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Aquatic and Wetland Vascular Plants of the Northern Great Plains

Glossary of Botanical Terms


[ A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z ]

A

Abaxial:
See dorsal.
Acaulescent:
Appearing stemless, with leaves and flowers or inflorescences arising directly from the plant base.
Accrescent:
Increasing in size with age, often describing a calyx that expands as the fruit matures.
Achene:
A small, dry, indehiscent, single-seeded fruit in which the seed coat is separate from the ovary wall.
Achlorophyllous:
Lacking chlorophyll and thus nongreen.
Acuminate:
Tapering to a slender point.
Acute:
Forming an acute angle at either the tip or base.
Adaxial:
See ventral.
Adnate:
Fused to a different structure as when stamens are attached to petals.
Aggregate:
Clustered together.
Anastomosing:
Branching and rejoining.
Androgynous:
Describing an inflorescence of imperfect flowers in which the male flowers are borne above the female flowers.
Annulus:
A row of thick-walled cells in the walls of a sporangium that shrink or expand with changes in moisture to cause rupture of the sporangium and release of the spores.
Anthesis:
Flowering time.
Antrorse:
Directed upward or forward toward the tip.
Apical:
Positioned at the tip or apex of a structure.
Apiculate:
With a short, abrupt point at the tip.
Appressed:
Lying close to or parallel to an organ or surface.
Arcuate:
Moderately arched or curved.
Areolate:
With a surface divided into many angular sections.
Aril:
An outgrowth from the stalk (funiculus) of an ovule that partly or wholly encloses a seed.
Aristate:
Tapered to an awned or bristlelike tip.
Attenuate:
Very gradually tapered to a slender apex or base.
Auricle:
An earlikelobe or flap.
Auriculate:
With earlike lobes.
Awn:
A bristlelike projection, often arising from the tip of a structure.
Axil:
The angle between a stem and an attached leaf.
Axile:
Describing a placentation type in which ovules are attached where the septae intersect in the center of an ovary having two or more cells.
Axillary:
In the axil of a leaf or bract
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B

Barbellate:
Finely barbed.
Basal:
Arising from the base of the plant.
Berry:
A fleshy fruit containing few to many seeds
Bidentate:
With two teeth.
Bidentulate:
Slightly two-toothed.
Bifid:
Two-branched or lobed.
Bilabiate:
Two-lipped.
Bract:
A reduced or otherwise modified leaf that subtends a flower or inflorescence.
Bracteole:
A reduced bract, often secondary to larger, main bracts.
Bractlet:
A small secondary bract borne on a pedicel or hypanthium of a flower instead of below the pedicel.
Bulb:
A short, subterranean stem bearing fleshy, achlorophyllous scale leaves modified for food storage.
Bulbil (bulblet):
A small, secondary bulb that develops in a leaf axil, in an inflorescence or in another unusual position on the plant.
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C

