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pseudostem |
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STRUCTURE |
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A structure that resembles a stem but is not part of the axial system of a shoot, lacking anatomical differentiation into nodes and internodes. |
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squamella 1 pl. squamellae |
= squamule; < scale, trichome |
STRUCTURE |
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A diminutive squama (lepis). |
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vesicle |
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STRUCTURE |
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A small bladder-like part consisting of an enclosing wall or covering and an empty or fluid-filled interior, sometimes turgid; esp. in citrus fruits (hesperidia). |
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primary root |
> taproot |
STRUCTURE |
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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. |
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seed |
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STRUCTURE |
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A mature or ripened ovule containing an embryonic sporophyte and a nutritive tissue (endosperm or perisperm) with stored food that sustains the initial growth of the embryo upon germination, except when such food reserve is stored instead in the cotyledon(s) of the embryo itself, these enclosed by one or two integuments (the testa), the whole serving as a propagule. A fertile seed (one containing a viable embryo) normally results from sexual fertilization of an egg by a sperm; however, fertile seeds are sometimes produced asexually by apomictic processes (e.g., parthenogenesis). |
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integument |
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STRUCTURE |
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A distinct layer of tissue that encloses and serves to protect the other tissues of an organ, especially a seed. |
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throat 2 |
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STRUCTURE |
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The fully connate portion of the limb of a disc floret, proximal to the lobes (distinct distal portions of the petals); in Asteraceae (Compositae). |
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ligule 3 |
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STRUCTURE |
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A relatively small, attenuate, membranous, laminar enation from the adaxial surface of a leaf near its base; in Selaginella, Isoetes. |
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areole 1 |
= areola |
STRUCTURE |
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Any distinctive surficial discontinuity of generally circular outline, whether concave, flush, or convex; when protuberant, sometimes bearing trichomes or spines, as in some Cactaceae. This term is used only when such entities are deemed structurally distinctive enough to merit description in their own rights, rather than as aspects of the surface. |
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bracteole 1 |
= bractlet; < bract |
STRUCTURE |
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A diminutive bract, or a bract that is smaller than others present. |
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node |
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STRUCTURE |
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One of the evident sectors of a stem that occur sequentially along its length and from which leaves (megaphylls) and lateral branches arise exogenously. The anatomy of nodes differs from, but is not abruptly distinct longitudinally from, that of the intervening sectors (internodes), with which it is smoothly confluent and from which is distinguished by the lateral transit and egress of vascular traces interconnecting the stem and the leaves and branches that it bears. |
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corniculum pl. cornicula |
= horn |
STRUCTURE |
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A straight or curved, slenderly conic or conoidal protrusion or terminal portion that resembles an animal horn. |
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pollen |
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STRUCTURE |
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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. |
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epidermis pl. epidermides, epidermises |
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STRUCTURE |
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The anatomically distinct, outermost, living tissue that encloses and protects the other tissues of a plant organ or part, usually overlaid by an exuded waxy cuticle; resulting from primary growth, disrupted and shed as a consequence of secondary growth if that occurs; consisting mainly of cells not further specialized, otherwise including various types of more specialized cells associated with trichomes and stomates. |
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tepal |
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STRUCTURE |
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Any member of an undifferentiated perianth; may be green and foliaceous or colored and petaloid, distinct or else connate with one or more others, and/or free or else adnate with one or more other floral structures. |
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pale 2 |
= palea, palet |
STRUCTURE |
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The upper or distal of the (usually) two distinctive bracts immediately subtending the flower in a grass (Poaceae) spikelet. |
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palea 1 pl. paleae, paleas |
= pale, palet, receptacular bract |
STRUCTURE |
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A small papery (chartaceous) to membranous bract borne on the compound receptacle (torus) of a capitulum (head) in Asteraceae (Compositae). |
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glochidium pl. glochidia |
= glochid; < bristle, capillus, hair, seta, trichome |
STRUCTURE |
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A capillus (hair) or bristle (seta) that bears one or more barbs; esp. in Cactaceae. |
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barbellula pl. barbellulae |
= barbellule |
STRUCTURE |
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A small barbel (barbella); a very diminutive barb. |
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cane |
< culm, stem |
STRUCTURE |
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A woody, aboveground culm. Use of this term or culm instead of stem is a matter of tradition and preference, not of descriptive precision or necessity. |
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root 1 |
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STRUCTURE |
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Collectively, all those portions of a plant body that are anatomically distinct from the shoot, the component axes not differentiated into nodes and internodes, and branching endogenously. |
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squamella 2 pl. squamellae |
= squamule; < scale |
STRUCTURE |
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A small, dry bract borne on the compound receptacle (torus) of a capitulum (head); in Asteraceae (Compositae). |
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isthmus |
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STRUCTURE |
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A narrower portion connecting two wider or broader portions of an inclusive structure. |
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primary stem |
= main stem; > bole, trunk |
STRUCTURE |
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The one, or any of the more than one, first-order stem(s), or first-order portion(s) of the collective stem, of a shoot. |
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seed coat |
= testa |
STRUCTURE |
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The outer protective layer of a seed, developed from the ovular integument(s). |
