What is "snail flower"

Snail \Snail\ (sn[=a]l), n. [OE. snaile, AS. sn[ae]gel, snegel, sn[ae]gl; akin to G. schnecke, OHG. snecko, Dan. snegl, Icel. snigill.]

1. (Zo["o]l.)

   1. Any one of numerous species of terrestrial air-breathing gastropods belonging to the genus Helix and many allied genera of the family Helicid[ae]. They are abundant in nearly all parts of the world except the arctic regions, and feed almost entirely on vegetation; a land snail.

   2. Any gastropod having a general resemblance to the true snails, including fresh-water and marine species. See Pond snail, under Pond, and Sea snail.

2. Hence, a drone; a slow-moving person or thing.

3. (Mech.) A spiral cam, or a flat piece of metal of spirally curved outline, used for giving motion to, or changing the position of, another part, as the hammer tail of a striking clock.

4. A tortoise; in ancient warfare, a movable roof or shed to protect besiegers; a testudo. [Obs.]

   They had also all manner of gynes [engines] . . . that needful is [in] taking or sieging of castle or of city, as snails, that was naught else but hollow pavises and targets, under the which men, when they fought, were heled [protected], . . . as the snail is in his house; therefore they cleped them snails.
   --Vegetius (Trans.).

5. (Bot.) The pod of the sanil clover.

   Ear snail, Edible snail, Pond snail, etc. See under Ear, Edible, etc.

   Snail borer (Zo["o]l.), a boring univalve mollusk; a drill.

   Snail clover (Bot.), a cloverlike plant ( Medicago scuttellata, also, M. Helix); -- so named from its pods, which resemble the shells of snails; -- called also snail trefoil, snail medic, and beehive.

   Snail flower (Bot.), a leguminous plant ( Phaseolus Caracalla) having the keel of the carolla spirally coiled like a snail shell.

   Snail shell (Zo["o]l.), the shell of snail.

   Snail trefoil. (Bot.) See Snail clover, above.

n. perennial tropical American vine cultivated for its racemes of showy yellow and purple flowers having the corolla keel coiled like a snail shell; sometimes placed in genus Phaseolus [syn: snailflower, snail-flower, snail bean, corkscrew flower, Vigna caracalla, Phaseolus caracalla]