Ca.:
Abbreviation for circa which means approximately.
Caducous:
Early deciduous.
Calcareous:
Describing soil or water with a high CaCO3 (lime) content.
Callus:
The thickened, sometimes pointed extension at the base of a grass floret where the lemma attaches to the rachilla.
Calyx:
The sepals of a flower collectively.
Campanulate:
Bell-shaped.
Canescent:
With dense, fine, whitish hairs that give the surface a gray, hairy appearance.
Capillary:
Very slender; hairlike or nearly so.
Capitate:
Headlike or borne in a head.
Capsule:
A dry, nonfleshy fruit containing few to many seeds, usually dehiscent at maturity.
Carpel:
In angiosperms, a modified ovule (seed)-bearing leaf, one or more of which make up a pistil. A simple pistil is comprised of one carpel, whereas a compound pistil is composed of two or more carpels fused together. The number of carpels making up a compound pistil is often indicated by: (1) the number of styles, style branches or stigma lobes; (2) the number of locules or placentae in the ovary; (3) the number of main sutures on a dehiscent fruit; or (4) the number of angles or lobes on the sides of the ovary.
Carpophore:
A slender stalk that supports the two mericarps (carpels) as they separate at maturity in fruits of the Apiaceae; an upward extension of the receptacle between the carpels.
Cartilaginous:
Firm but flexible, like cartilage in texture.
Catkin:
A soft, spikelike inflorescence of unisexual flowers typical of many trees and shrubs, often early deciduous.
Caudal:
Taillike.
Caudex:
A short, thickened, often woody, vertical or branched perennial stem, usually at or below ground level.
Caulescent:
With an above-ground, leafy stem.
Cauline:
Of the stem.
Cespitose:
Growing in tufts or dense clumps.
Chaffy:
Having the texture of the chaff (lemmas, paleas and glumes) removed from grain during harvesting or milling; or, in the Asteraceae, describing a receptacle (disk) that has chaffy bracts among the flowers.
Chartaceous:
Papery-textured and opaque.
Cilia:
Prominent hairs on a margin.
Ciliate:
Fringed with cilia.
Ciliolate:
Minutely ciliate.
Circinate:
Coiled in the bud, with the apex in the center of the coil, usually describing leaves that unfurl from a coil.
Circumscissile:
Describing a round fruit that dehisces horizontally so that the top portion comes off like a lid to release the seed or seeds.
Clasping:
Partly or completely surrounding the stem.
Clavate:
Club-shaped.
Claw:
The lower portion of a petal that is long and narrow toward the base and broadened toward the tip.
Cleft:
Cut into lobes.
Cleistogamous:
Descriptive of the flowers that remain closed in the bud or hidden in sheaths or bracts and are thus self-pollinated and fertilized.
Coma:
A ring or tuft of fine hairs on a seed, functional in wind dispersal.
Commissure:
A place where two similar parts adjoin.
Compressed:
Flattened.
Conduplicate:
Describing a leaf or modified leaf which is folded upward along the midrib.
Confluent:
Merging or blending of one part to another.
Conic:
Cone-shaped.
Connate:
Fused together along the margins.
Connivent:
Having margins closely adherent to those of an adjacent structure but without fusion.
Contorted:
Twisted or bent.
Convolute:
Descriptive of perianth parts or leaves which are rolled up and often twisted epically in the bud so that the margins of the perianth members or leaves successively overlap.
Cordate:
Heart-shaped at the base, with 2 rounded lobes.
Coriaceous:
Thick, tough and leathery.
Corm:
A short, fleshy, underground stem functioning in food storage, usually covered by papery-thin, modified leaves.
Cormose:
Having a corm.
Corniculate:
Having one or more small hornlike projections.
Corolla:
The petals of the flower collectively, especially when united.
Corrugated:
Irregularly folded or wrinkled.
Corymb:
A flat-topped or convex, racemose inflorescence.
Corymbiform:
Describing an inflorescence in which the flowers or flower heads are elevated to the same level on different branches so that the inflorescence or units of it appear flat-topped or convex.
Crenate:
With low, rounded teeth on the margin.
Crisped:
Irregularly curled or crinkled on the margin.
Cucullate:
With a blunt, hood-shaped tip.
Culm:
The stem of a grass or grasslike plant, especially one bearing an inflorescence.
Cuneate:
Tapered to an acute base.
Cupulate:
Cup-shaped.
Cuspidate:
With a terminal toothlike projection.
Cylindric(al):
Cylinder-shaped.
Cyme:
An inflorescence in which each flower is terminal, either on the main stem or a branch.
Cystolith:
An intercellular mineral deposit that accumulates in some of the epidermal cells of some plants.
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D

Deciduous:
Eventually falling off.
Decumbent:
Having the lower part of the stem lying along the ground, otherwise erect or ascending.
Decurrent:
Extending below the level of attachment as a wing or a ridge of tissue, e.g., as when a leaf is decurrent on a stem.
Decussate:
Describing opposite leaves that alternate at right angles to the pairs directly above and below them.
Dehiscent:
Splitting open or apart at maturity to release contents.
Deltate:
Broadly triangular.
Dentate:
Prominently toothed along the margin.
Denticulate:
Finely toothed along the margin.
Depressed:
Flattened or slightly indented on one end.
Diadelphous:
Describing stamens that are united by their filaments in two clusters, as in many legumes which have 9 stamens fused and one separate.
Dichotomous:
Forking or branching in pairs.
Didynamous:
Having 4 stamens that appear as two pairs of unequal length.
Diffuse:
Branched and widely spreading.
Dimorphic:
Having two different forms.
Dioecious:
Having male and female flowers borne on separate plants.
Distichous:
In two opposite rows.
Divaricate:
Widely spreading.
Divergent:
Spreading away from the main axis.
Dorsal:
Referring to the side of an organ oriented away from the main axis, e.g., the underside of a leaf or the outer surface or back side of an organ; abaxial.
Drupe:
A fleshy or fibrous, single-seeded fruit in which the seed is contained in a stony endocarp, e.g., a peach.
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E

