Liana; branches with coarse, short, spinescent stipules; branchlets +/- glabrous, bearing thick, spinescent stipules 5-10 mm long; outer bark smooth and flaking. Leaves compound; petiole and rachis usually inconspicuously pubescent; petiolules wrinkled, 2-6 mm long; leaflets 9-11, alternate or opposite on rachis, ovate, oblong, or obovate, obtuse to abruptly acuminate, obtuse to rounded at base, 3-10 cm long, 1.5-4.5 cm wide (juveniles to 19 cm long and 8.5 cm wide), glabrous on upper surface, minutely appressed-pubescent on lower surface, the major lateral veins 10-14, much more conspicuous than secondary veins and merging imperceptibly with the enlarged, discolored leaflet margin. Panicles axillary, 4-7 cm long, the branches densely golden-puberulent; bracteoles ca 1.3 mm long; flowers mostly sessile, white with a purple throat; calyx urceolate, 3-4 mm long, the lobes very short, obtuse; standard glabrous, ca 6.5 mm long, abruptly flexed near the middle; keel and wings to ca 5 mm long; stamens monadelphous, the filaments about half the length of the sheath; ovary pubescent, the trichomes dense, brown, appressed. Fruits unknown. Croat 10093, 17033, Woodworth & Vestal 422 (type of M. woodworthii Standl.).