|
placenta pl. placentae, placentas |
|
STRUCTURE |
|
An ovule-bearing zone of the tissue surface bordering an ovary locule; of merely topographic, not histological, significance; may be a part of the ovary wall proper or an extension from it, or a part of the central axis of the ovary or an extension from it. |
|
wiry |
|
architecture |
axis |
Relatively very narrow and elongate, tough, and resiliently flexible. |
|
explosive |
|
dehiscence |
|
Opening abruptly with almost instantaneous aperture formation and release of accumulated structural tensions, the contents thus forcibly expelled. |
|
non-septate |
|
architecture |
trichome |
Lacking transverse inter- or intracellular septa or partitions. |
|
arillate |
|
architecture |
seed |
Having an aril. |
|
cuspidate |
|
apex |
|
Tapering gradually to a rigid tip composed of both vascular and laminar tissues. |
|
lenticel |
|
STRUCTURE |
|
A specialized, anatomically distinct structure within the periderm of a stem, consisting of comparatively spongy, sometimes suberized tissue distinct from others of the periderm; extending radially through the periderm and visible as a circular to elongate discontinuity in the color, texture, and/or relief of the outer surface of the stem; serving as a conduit for gas exchange between the stem interior and the atmosphere. |
|
polyadal |
|
arrangement |
pollen |
Shed in groups of more than four, each group comprising grains from two or more original tetrads, the latter intact or not. |
|
channel |
|
FEATURE |
|
A longitudinal, transversely rounded depression; esp. along the adaxial surface of a petiole or petiolule. |
|
sap |
|
SUBSTANCE |
|
Generally, the fluid content of a plant body; more precisely, the sugary fluid transported by the phloem. |
|
deliquescent 2 |
|
texture |
|
Delicately fleshy and liquifying at maturity or with pressure; e.g., petals of Tradescantia (Commelinaceae). |
|
prolate |
|
plane shape |
|
Symmetrically elongate parallel to the developmental or polar axis. |
|
fixed |
|
fixation |
|
Attached to the bearing structure in a manner allowing no significant rotation or declination in relation to it. |
|
opaque |
|
coloration |
|
Not transmitting light. |
|
scarious |
|
texture |
|
Very thin, dry, and not green. |
|
bark |
|
STRUCTURE |
|
The outermost portion of any shoot or root axis having secondary growth, consisting of all those tissues outside the vascular cambium; sometimes exhibiting zonation into inner, living bark and outer, dead bark; usually described only as to external appearance. |
|
stilt-rooted |
|
architecture |
plant |
Bearing and partly supported by stilt roots. |
|
hypogynous |
|
insertion |
perianth, calyx, corolla, androecium |
Entirely free from the gynoecium or any floral cup, arising from a level proximal or lateral to the base of the gynoecium. See also epigynous, perigynous. |
|
strobiloid |
|
architecture |
flower |
Characterized by a general lack of adnation among the different sets of basic floral structures, any significant degree of fusion limited to connation within sets, thus with ovary(ies) superior and lacking a floral tube. |
|
foliar |
|
insertion |
|
Upon or otherwise directly associated with the leaves. |
|
inflexed |
|
orientation |
|
Bent adaxially at some point along its length. |
|
branch |
|
STRUCTURE |
|
Any higher-order division of or outgrowth from an axis, vein or veinlet when such division or outgrowth is equivalent in nature to the structure of origin. |
|
full |
|
extent |
|
Reaching from the ovary wall or pericarp to the center of the ovary or fruit and from the apex to the base of its interior, thus separating adjacent locules completely. |
|
radiant 1 |
|
architecture |
capitulum (head) |
Bearing one or more peripheral series of florets that are bisexual, pistillate, or neuter and that have relatively large actinomorphic corollas, and one or more central series of usually bisexual florets that have relatively small actinomorphic corollas; in Asteraceae (Compositae). |
|
intruded |
|
placentation |
|
Upon partial septa excrescent from the wall of a compound, unilocular ovary. |
