[V. sandwicensis A. Gray; V. s. var. heterophylla Rock]
(end, E)
Slender, twining annual or perennial herbs; stems usually 1-4 dm long, sparsely to densely hirsute, the hairs somewhat retrorsely appressed. Leaflets membranous, variable in shape, from suborbicular to rhombic-ovate, linear-deltate, or linear, 1.2-8 cm long, 0.1-2.5 cm wide, sparsely to moderately appressed hirsute, apex bluntly acute and minutely mucronulate, base broadly cuneate to subtruncate, stipels ca. 1.5 mm long, stipules deltate, up to 2 mm long. Flowers 1-4 in racemes; calyx green(?), 4-8 mm long, sparsely appressed hirtellous, upper 2 lobes nearly completely connate, forming a notched upper lip ca. 2.5 mm long, lateral lobes deltate, 2-3 mm long, lowest lobe ca. 3 mm long; corolla membranous, pale yellow or greenish yellow, 20-25 mm long, standard apparently not reflexed, broadly obovate, keel distinctly beaked, the beak truncate and open at apex; style with 2 rows of hairs below the stigma on each lateral side, not along the inner edge. Pods linear, not or slightly inflated, 40-90 mm long, 4-6 mm wide, sparsely appressed hirsute, slightly or not constricted between the seeds. Seeds 7-15, gray to black, angular-ellipsoid, 3.5-6 mm long, 3-4 mm wide. [2n = 22*.] Apparently very rare, occurring primarily in dry grassland and shrubland, 10-1,370 m, on all of the main islands except Kaua‘i.—Plate 98.
The variation in leaf size and shape from rhombic-ovate and small, orbicular forms to linear-leaved forms is quite extreme, but transitional specimens are known. Different leaf forms, although not all extremes, can be found on a single plant (e.g., the type of Vigna sandwicensis var. heterophyl- la). There is, however, a geographical component to the variation with narrower- leaved plants (V. sandwicensis) occurring on the younger islands. Verdcourt (1970c) inadvertently used the younger name V sandwicensis as the accepted name, placing V. o-wahuensis in synonymy. He placed V. o-wahuensis in sect. Vigna where it is anomalous in its long, open beak on the keel. The stylar hairs are along 2 lateral sides of the upper part of the style, which appears to be a unique feature. In other species of Vigna, the style is bearded just below the stigma at the inner edge, as in V. marina. In most other characters V. o- wahuensis seems to fit better in the African sects. Liebrechtsia (De Wild.) Bakh. f. and Reticulatae Verde., but according to Verdcourt (1970c), its relationship appears to be with sect. Vigna. The unique orientation of the stylar pubescence in V. o-wahuensis makes placement in any of the existing sections problematical.