Ebracteate:
Without bracts.
Eglandular:
Without glands.
Elater:
A winglike or straplike appendage on a spore adapted for wind dispersal.
Ellipsoid:
Describing a solid object which is elliptic in outline.
Elliptic(al):
In the shape of a flattened circle, more than twice as long as wide.
Emarginate:
Shallowly notched at the apex.
Emergent:
Growing upward above the water level.
Emersed:
Adapted to grow out of water.
Entire:
With a smooth margin.
Epigynous:
Describing a flower in which the ovary is inferior.
Epipetalous:
Describing stamens that are adnate by their filaments to the corolla.
Equitant:
Describing 2-ranked leaves that overlap at the base and have the blades sharply folded lengthwise so that they appear oriented edgewise toward the stem, e.g., the leaves of iris and gladiolus.
Erose:
With a thin, uneven or jagged margin.
Excurrent:
Extending beyond the tip or margin as a mucro or awn.
Exserted:
Extended beyond the mouth of an enclosing structure, as when stamens or styles project beyond the tip of a calyx or corolla.
Exstipulate:
Without stipules.
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F

Falcate:
Gently arched, sickle-shaped.
Farinose:
With a whitened, mealy-textured surface.
Fascicle:
A cluster arising from a common base.
Fibrillose:
Having small fibers.
Fibrous:
Having or containing fibers.
Filamentous:
Like a filament.
Filiform:
Threadlike.
Flabellate:
Fan-shaped.
Flexnous:
Wavy or sinuous.
Floral:
Of or pertaining to the flower.
Floret:
A flower greatly reduced in size as in the Asteraceae; in the Poaceae, the flower (or grain) and its enclosing lemma and palea.
Floriferous:
Flower-bearing.
Foliaceous:
Similar to the leaves or leaflets in shape, size, texture and/or color.
Follicle:
A unicarpellary fruit containing usually (1) few to several seeds and splitting open along one suture at maturity to release the seeds.
Fornix:
A small, arched scale. (pl. fornices)
Frond:
The leaf of a fern, or in Lemnaceae, a single thalloid segment of a colony.
Funnelform:
Funnel-shaped.
Fusiform:
Oblong and tapered at both ends.
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G

Gibbous:
Enlarged toward one side, usually at the base.
Glabrate:
Glabrous with age.
Glabrous:
Smooth, without hairs.
Glandular:
Containing or bearing glands, these sessile or stalked, often shiny and resinous in appearance.
Glaucous:
Whitish or bluish in color often due to a waxy coating.
Globose:
Spherical in shape.
Glomerulate:
With distinct, dense clusters.
Glomerules:
Small, dense clusters.
Glumes:
The two empty bracts at the base of a grass spikelet, the lowermost considered the first glume, the uppermost the second, seldom borne opposite each other, rarely absent.
Grain:
The fruit of almost all grasses, with the seed coat fused to the pericarp and the embryo positioned toward one side within the fruit; also termed caryopsis.
Gynaecandrous:
Describing an inflorescence of imperfect flowers in which the female flowers are borne above the male flowers.
Gynobasic:
Describing a style which is attached basally rather than terminally to the ovary.
Gynoecium:
The female portion of the flower, i.e., the carpels collectively.
Gynostegium:
A central column in a flower formed by fusion of stamens and pistil, characteristic of Asclepiadaceae and Orchidaceae.
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H

Haploid:
Containing only one set of chromosomes as a result of meiosis.
Hastate:
Descriptive of leaves having two divergent lobes at the base.
Hermaphroditic:
Having all perfect flowers.
Heterosporous:
Producing spores of two sizes, the larger giving rise to female gametophytes, the smaller to male gametophytes.
Hispid:
With long, stiff, straight hairs.
Hispidulous:
Somewhat or minutely hispid.
Hirsute:
With rather stiff spreading hairs.
Hirsutulous:
Minutely hirsute.
Homosporous:
Producing spores of all one size.
Hyaline:
Thin and translucent or transparent.
Hypanthium:
A floral disk, cup or tube extending from the receptacle to surround the ovary(ies) in perigynous and most epigynous flowers. The sepals, petals and stamens arise from the rim of the hypanthium.
Hypogynous:
Descriptive of flowers having the ovary(ies) superior and without a hypanthium.
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I

