|
prop root |
|
STRUCTURE |
|
A relatively stout adventitious root arising from the lower portion of a main stem and extending outward and downward toward the substrate, within which it ultimately becomes anchored, thus buttressing the aboveground portion of the plant. |
|
rhizoid |
|
STRUCTURE |
|
Any structure that is similar to a root in appearance and function but that is not a true root ontogenetically and anatomically, especially one produced from a gametophyte thallus. |
|
subsidiary cell |
|
STRUCTURE |
|
One of the cytologically distinctive epidermal cells that are sometimes present in a stomate and that surround and are regularly oriented in relation to the guard cells. |
|
bristle 2 |
= seta; > glochid, glochidium; < trichome |
STRUCTURE |
|
A trichome that is elongate, more or less straight, terete, fine-pointed, and stiff. |
|
blade |
= lamina |
STRUCTURE |
|
The expanded, more or less planate, distal portion, when present, of a leaf, leaflet or bract. |
|
neck (archegonial) |
|
STRUCTURE |
|
The distal narrowed portion of an archegonium above its bulbous base. |
|
dyad |
|
STRUCTURE |
|
A pair of coherent pollen grains shed as a unit. |
|
gemma pl. gemmae |
|
STRUCTURE |
|
A vegetative propagule by which a gametophyte reproduces asexually; produced by a process analogous to budding, from a more or less cupulate specialized area (gemmae cup) on the surface of the plant body (thallus); in Psilotophyta, Lycopodiophyta, Equisetophyta, Polypodiophyta. |
|
knee 2 |
|
STRUCTURE |
|
An emergent portion of an otherwise normally submerged secondary root of a wetland tree, resembling a bent human knee. |
|
pericarp |
|
STRUCTURE |
|
The portion of a fruit wall that is derived from the ovary wall; consisting of three more or less distinct tissue layers (exocarp or epicarp, mesocarp, and endocarp) that may or may not differ greatly in structure and/or function; the wall of a fruit, excluding any tissues of extra-ovarian (accessory) origin. |
|
vein |
= nerve; > costa, midnerve, midrib, midvein, rib |
STRUCTURE |
|
A strand belonging to any except the ultimate (least in diameter) order of vasculature in a leaf or other foliaceous structure. See also lateral vein, primary vein, secondary vein, tertiary vein, veinlet. |
|
mamma pl. mammae |
|
STRUCTURE |
|
A rounded-conoidal protrusion, resembling the breast of a mammal. |
|
testa pl. testae |
= seed coat |
STRUCTURE |
|
The outer protective layer of a seed, developed from the ovular integument(s). |
|
neck (floral tube) |
|
STRUCTURE |
|
The solid, usually constricted portion of a floral tube sometimes present between casing and collar when those are both present. |
|
cell 1 |
|
STRUCTURE |
|
Any of the basic structural/functional units that collectively or individually make up the various tissues of a plant; comprising, at least while physiologically active, a nucleus with included genetic material (chromosomes), a surrounding cytoplasm with included organelles (e.g., ribosomes, mitochondria, plastids), an enclosing membrane, and an exterior cellulosic wall. |
|
dens pl. dentes |
= tooth |
STRUCTURE |
|
One of a series of regularly spaced, angular, marginal convexities oriented more or less perpendicular to the generalized perimeter of a laminar structure. See also crena (scallop), crenule (scalloplet), sawtooth, sawtoothlet, toothlet. |
|
endocarp |
|
STRUCTURE |
|
The innermost tissue layer of a pericarp. |
|
sapwood |
|
STRUCTURE |
|
That portion of the wood (xylem) of a stem or root whose cells are still living and functional; concentric about the heartwood once the latter has begun to form. |
|
stigma pl. stigmata, stigmas |
|
STRUCTURE |
|
An exposed, localized portion of a pistil that retains deposited pollen and stimulates its germination, the pollen tubes then growing through or along it toward the ovule(s). |
|
hypogynium pl. hypogynia |
= gynophore; < stalk, stipe (broad sense, not recommended) |
STRUCTURE |
|
The basal portion of an ovary when constricted and stalk-like above the level of perianth insertion, bearing the main body of the pistil at its summit; in Cyperaceae. |
|
turion |
< sucker |
STRUCTURE |
|
A scaly sucker. |
|
rostrum 1 pl. rostra |
= beak |
STRUCTURE |
|
A relatively long, tapering, more or less rigid and pointed enation or termination. |
|
knee root |
|
STRUCTURE |
|
A specialized secondary root of a wetland tree, a portion of which projects above mean water level and appears to bend as a leg does at the knee, its distalmost portion being anchored in the substrate beneath the water. The knee of the root is commonly regarded as a conduit for gas exchange between root interior and atmosphere, a function whose need is posited on the basis of the highly anaerobic and saturated conditions prevailing in wetland substrates. |
|
mentum pl. menta |
= column foot |
STRUCTURE |
|
A lateral, often nectariferous protrusion from the proximal portion of a column, opposite the labellum, projecting in front of the rest of the flower; in Orchidaceae. |
|
cross-vein |
|
STRUCTURE |
|
A relatively short, secondary or higher-order vein that runs directly between two veins of the next lower order, intersecting them more or less perpendicularly. |
