Plant: tree; to 10 m high, essentially glabrous except for tomentose inner surface of bud scales; young twigs dark purplish-red to reddish-brown, the epidermis of older twigs flaking off in thin whitish sheets; buds covered with two valvate pink to red scales Leaves: deciduous, suborbicular in outline, 3-7 cm long, 3.5-9 cm wide, palmately 3-lobed (2 additional basal lobes sometimes present) or 3-foliolate, often a mixture of both types present, discolorous, the leaflets, when present, elliptic to subrhombic; apex of leaf and principal lobes or leaflets acute or obtuse; base cordate to obtusely cuneate, the base of leaflets cuneate to acuminate; petiole 1.5-9 cm long; margin coarsely serrate, the several teeth acute to acuminate Inflorescence: corymbose Flowers: ca. 5 mm long, ca. 1.5 mm wide at base of perianth, the perianth greenish-yellow, with 10 sublinear segments ca. 4 mm long, the receptacle obconic; inflorescence corymbose, ca. 1.5 cm long, the pedicels 0.2-0.5 cm long Fruit: samaras 2-2.3 cm long, the wing ca. 1 cm wide Misc: In conifer forests, especially along streams; 2100-2900 m (7000-9500 ft);; May (retaining fruits until Aug and Sep) REFERENCES: Landrum, Leslie R. 1995. Aceraceae. J. Ariz. – Nev. Acad. Sci. 29(1): 2, 2-3.