Imbricate:
Overlapping in rows like shingles on a roof
Imperfect:
Referring to flowers that are unisexual, i.e., having either functional stamens or pistil(s) but not both
Incised:
Deeply lobed or divided, but not completely divided into separate parts.
Indehiscent:
Not splitting open or apart at maturity, remaining whole and retaining the contents.
Indurate:
Hardened.
Indusium:
A membranous outgrowth of a fern leaf that wholly or partly covers a sorus.
Inflated:
Soft and swollen or expanded.
Inflexed:
Curved inward.
Inflorescence:
The flowers collectively and their arrangement on the plant.
Involucel:
An involucre of reduced bracts on secondary branches of a compound inflorescence.
Involucral:
Of the involucre.
Involucre:
One or more series of bracts that subtend a flower or inflorescence.
Involute:
Having the margins curled or rolled inward toward the upper surface.
Irregular:
Bilaterally symmetric so that the flower can be divided in half in only one plane to give two equal halves.
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L

Lacerate:
With an irregular, jagged margin, appearing as if torn.
Laciniate:
Deeply dissected into parallel, narrow segments.
Laminate:
With a flat blade.
Lanceolate:
Lance-shaped, broadest near the base, tapering to the tip and narrower than ovate.
Leaflet:
One of the leaflike segments of a compound leaf.
Legume:
The podlike fruit of most members of the mimosa, caesalpinia and legume families (Mimosaceae, Caesalpiniaceae and Fabaceae, respectively), derived from one carpel and usually dehiscent by two sutures.
Lemma:
The lower, larger bract that, together with the smaller palea, subtends and encloses the flower in grasses. The lemma, palea and their enclosed flower comprise the floret. The lemma is often awned from the tip or back.
Lenticels:
Blisterlike breaks in the epidermis of woody twigs. These develop to permit aeration of internal tissues.
Lenticular:
Lens-shaped.
Ligule:
In grasses and grasslike plants, a membranous or hairy extension arising from the inside of the leaf sheath at its juncture with the blade; a straplike structure; in the Asteraceae, the straplike corolla of a ray floret.
Linear:
Long, flat and narrow with parallel sides.
Locule:
A chamber or cell, usually inside an ovary.
Loculicidal:
Describing a capsule which splits open longitudinally to expose the locules of the ovary, each suture corresponding to the midrib of one of the carpels comprising the ovary.
Lyrate:
Lyre-shaped, with a large, rounded terminal lobe and smaller lateral lobes.
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M

Malpighiaceous:
Describing hairs which are centrally attached and tapered to two slender tips.
Mammillate:
With one or more nipplelike projections.
Marcescent:
Withering but remaining attached.
Membranous:
Thin, soft, flexible and usually translucent; like a membrane.
Mericarp:
One of the segments of a schizocarp.
Monadelphous:
Describing stamens that are united by their filaments often to form a sheath around the pistil.
Moniliform:
Like a string of loosely spaced beads.
Monoecious:
Having both male and female flowers on the same plant.
Mucro:
A short, sharp, abrupt, terminal point or awn.
Mucronate:
Having an abrupt, short-awned tip.
Mucronulate:
Minutely mucronate.
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N

Nerve:
A slender vein or rib of a leaf or other organ.
Node:
The point of attachment of a leaf or leaves to a stem.
Nodulose:
With small swollen joints or knots.
Nutlet:
Asmall nut, similar to an achene.
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O

Ob-:
A prefix meaning in a reversed direction, usually in reference to shape.
Oblique:
Slanted; or in the case of leaf blades and other flattened structures, having unequal sides or an asymmetrical base.
Oblong:
Much longer than wide with nearly parallel sides.
Obsolete:
Rudimentary, nearly absent.
Obtuse:
Shaped with an angle of greater than 90° at tip or base.
Ocrea:
A membranous sheath at nodes of the stem in the Polygonaceae, formed by fusion of the stipules. (pl. ocreae)
Olivaceous:
Olive-green.
Orbicular:
Round and flattened.
Ovate:
Flat and egg-shaped in outline; rounded at the base, broadest below the middle and often pointed at the tip.
Ovoid:
Egg-shaped.
Ovule:
The small, egg-shaped structure (megasporangium) containing the female gametophyte in seed-bearing plants. With maturation the ovule becomes a seed.
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P

