|
thyrsate |
|
architecture |
inflorescence |
Comprising one or more thyrses. |
|
throat 2 |
|
STRUCTURE |
|
The fully connate portion of the limb of a disc floret, proximal to the lobes (distinct distal portions of the petals); in Asteraceae (Compositae). |
|
throat 1 |
|
STRUCTURE |
|
The far distal portion of a perianth, calyx, or corolla tube, or of a leaf sheath, surrounding the orifice of the tube or sheath, sometimes constricted relative to the diameter of the main body of the tube or sheath; except in disc florets of Asteraceae (Compositae). |
|
thrice-… |
= tri…, triple-… |
prefix |
|
Indicating presence of three hierarchical orders of the type of entity or pattern denoted by the term's stem; as in thrice-pinnate. See also three-… (tri…). |
|
three-… |
= tri… |
prefix |
|
Indicating presence of or constitution by three entities of the type denoted by the term's stem; as in three-cleft, three-flowered, three-ranked. See also thrice… (tri…, triple…). |
|
thread-like |
= filiform |
solid shape |
|
Elongate and very slender, basically round in transverse section and of more or less uniform diameter, variously curved over its length or not. See also hair-like (capillary, capillate). |
|
thorn |
= spine |
STRUCTURE |
|
Any sharp, stiff, simple or branched, woody appendage having vascular tissues confluent with those of the bearing structure. "Spine" is often preferred when the appendage is homologous with a leaf or stipule, and "thorn" when it is homologous with a branch. See also prickle. |
|
tholiform |
= dome-shaped |
solid shape |
|
Convex overall, broadest at the base, and transversely more or less circular to elliptical throughout. |
|
thermocleistogamous |
|
reproduction |
flower |
Normally chasmogamous but facultatively cleistogamous during periods of lower-than-normal temperature. |
|
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. |
|
thallus 2 pl. thalli |
|
STRUCTURE |
|
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. |
|
thallus 1 pl. thalli |
|
STRUCTURE |
|
The vegetative portion of a shoot when not differentiated into stem and leaves; esp. in Lemnaceae. |
|
texture |
|
CHARACTER |
|
Substantial properties. Overlaps conceptually with solid shape, as to thickness. |
|
tetra… |
= four-…, quadr(i)… |
prefix |
|
Indicating presence of or constitution by four entities of the type denoted by the term's stem; as in tetrandrous, tetracarpellate, tetracolporate. See also individual entries for terms with this prefix whose meanings, at least in some applications, are more specific than usually indicated by such combination. |
|
tetradynamous |
|
architecture |
flower, androecium |
Diadelphous with four stamens in one set and two in the other. See also didynamous. |
|
tetradal |
|
arrangement |
pollen |
Shed in groups of four, each an intact tetrad with original configuration unchanged; geometric arrangement of the grains may be tetrahedral, tetragonal, or linear, depending upon mode of pollen mother cell division. |
|
tetrad scar |
|
FEATURE |
|
A surficial ridge or angle resulting from coherence with other spores produced from the same mother cell. |
|
tetrad |
|
STRUCTURE |
|
A group of four pollen grains originating from a single pollen mother cell. |
|
testicular |
= testes-shaped |
solid shape |
|
Bilaterally symmetrical, each side essentially oblate and constrictedly confluent with the other; like the overall shape of a pair of mammalian testes. |
|
testes-shaped |
= testicular |
solid shape |
|
Bilaterally symmetrical, each side essentially oblate and constrictedly confluent with the other; like the overall shape of a pair of mammalian testes. |
|
testa pl. testae |
= seed coat |
STRUCTURE |
|
The outer protective layer of a seed, developed from the ovular integument(s). |
|
tessellate 2 |
= checkered |
relief |
|
Having a pattern of regularly disposed squares marked by raised or depressed vasculature. |
|
tessellate 1 |
= checkered |
coloration |
|
Having a pattern of more or less regularly disposed square zones of contrasting hues and/or intensities. |
|
tertiary vein |
|
STRUCTURE |
|
A strand belonging to the third order of vasculature in a leaf or other basically laminar structure, except when that is the ultimate order (consisting of veinlets); branching from a primary or secondary vein. See also costa, lateral vein, primary vein, rib, secondary vein, veinlet. |
|
terrestrial |
|
habit |
plant |
Growing upon the ground, usually rooted in it. |
