Cochlianthus

Taxonomy

Cochlianthus G. Bentham In Miquel, Pl. Jungh. 234. Aug 1852.

Subfamily: Faboideae.
Phylogenetic Number: 3.10.08.
Tribe: Phaseoleae.
Subtribe: Erythrininae.
Species Studied - Species in Genus: 2 studied; 2 in genus.

Description

Fruit: A legume; unilocular; 8.1 cm long; 1 cm wide; 0.3 cm thick; 2–9 times longer than wide; with deciduous androecial sheath; with persistent corolla; with various petals; with persistent calyx; with calyx shorter than fruit; without orifice formed by curving of fruit or fruit segments; straight; not plicate; not twisted; symmetrical; slightly moniliform, or oblong; not inflated; compressed; with beak; straight; with solid beak the same color and texture as fruit; short tapered at apex; oblique with longitudinal axis of fruit; tapered at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous; seed chambers externally visible; seed chambers with the raised seed chambers not torulose; margin constricted; margin slightly constricted along both margins; margin without sulcus; margin plain; wing(s) absent; nonstipitate; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; apical and down; active; with valves twisting. Replum invisible. Epicarp dull; monochrome; black to brown; with surface texture uniform; pubescent and indurate; with hairs erect; with 1 type of pubescence; very dense tomentose; with pubescence gray-brown, or brown (dark); with pubescence uniformly distributed; with simple hairs; pliable; with hair bases plain; eglandular; without spines; not smooth; with elevated features; not veined; not tuberculate; obliquely striate; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thin to trace; surface not veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid; chartaceous. Endocarp present; visible; dull; opaque; mottled; brown; with mottling more or less uniform (dark); with black overlay; fibrous; without adhering pieces of testa; septate; with septa thicker than paper, firm; with septa eglandular; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 6; length oblique to fruit length; neither overlapping nor touching; in 1 series. Funiculus 1.5 mm long; of 1 length only; flattened; triangular. Aril present; dry; when dry 2-lipped rim-aril; entire; covering less than 1/2 of seed; with tongues (or flap) on lips of 2-lipped rim-aril; with 2 tongues or flaps, 1 on each lip of 2-lipped rim-aril; ivory.

Seed: 8.8 mm long; 7.6 mm wide; 3.5 mm thick; not overgrown; angular; asymmetrical; irregular; compressed; with surface smooth; without visible radicle and cotyledon lobes; with shallow hilar sinus; without umbo on seed faces; without medial ridge on each face. Cuticle not exfoliating; not inflated; not wrinkled. Testa present; without pieces of adhering epicarp; not adhering to endocarp; free from endocarp; dull; not modified by a bloom; colored; monochrome; black; glabrous; smooth; chartaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; partially concealed; concealed by aril; with faboid split; with the lips of the faboid split the same color as the rest of the hilum; larger than punctiform; 2 mm long; with curved outline; elliptic; apical according to radicle tip but marginal according to seed length; recessed; within halo; halo lighter than testa. Lens discernible; 1.5 mm long; with margins straight; linear; not in groove of raphe; confluent with hilum; flush; similar color as testa; lighter than testa; brown; not within corona, halo, or rim. Endosperm present; thin; not pluglike and not resembling tip of radicle; covering entire embryo; adnate to testa. Cotyledons smooth; both outer faces convex; both the same thickness; both more or less of equal length; not folded; margin entire 180 degrees from base of radicle; similar at apex; partially concealing radicle; notched at radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed; white; inner face flat; glabrous on inner face. Embryonic axis right angled; perpendicular to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; linear; lobe tip straight; with 90 degree turn; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary; glabrous.

Distribution

Himalayas and southwestern China (Yunnan province).

Old World; India and China (Nepal and Yunnan province).

Generic Notes

Lackey (1981) noted that Cochlianthus is "a very close relative of Apios (10.07), possibly congeneric." Our fruit and seed data do not support Lackey's conclusions. Woods (1988) revised both Cochianthus and Apios, and his distributions and species counts were used. He concluded that the two genera are separate, but closely related. One fruit and seed were studied, and the seed was immature without a developed embryo or cotyledons.

Tribal Notes

Tribe Phaseoleae

Bruneau et al. (1995) carried out cladistic analyses of tribe Phaseoleae using chloroplast DNA restriction site data. Their results indicated that the tribe is not monophyletic and that the tribal delimitations between Phaseoleae and Desmodieae (11) and between Phaseoleae and Millettieae (7) are problematic.