distichous


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distichous

[′dis·tə·kəs]
(biology)
Occurring in two vertical rows.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Morphologic characters used in the past to circumscribe Cypereae members, such as presence of spikelets with distichous glumes, and reduced perianthless flowers, are not useful to characterize the modern Cypereae tribe (Larridon et al., 2013).
Inflorescence terminal, erect, simple, peduncle terete, 45-50 cm long, 5-7 mm in diameter, totally covered by the bract sheaths; basal peduncle bracts green to reddish, imbricate, vaginiform, only the basal ones foliaceous; sheaths 3.5-4.5 cm long, blades 1-30 cm long; spike compressed, oblong to lanceolate, 17-30 cm long, 6-7 cm wide; floral bracts dark green, glaucous, widely elliptic, 3.2-4 cm long, 2-2.4 cm wide, imbricate but the rachis visible after anthesis, smooth to nervate, ecarinate, glabrous outside, sparsely brown punctulate-lepidote inside, apex rounded; flowers distichous, ascendent, 13-22 per spike, actinomorphic, corolla helicoiform, subsessile; sepals free, green, oblanceolate, 3-3.4 cm long, ca.
Inflorescence 13-30 cm long, 5-6 cm wide, once branched or rarely two times branched in the lower part, lax, bearing 6 to 11 spikes 2-2.5 cm apart, yellow-green, complanate, lepidote, slightly curved, distichous, spikes slightly nodding; peduncle 15-20 cm long, ca.
In species of Scleria with the latter type of spikelet--considering each axis separately (the main axis and the branched paracladia)--, the phyllotaxy pattern changes first from spiral (in the vegetative part) to distichous and then again from distichous to spiral.
Leaves up to 3, basal, deciduous, erect, distichous, membranous (slender and translucent when dry), linear-lanceolate, acuminate, minutely dentate along the margins, carinate on the external surface, 6-10 cm x 1-2 mm.
1987 Werner Rauh introduced us to a startling distichous leaved Dyckia but in the same year he gave a more reasoned account regarding its origins in German in Trop.
A remarkable maize mutant, aberrant phyllotaxy1 (abph1) displays a decussate phyllotactic pattern (leaves are paired at 180[degrees] and the following leaf pair develops at a 90[degrees] angle) while wild type maize develops as distichous (alternating leaf initiation) plants.