Palate:
A raised portion of the lower lip of a sympetalous corolla that nearly closes the corolla tube.
Palea:
The uppermost or innermost of the two bracts (lemma and palea) that subtend and enclose the flower (or grain) in grasses.
Palmate:
Divergent or branched from a common point of attachment like the fingers on the hand.
Panicle:
A compound inflorescence in which flowers are borne on branches which themselves are branched, the entire inflorescence usually longer than broad; often used for any branched inflorescence of a grass or grasslike plant.
Papilla:
A small blunt projection arising from a flat surface. (pl. papillae)
Papillate (-ose):
Covered with short, blunt, cylindric projections.
Pappus:
The modified calyx of a composite flower that persists on top of the ovary or fruit as a series of bristles, scales or stiff awns.
Parietal:
Attached to the inner surface or wall of an enclosed structure such as an ovary.
Pectinate:
Having closely parallel, slender, toothlike projections like a comb.
Pedicel:
The stalk bearing a flower in an inflorescence.
Pedicellate:
Borne on a pedicel.
Peduncle:
The stalk of an inflorescence or a single flower if solitary.
Pedunculate:
Peduncled. Borne on a peduncle.
Peltate:
Describing a leaf or other flattened organ with the stalk attached at the center of the back side.
Pendulous:
Hanging downward from a support.
Perfect:
Describing flowers that have both stamens and pistil(s).
Perfoliate:
With the leaf base completely encircling the stem.
Perianth:
The floral envelope, consisting of the sepals and petals if both are present, or either of them if the other is absent.
Pericarp:
The mature fruit wall derived from the ovary wall, varying from dry and membranous or firm in dry fruit types to mostly fleshy and juicy in fleshy fruits.
Perigynium:
The saclike or scalelike structure that completely encloses the ovary (achene) in Carex.
Perigynous:
Descriptive of a flower that has a hypanthium surrounding, but not fused to or completely enclosing the ovary(ies).
Petal:
One of the innermost sterile appendages of the flower, usually soft-textured and colored; one member of the corolla.
Petaloid:
Petallike.
Petiolate:
With a petiole.
Petiole:
The stalk of a leaf.
Petiolule:
The stalk of a leaflet in a compound leaf.
Phyllode:
An expanded leaf which is actually bladeless and derived from a flattened petiole.
Phyllodial:
Describing leaves which are phyllodes.
Pilose:
With straight, spreading hairs.
Pinna:
A primary segment of a pinnately compound or lobed leaf. (pl. pinnae).
Pinnate:
Divided or branched with the parts attached in two opposite rows along a main axis, like the pinnae of a feather.
Pinnatifid:
Pinnately lobed but not divided all the way to the midrib.
Pinnatisect:
Pinnately dissected into narrow segments.
Pinnule:
The ultimate segment of a leaf that is pinnately divided two or more times.
Pistil:
The female unit of a flower, consisting of the ovule-containing ovary below and the pollen receptive stigma(s) above, these usually connected to each other by 1 or more slender styles. (See carpel.)
Pistillate:
Female, with functional pistil(s) only.
Plano-convex:
With one face flat and the other low-rounded.
Plicate:
With a series of longitudinal folds, like a fan.
Plumose:
Feathery due to soft spreading hairs.
Pollinium:
A waxy mass of pollen. (pl. pollinia)
Procumbent:
Prostrate and lying on the ground.
Pruinose:
With a heavy, waxy coating.
Puberulent:
Minutely pubescent.
Pubescence:
A covering of hairs.
Pubescent:
With hairs on the surface.
Pulverulent:
With very fine waxy granules on the surface.
Punctate:
Dotted, often with glands.
Puncticulate:
With tiny dots on the surface.
Pyriform:
Shaped like a candle flame.
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R

