Acalypha rhomboidea is an annual herb, to 60 cm tall, from a taproot, stems erect, simple or branched, smooth or finely hairy; bright green to reddish, often appearing translucent or succulent, sap watery; senescent plants often turning reddish.
Leaves alternate, stalks 1-8 cm long, blades 3-9 cm long, 2-5 cm wide, only slightly longer than stalks, narrowly egg-shaped to rhombic, tip blunt, base tapered to rounded, surface finely hairy, major veins 3, palmate at base, margin bluntly toothed (crenate), new leaves often reddish.
Flowers greenish, to yellow-green; monoecious, in axillary spikes
above (subtended by) bracts to 1.3 cm long, 1.5 cm wide, glandular-hairy (stipitate glandular), margins 5-9-lobed, lobes (teeth) 0.5 cm long, tips pointed; male flowers in a head-like cluster at tip of spike, stamens numerous; female flowers 1-5, at base of floral spike, no petals, sepals minute, styles 3, ragged (laciniate), ovary 3-lobed; wind pollinated (Cid-Benevento 1987); blooms and fruits July-Oct.
Fruit dry, a 3-parted capsule about 0.2 cm wide (Radford et al. 1968;Yatskievych 2006); seeds 3, with fleshy attachment (aril), usually an indication of ant dispersed (Handel 1978; Handel et al. 1981).
Wetland status: FACU-.
Frequency in NYC: Occasional.
Habitat: Disturbed forest understories, edges, shady lawns, gardens, roadsides (appears similar to Pilea pumila, which has opposite leaves).