torus 2 pl. tori |
= receptacle |
STRUCTURE |
|
The short, expanded, compound axial structure surmounting a peduncle and basal to two or more flowers, or to the florets of a capitulum (head) in Asteraceae (Compositae), where it may bear paleae (receptacular bracts), scales, bristles, trichomes, or subulate enations, and may be smooth or variously pitted (alveolate, foveolate). |
embryo sac |
< megagametophyte |
STRUCTURE |
|
The multinucleate generative cell of an ovule, within which fertilization and zygote formation occur; resulting from meiotic division of a megaspore mother cell within the nucellus, and thus genetically haploid; its contents generally considered to represent an evolutionarily reduced gametophyte. |
coma pl. comae, comas |
< tuft |
STRUCTURE |
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A prominent single tuft of relatively long and slender, flexible, capillate trichomes; esp. from a seed, as in Asclepias (Asclepiadaceae). |
neck (floral tube) |
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STRUCTURE |
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The solid, usually constricted portion of a floral tube sometimes present between casing and collar when those are both present. |
thallus 2 pl. thalli |
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STRUCTURE |
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The main body of a gametophyte, bearing rhizoids, gametangia (antheridia and/or archegonia), and/or gemmae cups; usually thin and more or less planate, inconspicuous, and growing appressed to or beneath the substrate surface; in Psilotophyta, Lycopodiophyta, Equisetophyta, Polypodiophyta. See also prothallus. |
squamule 1 |
= squamella; < scale |
STRUCTURE |
|
A diminutive squama (lepis). |
primary axis |
> ray |
STRUCTURE |
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A main or first-order axis within any specified, uniformly delimited structural context. |
seta 2 pl. setae |
= bristle; > glochid, glochidium |
STRUCTURE |
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A trichome that is elongate, slender, more or less straight, terete, fine-pointed, and stiff. |
limb 1 |
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STRUCTURE |
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A relatively broad portion of a syntepalous (gamotepalous) perianth, synsepalous (gamosepalous) calyx, or sympetalous (gamopetalous) corolla distal to a narrower tube, spreading outward or ascending from the tube, comprising the distinct or connate distal portions of the tepals, sepals, or petals; except in bisexual or staminate disc florets of Asteraceae (Compositae). |
connective |
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STRUCTURE |
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The tissue between and joining the laterally opposed thecae of an anther, connecting them with the distal end of the staminal filament when the latter is present. |
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. |
rib |
= costa; > midnerve (not recommended), midrib, midvein; >< lateral vein |
STRUCTURE |
|
A primary vein of a laminar structure, having a longitudinal course, either medial or lateral, often prominent. See also secondary vein, tertiary vein, veinlet. |
aril 1 (broad sense) |
> arillode, arillus |
STRUCTURE |
|
An appendicular structure that wholly or partly envelops a seed and is produced from or a modification of the funicle, raphe, outer integument, or (in some Pinophyta) a subtending involucre; usually fleshy or pulpy, sometimes spongy or tufted-capillate, often brightly colored. |
accessory cell |
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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. |
trabecula pl. trabeculae |
< septum |
STRUCTURE |
|
A transverse wall or partition that fully or partially separates two chambers within a sporangium. |
first glume |
|
STRUCTURE |
|
The lower (proximal) or sometimes solitary small bract inserted at the base of a grass (Poaceae) spikelet, the second glume, when present, inserted immediately above (distal to) it. |
embryotega pl. embryotegae, embryotegas |
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STRUCTURE |
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A small, hardened, lid-like portion of the testa (seed coat) at the micropyle of some seeds, detaching at germination. |
massula pl. massulae |
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STRUCTURE |
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A body of coherent pollen grains, dispersed as a unit; esp. in Asclepiadaceae, Orchidaceae. |
galea pl. galeae, galeas |
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STRUCTURE |
|
A galeate (galeiform, helmet-shaped) sepal or petal in a zygomorphic calyx or corolla, differing markedly in shape from and sometimes partially enclosing the other sepals or petals. |
petiolule |
< stalk |
STRUCTURE |
|
The stalk, when present, of a leaflet, analogous to the petiole of a leaf. |
theca pl. thecae |
= pollen sac |
STRUCTURE |
|
Any of the one, two or four ontogenetically distinct, pollen-producing sectors (microsporangia) of an anther. In some taxa the walls between pairs of adjacent thecae break down as an anther approaches maturity, the mature anther thus ultimately containing half as many locules as thecae. |
squamule 2 |
= squamella; < scale |
STRUCTURE |
|
A small, dry bract borne on the compound receptacle (torus) of a capitulum (head); in Asteraceae (Compositae). |
primary root |
> taproot |
STRUCTURE |
|
The one, central root directly basal to a shoot, developing directly from the embryonic radicle; the first-formed root of a plant, being the only one truly central in nature (i.e., belonging to the original central axis of the plant). All other roots of a plant develop subsequently and are lateral in nature. The primary root may be permanently dominant, developing into a taproot; otherwise it may be transitory or become functionally subordinate, with secondary and/or adventitious roots becoming dominant. |
knee 1 |
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STRUCTURE |
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An abrupt bend in an axial or other elongate structure. |
pollen |
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STRUCTURE |
|
Collectively, the spores or grains produced within the thecae of anthers, each containing a very small microgametophyte (or its evolutionary homologue); serving as disseminules from which microgametes are released after transport to a receptive micropylar pollen droplet (in Pinophyta) or stigma (in Magnoliophyta) by a variety of vectors, notably wind, water, insects, bats, and birds. |