Ulmus glabra ‘cornuta’ is a tree to 40 m tall; bark often smooth in young trees, new growth hairy, becoming red-brown on older twigs.
Leaves alternate, stalk to 0.3-0.6 cm long, blade 8-16 cm long, inversely egg-shaped, of two types, both unlobed and 3-lobed (rarely 5-lobed) at broad apex, tips pointed, base unequal, upper surface rough, lower surface finely hairy, margin doubly toothed.
Flowers pale green, stigmas red, in dense clusters on short stalks.
Fruit dry, flat, 1.5-2.5 cm wide, broadly winged, nearly heart-shaped, tip notched, narrowed to base, surface smooth, seed in center.
Wetland status: NL.
Frequency in NYC: Very infrequent.
Origin: Europe and Asia.
Habitat: Observed to escape and sucker rather aggressively at least locally in North Woods of Central Park (Gargiullo personal observation).
Notes: Much like U. laciniata which has smooth new growth becoming yellowish or grayish brown (not red-brown) on older twigs (Rehder 1986).