6. Acalypha virginica L. (Virginia copperleaf)

Map 1654, Pl. 376 h

Stems 15–60 cm long, sparsely to densely pubescent (sometimes in vertical lines) with short, strongly curved hairs, usually also with sparse to dense, longer, straight hairs. Leaves relatively short-petiolate, the petiole 1/4–1/2 as long as the blade, usually longer than the inflorescence bracts. Leaf blades 1–12 cm long, lanceolate to narrowly ovate or narrowly rhombic, angled or slightly rounded at the base, angled or tapered to a sharply pointed tip, the margins with few to several (mostly 3–8 on each side) usually broadly spaced, blunt, shallow teeth, sometimes appearing shallowly scalloped or slightly undulate, relatively thin-textured, the surfaces sparsely pubescent mostly along the veins with short, straight to curved, 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 often extending somewhat beyond the bract. Inflorescence bracts 4.5–20.0 mm long, appearing more or less folded longitudinally around the inflorescence, with (9–)10–15 triangular-ovate to broadly oblong lobes, the margins sparsely to densely bristly-hairy, usually lacking gland-tipped hairs, the outer surface sparsely hairy, usually lacking gland-tipped hairs, rarely with sparse, minute, reddish, sessile glands. Fruits 1.5–2.3 mm long, 3-locular, usually 3-seeded (rarely 1 of the ovules aborting), the surface moderately hairy and sometimes also with minute, sessile glands, occasionally with a few minute, low, warty projections when young but smooth at maturity. Seeds 1.3–2.0 mm long. 2n=40. July–October.

Scattered nearly throughout the state (eastern U.S. west to South Dakota and Texas; introduced in Europe). Bottomland forests, mesic to dry upland forests, savannas, upland prairies, margins of ponds, lakes, and sinkhole ponds, and ledges and tops of bluffs; also fallow fields, old fields, pastures, cemeteries, ditches, gardens, railroads, roadsides, and open, disturbed areas.

Cooperrider (1984) pointed out problems in distinguishing A. rhomboidea, and A. virginica, treating these taxa as varieties of A. virginica. However, Levin (1999a) had no trouble in distinguishing them in his quantitative morphological studies of the group. Steyermark (1963), who suggested that A. virginica apparently was expanding its range northward during the decades of his research on the flora, also suggested occasional hybridization between A. virginica and A. gracilens. However, there has been no subsequent experimental confirmation of such hybrids. Steyermark also noted the existence of occasional specimens difficult to place in either A. rhomboidea or A. virginica. Such specimensfor example, occasional plants with exceptionally short petioleswill continue to vex Missouri botanists but fortunately are relatively rarely encountered. Although a great deal has been written about the morphology of the complex, it would benefit from additional biosystematic and population-genetic investigations. Even the chromosome numbers in the complex are not known with certainty, as Millers (1964) counts based on contradict earlier reports based on (Webster, 1967).