Raceme:
An inflorescence in which flowers are individually stalked along a main axis.
Rachilla:
The axis to which florets are attached in grasses and sedges, i.e., the main axis of a spikelet.
Rachis:
The main axis of an inflorescence or a pinnately compound leaf.
Ray:
In Asteraceae, the straplike corolla of a ligulate or ray floret; in Apiaceae, one of the primary branches of a compound umber.
Receptacle:
The terminal portion of a pedicel or 1-flowered peduncle to which the floral organs are attached. In Asteraceae, the disk on which the ray and/or disk florets are borne.
Recurved:
Curved downward or backward.
Reflexed:
Projecting downward.
Remote:
Widely separated.
Reniform:
Kidney-shaped.
Repand:
With a shallowly wavy margin.
Replum:
A persistent, membranous partition (placenta) that bears ovules on its margins and separates the two valves of the capsules in members of the mustard family (Brassicaceae).
Reticulate:
With a netlike pattern of markings or veins.
Retrorse:
Projecting backward or downward.
Retuse:
Having a notch in a rounded or obtuse apex.
Revolute:
Curled or rolled backward along the edges.
Rhizoid:
A nonvascularized, rootlike structure.
Rhizomatous:
Having rhizomes.
Rhizome:
A creeping underground stem often bearing scale leaves.
Rosette:
A cluster of leaves arising from a common point, usually the plant base.
Rotate:
Describing a corolla that has a short tubular portion and widely spreading lobes so that the whole corolla is saucer-shaped.
Rufous:
Reddish-brown.
Rugose:
With cross ridges or wrinkles.
Rugulose:
With a finely wrinkled surface.
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S

Saccate:
Sac-shaped.
Sagittate:
Arrowhead-shaped.
Salverform:
Trumpet-shaped, usually used to describe a sympetalous corolla with a slender tube and an abruptly flared limb.
Scaberulous:
Finely scabrous.
Scabrous:
Roughened with tiny toothlike or stiff, hairlike projections.
Scale:
A small, dry chaffy bract that subtends and often encloses a flower, especially characteristic of the Cyperaceae.
Scape:
A naked (leafless) or essentially naked stem that bears an inflorescence.
Scapose:
Descriptive of a leafless stem that bears an inflorescence or describing a plant that has a scape.
Scarious:
Thin, dry, nongreen and membranous in texture, like onion skin.
Schizocarp:
A dry fruit that breaks longitudinally into separate segments at maturity, each segment retaining the seed(s) and usually corresponding to one of the carpels comprising the ovary.
Scorpioid:
Coiled like a scorpion's tail.
Secund:
Having parts that appear to arise from only one side of an axis; often used to describe an inflorescence in which flowers are borne on one side of a stem or branch.
Sepal:
One of the outermost sterile appendages of the flower, normally enclosing the other floral parts in the bud; one member of the calyx.
Sepaloid:
Sepallike.
Septate:
Divided or partitioned into sections by cross walls.
Septicidal:
Describing a capsule which splits open along longitudinal sutures that correspond with where septae attach to the ovary wall.
Septum:
An internal partition; in an ovary, a longitudinal partition formed where adjacent carpels are united and dividing the ovary into cells. (pl. septae)
Sericeous:
With long silky hairs, these normally lying on the surface.
Serrate:
With toothed edges.
Serrulate:
With finely toothed edges.
Sessile:
Attached directly to a stem or other structure, lacking a stalk.
Setaceous:
Bristlelike.
Silique:
An elongate, usually terete capsule of the mustard family (Brassicaceae).
Simple:
Unbranched or undivided, usually in reference to stems or leaves.
Sinuate:
Wavy-margined.
Sinus:
The indentation or space between adjacent lobes or divisions of a structure such as a leaf or corolla.
Sorus:
A tiny cluster of sporangia borne on ferns. (pl. sort)
Spadix:
A thick, fleshy spike of small, densely crowded flowers.
Spathe:
One or two closely associated bracts that subtend a flower or inflorescence, characteristic of some monocots.
Spatulate:
Spatula-shaped, i.e., long and slender with a broadened tip.
Spike:
An unbranched inflorescence in which the flowers are all sessile on a main axis.
Spinulose:
With weakly spine-tipped projections.
Sporangium:
The spore-producing structure of a plant. (pl. sporangia)
Sporocarp:
A hard, nutlike structure that contains sporangia.
Spp.:
Abbreviation for the plural of species.
Spur:
A slender, tubular appendage extending backward from the base of a sepal or petal.
Stamen:
The male, pollen-producing organ of a flower, comprised of the anther and filament.
Staminate:
Male, with functional stamens only.
Staminode:
A reduced or otherwise modified, nonfunctional stamen.
Stigma:
The often sticky or finely hairy, pollen-receptive portion of the pistil, borne on the terminal portion of a style or sometimes sessile on the ovary.
Stipe:
A supporting stalk.
Stipitate:
Borne on a stalk or stipe.
Stipules:
A pair of appendages at the base of the petiole of some leaves that are membranous to foliaceous, minute to conspicuous, deciduous or persistent, sometimes fused together into one structure.
Stramineous:
Straw-colored.
Striate:
With fine longitudinal lines or nerves that run parallel.
Strigose:
With stiff hairs lying flat against the surface.
Strigulose:
Minutely strigose.
Stylopodium:
A swollen, disklikebase of a style, as in flowers of the Apiaceae.
Sub-:
A prefix meaning nearly or almost.
Submersed:
Adapted to grow or occur underwater; submerged.
Suborbicular:
Nearly circular.
Subtend:
Attached below and extending upward.
Subulate:
Awl-shaped.
Succulent:
Thick, fleshy and watery.
Superior:
Descriptive of an ovary or ovaries positioned on the surface of the receptacle and not embedded in other tissues.
Sympetalous:
Having the petals fused together.
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T

