1. Acalypha deamii (Weath.) H.E. Ahles (two-seeded mercury, large-seeded mercury)

A. virginica L. var. deamii Weath.

A. rhomboidea Raf. var. deamii (Weath.) Weath.

Map 1649, Pl. 376 i, j

Stems 20–60 cm long, glabrous or moderately to densely pubescent (sometimes in vertical lines) with short, strongly curved hairs. Leaves long-petiolate, the petiole slightly shorter than to slightly longer than the blade, much longer than the inflorescence bracts. Leaf blades 1–12 cm long, ovate to broadly rhombic, mostly broadly angled at the base, tapered to a sharply pointed tip, the margins with several (mostly 10–15 on each side) relatively closely spaced, usually blunt teeth, relatively thin-textured, the surfaces sparsely to moderately pubescent with relatively straight, more or less appressed hairs. Inflorescences entirely axillary spikes, 1–3 per node, each with 1–3 basal pistillate flowers below few to several nodes of staminate flower clusters, the tip of the spike not or only slightly extending beyond the bract. Inflorescence bracts 8–25 mm long, appearing more or less folded longitudinally around the inflorescence, with (5–)7–9 linear to lanceolate lobes, the margins sparsely to moderately hairy, the outer surface glabrous or sparsely hairy, sometimes some of the hairs gland-tipped, lacking minute, sessile, reddish glands. Fruits 2.5–3.4 mm long, 2-locular, 2-seeded, the surface moderately to densely hairy, lacking tubercles or slender projections at maturity. Seeds 2.2–3.2 mm long. 2n=40. July–October.

Uncommon and sporadic (Iowa, Kansas, and Arkansas east to Pennsylvania and Tennessee). Edges and openings of bottomland forests and banks of streams and rivers.

This taxon was not treated by Steyermark (1963), who merely mentioned its existence (as A. rhomboidea var. deamii) in adjacent states. Miller (1964) mapped the species from three Missouri counties but provided no specimen citations to document her finds. Turner and Yatskievych (1992) first cited specimens from St. Louis and Pulaski Counties. The species remains relatively poorly known and may be overlooked in the field due to its vegetative similarity with A. rhomboidea (Becus, 2003). At present it appears to be rare throughout its range. Cooperrider (1984) suggested that there were problems in distinguishing A. deamii from A. virginica and treated it as a variety of that species. However, the consistently 2-seeded fruits with seeds more than 2 mm long are diagnostic for the species (Levin, 1999a). Gleason and Cronquist (1991) and some other authors have emphasized the abruptly drooping leaf blades as a unique feature of A. deamii, but this appears to be under seasonal or environmental influence (Becus, 2003). Plants observed during the present research in Pike County had spreading leaves similar to those of A. rhomboidea plants at nearby locations.