Lamina of larger leaves 16-26 cm long, 11-16 cm wide, broadly elliptical, broadly cuneate at base, rounded and apiculate or shallowly retuse at apex, adaxially glabrate at maturity except persistently loosely sericeous on midrib, abaxially densely and persistently appressed-tomentose with the hairs sessile or short-stalked and the crosspiece ca.
9-3 cm wide, elliptical or narrowly ovate, cuneate to rounded and sometimes short-decurrent at base, flat or slightly revolute at margin, abruptly short-acuminate or obtuse and apiculate at apex, glabrous or bearing a few short appressed hairs abaxially near base, bearing 2 large raised glands on abaxial surface at base and occasionally 1 or 2 additional glands on abaxial surface above base, the glands rarely on decurrent laminar tissue and appearing to be on apex of petiole, the principal lateral veins 4-6 on each side of midrib; petiole of larger leaves 7-14 mm long, very sparsely sericeous to soon glabrate, eglandular except for glands on decurrent lamina (see above); stipules 0.
3 cm in diameter; lateral wing membranous, continuous at base and apex, not cleft at apex but broadly and shallowly emarginate, nearly glabrate at maturity; dorsal winglet 8-10 mm wide, prolonged upward toward apex of samara and confluent with lateral wing; ventral crest 1-1.
Epicarp smooth (rarely with indument, scale-like spines or glabrate when fruit unripe); pistillate flowers 2-5 per rachilla--6
Caespitose palms; calyx of the pistillate flower glabrate (some bristles are always present), usually longer than 15 mm; fruit with 5-6 mm long bristles or armed with spines--Astrocaryum urostachys