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squamule 3 |
= lodicule, squamella |
STRUCTURE |
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One of two or three small, scale-like structures inserted at the base of the androecium, distal to the palea, in most grass (Poaceae) flowers; often regarded as a vestigial branch or perianth member. |
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primary axis |
> ray |
STRUCTURE |
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A main or first-order axis within any specified, uniformly delimited structural context. |
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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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taproot |
< primary root |
STRUCTURE |
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A primary root that remains dominant through the life of the plant as the main axis of a vertically oriented system that penetrates the substrate to a considerable depth. |
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frond |
< leaf, macrophyll (not recommended), megaphyll |
STRUCTURE |
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A leaf in Polypodiophyta or Palmae (Arecaceae), usually relatively large and often highly dissected. Use of this term in preference to "leaf" in descriptions of ferns and palms is a matter of tradition only, not of morphological or evolutionary distinction. |
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calyculus 1 pl. calyculi |
= epicalyx |
STRUCTURE |
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A whorl of bracts immediately subtending (beneath or outside) a calyx; literally, a little calyx. |
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wall (fruit, ovary, pollen, spore) |
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STRUCTURE |
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The exterior layer of tissue(s) enclosing anatomically distinct interior tissues and sometimes fluid and/or one or more cavities. |
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leaf 2 pl. leaves |
= microphyll |
STRUCTURE |
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A small, lateral, leaf-like enation that, evolutionarily, is not a true leaf, i.e., whose vasculature, if any, consists of only a single median strand not ontogenetically integral with the vasculature of the bearing stem and not associated with leaf gaps in the stele of the stem; in Psilotophyta, Lycopodiophyta, Equisetophyta. |
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trabecula pl. trabeculae |
< septum |
STRUCTURE |
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A transverse wall or partition that fully or partially separates two chambers within a sporangium. |
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sucker |
> turion |
STRUCTURE |
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A shoot arising adventitiously from a root or stem below or at ground level. |
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raphides sing. raphis |
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STRUCTURE |
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Needle-like crystals of calcium oxalate contained within the cells of some plants; esp. in Araceae. |
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articulation |
= joint |
STRUCTURE |
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A distinct, relatively narrow zone of demarcation between adjacent main portions of an elongate structure, often thicker than the rest of the structure and sometimes a site of eventual abscission. |
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corolla tube 1 |
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STRUCTURE |
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A relatively narrow, fully connate portion of a sympetalous (gamopetalous) corolla proximal to a broader portion (limb) that comprises the distinct or connate distal portions of the petals; except in bisexual or staminate disc florets of Asteraceae (Compositae). |
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sheath (leaf) |
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STRUCTURE |
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The lower (basal or proximal), fundamentally laminar but strongly involute portion of one of the non-petiolate leaves characteristic of most monocotyledons (Liliidae); distinct from the leaf blade, which, when present, is borne distally upon it; analogous, though not necessarily homologous, with a petiole; usually more or less completely enclosing a portion of the stem above the node from which the leaf is borne. |
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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. |
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claw |
= unguis |
STRUCTURE |
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The abruptly much narrower proximal portion, when present, of a laminar structure, esp. a petal; of variable shape itself, but usually attenuate toward the base. |
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sepal |
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STRUCTURE |
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One of the one or more constituent members of a calyx; usually green and leaf-like, but sometimes with color and/or texture otherwise, sometimes petaloid; may be distinct or else connate with one or more others and/or may be free or else adnate to one or more other floral structures. |
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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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segment |
? division, lobe |
STRUCTURE |
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Any generally convex, major peripheral protrusion or component sector that is delimited by concavities in the surface or margin and that is not proximally distinct from the remainder of the whole. |
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fruit |
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STRUCTURE |
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Any unitary seed-bearing structure of a flowering plant, consisting of the matured or ripened pistil(s) of one or more flowers along with any other floral or vegetative tissue(s) persisting adnate to them; characteristic of and unique to Magnoliophyta (Angiospermae). |
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ovule |
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STRUCTURE |
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A complex reproductive structure borne by a seed-plant sporophyte, consisting of outer, sporophytic tissues that enclose a haploid, gametogenic tissue usually regarded as a highly reduced megagametophyte. Following fertilization, the entire structure matures to become a seed that contains an embryo, the first stage of the next sporophytic generation. Ovules (and seeds) are borne naked on megasporophylls (in Pinophyta) or within an ovary (in Magnoliophyta). |
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calyculus 2 pl. calyculi |
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STRUCTURE |
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Collectively the bractlets (bracteoles) sometimes subtending (beneath or outside) the involucre in a capitulum (head); in Asteraceae (Compositae). |
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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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flower |
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STRUCTURE |
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A functionally integrated, complex structure comprising sets of sporophytic and/or associated sterile structures disposed in standard sequence along a common axis; consisting of one or more constituent members each of, in ascending (proximal to distal) order of insertion, perianth (tepals, or else sepals and/or petals), androecium (stamens, staminodes and/or other associated structures), and/or gynoecium (pistils and/or other associated structures), the foregoing all borne laterally from the distal portion (receptacle) of the axis; depending upon the combination of structures present, may be bisexual, staminate only, pistillate only, or sterile; characteristic of and unique to the Magnoliophyta (Angiospermae). When a fertile androecium and gynoecium are both present a flower is termed perfect. When perfect and also with calyx and corolla both present, a flower is termed complete. Both terms are somewhat archaic and of limited descriptive value. |
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microphyll |
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STRUCTURE |
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A small, lateral, leaf-like enation that, evolutionarily, is not a true leaf, i.e., whose vasculature, if any, consists of only a single median strand not ontogenetically integral with the vasculature of the bearing stem and not associated with leaf gaps in the stele of the stem; in Bryophyta, Psilotophyta, Lycopodiophyta, Equisetophyta. |
