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 (rĭ-trôrs′, rē′trôrs′)
Directed or turned backward or downward.

[Latin retrōrsus, from retrōversus : retrō-, retro- + versus, past participle of vertere, to turn; see wer- in Indo-European roots.]

re·trorse′ly adv.


(Botany) (esp of plant parts) pointing backwards or in a direction opposite to normal
[C19: from Latin retrōrsus, shortened form of retrōversus turned back, from retro- + vertere to turn]
reˈtrorsely adv


(ˈri trɔrs)

turned backward.
[1815–25; < Latin retrōrsus, contracted form of retrōversus bent backward]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Adj.1.retrorse - bent or curved backward or downward; "leaves with retrorse barbs"
biological science, biology - the science that studies living organisms
antrorse - bent or curved forward or upward; "a plant having antrorse hairs on the stem"
References in periodicals archive ?
5 cm long; the calyx reaches to 1 cm long, and the white, funnel-shaped corolla to 7 cm long, with a tube to 2 cm long, with retrorse fimbriae in the inner surface of the corolla, at the level of the insertion of the included stamens; the anthers reach 5 mm long, are tighly appresed to the stigma, and are villous at their apices; the fruits are straight, slender, paired follicles to 12 cm long, with narrow, plumose seeds.
7) in head length; upper jaw with 14-15 sender, slightly incurved teeth on each side, progressively larger towards front of jaw; also inner row of about 10 slender, teeth and pair of large, retrorse canines at front of upper jaw; front of lower jaw with 2-3 rows of incurved teeth nearly as large as those of upper jaw, ending in pair of large recurved, well-spaced canines about one-third back in jaw; remainder of jaw with single row of small incurved teeth; no teeth on vomer or palatines; roof of mouth with prominent papillae; edge of lips smooth; tongue tip truncate to broadly triangular; no distinct mental flap.
Aedeagus curved ventrad, bent in "C" shape, shaft slightly compressed, with small retrorse spines, abruptly narrowing at distal fourth; phallotrema subapical on dorsolateral surface; periandrum as a transverse strut obtusely bent caudally against the phallotheca, periandrum and anal segment in close contact; connective long, stout, shortly braced to the periandrum above tectiform structure.
Males with one or two small, retrorse bony hooks per segment on first to seventh or eighth segmented rays.
Lip fleshy, flat, unguiculate; the claw semi-cylindrical, with a longitudinal keel, 2-3 mm long; blade 3-lobed, ovate-sagittate, sometimes convex; lateral lobes auricled, retrorse, 1.
In many species, the perianth parts are reduced to bristles or setae with retrorse prickle hairs.
Ptilothrix is distinguished, among other emphorines, by a suite of characters that includes the lack of arolia, the elongate first flagellomere, the bowed, elevated upper margin of the clypeus coupled with a short proboscis, the reduced apical projection of the female hind basitarsus, and the type of scopal hairs on the outer surface of the hind tibia, which have the branches not retrorse, but arising at acute angles to the axes of the hairs and directed apicad.
armasi by the shape of the fixed chelal finger teeth which are long and erect in the two Cuban species, but short and retrorse in P.
The elongated tapering spine consists of a thin outer layer of enamel-like material, an inner core of vasodentine, and retrorse serrations along the lateral margins.
Mouth slightly oblique, lower jaw projecting about 1 mm in front of upper lip; maxilla reaching vertical at rear edge of orbit; lower jaw with band of minute slender teeth, band widening anteriorly, with small conical tooth projecting dorsolaterally on each side at front of lower jaw, followed by large, curved, retrorse canine posterior to the smaller conical tooth at front of jaw.
4-2 cm corolla tube Corolla lobes curved strongly retrorse Androecium exserted 1.