion of the pistil that is receptive to pollen

stipe: (n) stalk supporting leaf or leaf-like organ

stipel: (n) a small, stipule-like structure at the base of a leaflet

stipitate: (adj) borne on a stipe or stalk

stipule: (n) one or a pair of appendages that sometimes develop at the base of a leaf; may be leaf-like, scarious, or spine-like

stipulode: (n) a one-celled structure arrayed in one or more rows subtending the branchlets in Chara

stolon: (n) an above-ground stem growing more or less horizontally and often forming adventitious roots at the nodes

stramineous: (adj) straw-like in color or texture

strigillose: (adj) minutely strigose

strigose: (adj) with stiff, straight, sharp, appressed hairs

strobilus: (n) a well defined group of closely packed sporophylls bearing sporangia arranged around a central axis

style: (n) in a flower, the narrow and elongated part of the pistil between the stigma and the ovary

sub-: a prefix meaning slightly, somewhat, or nearly (used with a descriptive term); or meaning below (used with an anatomical term)

submerged: (adj) (syn. submersed) under water; submerged below the water surface

submersed: see submerged

subtend: (v) to be situated directly beneath an organ or structure, as bracts beneath an inflorescence

subulate: (adj) awl-shaped; tapering from base to apex

sympodial: (adj) a type of branching in which the main stem branches into successive repeated dichotomous branches

T

temperate: (adj) of the climatic zone between boreal and tropical

tendril: (n) a slender leafless shoot produced by many climbing plants as an aid to climbing

tepal: (n) a member of the perianth, when it cannot be differentiated into a calyx and corolla; used primarily for monocot flowers

terete: (adj) +/- circular in cross section

terminal: (adj) at the apex

ternate: (adj) in threes

terrestrial: (adj) growing on land as opposed to living in water

thalloid: (adj) (1) having a plant body not differentiated into roots, stems, and leaves (a thallus); (2) thallus-like

thallus: (n) a photosynthetic plant body that is not (or apparently not) differentiated into stems, roots, and leaves

thecae: (n) the pollen sac of an anther

thrum flower: (n) in a heterostylous plant, one of the flower types in which the style is short and the stamens are long

thyrse: (n) inflorescence in which the main axis is racemose and the secondary axes are cymose

tomentose: (adj) covered in dense, matted, wooly hairs

trap: (n) a plant structure designed to catch and detain animal prey

trichome: (n) an epidermal outgrowth such as a hair or scale

trichotomous: (adj) branching regularly into three parts or divisions

tridentate: (adj) three-toothed

trigger hair: (n) a specialized structure, found in the traps of Dionaea (Venus fly-trap) and Aldrovanda, which causes the trap to activate in response to stimulation

trigone: (n) a thickened area where three or more plant cells come together

trigonous: (adj) three-angled

trilete: (adj) of spores, having three scar lines forming a Y, or basically tetrahedral

tristichous: (adj) in three vertical rows

truncate: (adj) terminating abruptly, as if cut straight across

tuber: (n) un underground storage organ formed from swelling of a stem

tubercle: (n) a small, warty, or rounded swelling, nodule, or projection

tuberculate: (adj) bearing tubercles

tubular: (adj) (of a corolla, perianth, calyx tube or other structure) (1) tube-shaped; cylindrical: narrow and elongate with more or less straight sides; (2) having segments fused into a tube (of any shape)

tubulose: (adj) consisting of or resembling small tubes

turion: (n) a hibernating bud produced by certain aquatic plants from which growth emerges in the following spring

U

umbel: (n) a flat to convex inflorescence in which the flower pedicels (called rays) all arise from the same point

undulate: (adj) (of, e.g., a margin) with a wavy surface; wavy in the vertical (up and down) plane

unisexual: (adj) (of a flower) with either stamens (male) or pistils (female) but not both; consisting of only male or female flowers

urceolate: (adj) urn-shaped

V

vacuolated: (adj) having a vacuole or vacuoles

vacuole: (n) a clear, fluid-filled cavity in a cell

vegetative: (adj) (1) pertaining to or to the growth of plant organs or plant parts that have nonreproductive functions, such as leaves, roots, stems, etc.; (2) concering non sexual propagules such as tubers, turions, stem fragments, root crowns, rhizomes

velum: (n) a membranous, protective flap covering the sporangium (as in Isoetes)

venation: (n) the arrangement of veins in a leaf

ventral: (adj) of the front of an organ or the side facing or nearest the axis (syn. adaxial) (compare dorsal); upper surface

verticil: (n) (1) a whorl; a whorled arrangement of parts around an axis, as in a flower; (2) an inflorescence where the flowers are borne in whorls at separate intervals along the stem

verticillate: (adj) borne in verticils

vesicle: (n) a bladder or other hollow structure aiding flotation

villous: (adj) pubescent with long and soft hairs that are not interwoven

W

whorl: (n) three or more similar organs arranged in a circle at the same point around an axis

whorled: (n) bearing whorls; a type of leaf arrangement (phyllotaxis) in which leaves are in whorls

Z

zoospore: (n) an asexual spore produced by certain algae

zygomorphic: (adj) bilaterally symmetrical; symmetrical along only one plane