decurrent


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Related to decurrent: excurrent

de·cur·rent

(dē-kŭr'ĕnt),
Extending downward.
[L. de-curro, pp. -cursus, to run down]

decurrent

(of plant structures) having the base of an organ extended down its axis; for example, a decurrent leaf has the blade continued downwards as a wing along the PETIOLE.

de·cur·rent

(dē-kŭr'ĕnt)
Extending downward.
[L. de-curro, pp. -cursus, to run down]
References in periodicals archive ?
1 mm wide, spherical, shiny, yellowish to orangish clear, sessile to stalked; basal basiscopic segment of pinnules becoming decurrent and adnate to the pinna rachises, the vein supplying the segment springing from the pinna rachis instead of the costule; hydathodes present or (more rarely) absent; indusia absent or (less commonly) present, circular, brown, firm, attached at the base of a sinus, in some species minute and fugacious; spores monolete, nongreen, the perispores cristate or spiny, non-fenestrate or rarely so (2 species); x=41 (Kramer and Green 1990).
The decurrent false aster was placed on the federal list of threatened species in 1988, and is considered threatened in Illinois and Missour--the only states in which it occurs.
Leaves alternate, rarely opposite, spreading along the stem or clustered in a basal rosette, in the median part of the stem, or at the stem apex; sessile, clasping, decurrent to petiolate, occasionally with stipules; blades simple, rarely compound, entire to divided, unarmed to spiny, predominantly pinnately veined, less commonly three-veined, palmately veined, or parallel-veined, glabrous to pubescent.
Hymenium: Gills, slightly decurrent, well separated, varying from narrow to broad, white initially, becoming pinkish-brown with age.
20 mm long (with extended petals), sessile, densely arranged, odorless; sepals symmetrical or nearly so, ovate, 12-13 x 4-5 mm, free, entire, green, rigid, densely and coarsely white-floccose-lepidote except for the glabrous margins, apex acuminate-caudate, pungent, the adaxial ones carinate with keels decurrent on the ovary, the abaxial obtusely carinate; petals narrowly sublinear-spatulate, rounded and inconspicuously cucullate, ca.
Capitulescences monocephalous, heads subterminal; capitula pedunculate, homogamous, bilabiate, six- to many-flowered; receptacle epaleate; involucre multiseriate, hemispherical, phyllaries subequal, the outer phyllaries commonly decurrent onto the peduncle.
Once, clouds of a unique wildflower, the decurrent false aster (Boltonia decurrens), lined the banks of the Illinois River, but the construction of a system of locks and dams has nearly eliminated the plant's habitat.
0 cm wide, rounded (appearing reniform when conduplicate), base narrowly decurrent, adaxial surfaces covered with subulate scales similar to those of the sterile fronds; margins membranous.
5 mm, free, entire, pale green, finely nerved, thin in texture, inconspicuously white-lepidote along the central-distal portion to glabrous, the adaxial ones carinate with keels decurrent on the ovary, the abaxial one obtusely if at all carinate; petals spathulate, apex rounded and remotely apiculate, ca.
Capitulescences corymbose; capitula pedunculate, homogamous, bilabiate; receptacle epaleate; involucre multiseriate, outermost phyllaries decurrent onto the stalk.
50 cm long), and blade lanceolate with base long decurrent and acuminate apex.
5 mm, connate at base for 2-3 mm, entire, greenish, subdensely and coarsely white-lepidote, the posterior ones carinate with keel slightly decurrent on the ovary, the anterior one obtusely if at all carinate; petals broadly spatulate, 31-33 x 9 mm, connate at base for 2-4 mm in a common tube with the filaments and style, white, the free lobes broadly obovate, obtuse to slightly emarginate, suberect at anthesis, distinctly exceeding the stamens, bearing 2 longitudinal callosities ca.