Taproot:
A root system with 1-few dominant vertical roots.
Tendril:
A threadlike, often branched appendage on a stem or leaf that coils around plants or other objects to provide support for a climbing plant.
Tepal:
A sepal or petal of a perianth in which the appendages are alike in size, shape, color and texture.
Terete:
Round in cross section, like the leaves of an onion.
Ternate:
Divided into three's.
Thallus:
A small, flattened plant body, often not differentiated into stems and leaves.
Thyrse:
A paniclelike inflorescence with one main indeterminate axis and many lateral axes which are determinate.
Tomentose:
With a felty covering of dense, woolly hairs.
Tomentulose:
Slightly tomentose.
Trichome:
An epidermal hair, scale or other outgrowth on a plant.
Trifid:
Divided into three branches or lobes.
Trigonous:
Three-sided and thus triangular in cross section.
Trimorphic:
Having three different forms.
Tripinnate:
Pinnately divided three times
Trullate:
Trowel-shaped.
Truncate:
Squared or leveled off at the base or tip.
Tuber:
A fleshy rhizome or portion of a rhizome that functions as a food storage organ, e.g., a potato.
Tubercle:
A small swelling, nodule or projection.
Tuberculate:
Having tubercles.
Tuberous:
Tuberlike, as in roots which are thick and fleshy.
Tufted:
Clumped, with stems clustered together at the base.
Turbinate:
Top-shaped.
Turion:
A specialized shoot or bud that overwinters to resume vegetative growth the following growing season, sometimes becoming detached from the parent plant to start a new plant.
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U

Umbel:
An inflorescence with several to many stalked flowers arising from a common point, like the stems of a candelabra.
Umbellet:
The small, secondary umber in a compound umber, as in most Apiaceae.
Umbelliform:
Like an umbel, umbel-shaped.
Undulate:
Wavy in an up and down fashion, vertically to the surface.
Urceolate:
Urn-shaped.
Utricle:
A small, 1-seeded fruit in which the pericarp is thin, dry and easily removed from the seed.
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V

Valve:
One segment of the wall of a dehiscent capsule, often corresponding to one of the carpels making up the ovary.
Ventral:
Adaxial; referring to the side of a structure oriented toward the main axis, e.g., the upper surface of a leaf or the inner surface of an organ.
Verticel:
One whorl, i.e., a group of leaves, bracts or flowers attached at the same level on a stem.
Verticillate:
Whorled in arrangement.
Vesicular:
Having one or more vesicles (saclike cavities).
Villous:
Covered with long, soft hairs.
Viscid:
Sticky.
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W

Whorled:
With three or more attached at the same level, usually in reference to leaves on a stem.
Winter bud:
A specialized vegetative bud or condensed, leafy shoot that overwinters to resume growth the following growing season.
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Previous Section -- Orchidaceae - The Orchid Family
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