Guaiacum coulteri var. palmeri (Vall) I. M. Johnst.

Guaiacum palmeri Vail, sp. nov
A shrub or small tree (?) with corky bark, and numerous short modified branchlets ; leaves fascicled at the ends of the branchlets, 15-20 mm. long ; leaflets 4-6, mostly 6, linear-oblong, 4-10 mm. long, 2-3 cm. wide, obtuse, apiculate, coriaceous, reticulate, glabrate above, obscurely pubescent beneath ; petioles and rachis densely pubescent ; stipules subulate, minute, pubescent ; flowers 1-3, borne on peduncles 1 cm. long, produced mostly in the axils of the leaves at the ends of the branchlets ; sepals 5, oblong or obovate, about 6 mm. long, minutely pubescent, on the inner surface ; petals 5, blue, broadly orbicular-obovate, about 1 cm. long, thick, very slender at the unguiculate base ; ovary broadly obovate, stipitate, 5-angled, tomentose, abruptly contracted into the short tomentose style ; filaments filiform from a broader flat base ; anthers oblong, 2 mm. long ; fruit broadly obovoid, 10-15 mm. long, 10-15 mm. broad or more, stipitate, yellowish-green, coriaceous, minutely pubescent, 5-valved and angled, carinate on the angles ; seeds 2-3, 7-8 mm. long, elliptic, covered with a dark-red (?) fleshy aril ; endosperm bony, not very thick ; cotyledons 3-4 mm. long, oblong, 2 mm. broad, dark-green.
Type collected at Guaymas, Sonora, 1887, E. Palmer 113 (herb. Columbia Univ.). Distribution : Known only from the type locality and vicinity.