retrorse


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retrorse

[ri′trȯrs]
(biology)
Bent downward or backward.
References in periodicals archive ?
Aedeagus as in generic description, with shaft curved ventrad furnished with retrorse small spines, periandrum obtusely bent caudally at apical third; a small slightly sclerotized plate contacts the periandrum with the ventral margin of the anal segment; connective stout, long, length/wide 10:1 (Fig.
24) with 23-26 ([male] [female]) strongly retrorse teeth, most with arcuate margins; movable finger (Fig.
5 dm, erect, usually divaricately branched above, strigillose with retrorse or rarely spreading trichomes.
Head narrow; perifacial rim narrow and terminating in a retrorse spine; rostral and nasal spines absent (Fig.
5-5 cm in diameter (including floral bracts), floral bracts narrowly ovate, apex acuminate, distinctly canaliculate, navicular, ecarinate, strongly recurved, exceeding the sepals, yellowish-green to orange (when fully exposed), thin in texture, inconspicuously and sparsely white-lepidote near the base to glabrous, glabrous toward the apex, nerved abaxially, 25-35 x 11-15 mm, densely spinose, spines narrowly triangular, the basal ones retrorse the median to apical ones antrorse, uncinate, greenish except for the pale castaneous apex, 0.
Perigynia with a conspicuous exserted rachilla tipped by a retrorse, inrolled scale (i.
5 cm long, abaxially completely covered by a coarse layer of white trichomes, adaxially sparsely and inconspicuously white lepidote except for the densely white lepidote apex, coarsely spinulose, spines sub-triangular, uncinate, blackish, 3-5 mm long, 8-20 mm apart, the basal ones prevailing antrorse, the upper ones prevailing retrorse.
5 mm wide at base, 2-3 mm apart from each other, acicular, spreading to slightly retrorse, reddish-castaneous, glabrous.
5 mm long, 3-8 mm apart, the basal ones subspreading to slightly retrorse, the upper ones slightly antrorse-uncinate.
5-4 cm in diameter; floral bracts narrowly ovate, apex acuminate, distinctly canaliculate, navicular, ecarinate to obtusely carinate, strongly recurved, exceeding the sepals, dark red to wine colored toward the apex, thin in texture to thinly coriaceous, abaxially sparsely white-lepidote near the apex to glabrous, distinctly nerved, adaxially glabrous, 18-30 x 9-13 mm, densely spinose, spines narrowly triangular, retrorse to antrorse, straight to strongly recurved-uncinate, dark red, ca.
5 cm wide at the base, dark green to purple red, gray lepidote on both surfaces, stronger beneath; margins serrate with strong, retrorse, black, 3-7 mm long spines, covered by white scales, 6-8 mm apart.
warmingii) that has aggregated pistillate flowers in umbellas, ovoid or oblong fruits and scabrous and retrorses spines, and Section Atractocarpos (which includes S.