Three-Seeded Mercury (Acalypha virginica)
In the fall this unassuming little weed can take on some surprisingly beautiful and varied autumn colors in the bronze range. This little patch grew out of a crack in a concrete driveway in Beechview, where it was beginning to show off its autumn colors (and its triple seeds) in late September. It grows everywhere in the city, although normally we don’t notice it much.
Gray describes the genus and the species:
ACALYPHA L. THREE-SEEDED MERCURY. Flowers monoecious; the sterile very small, clustered in spikes; the few or solitary fertile flowers at the base of the same spikes, or sometimes in separate ones. Calyx of the sterile flowers 4-parted and valvate in bud; of the fertile, 3-5-parted. Corolla none. Stamens 8-16; filament short, monadelphous at base; anther-cells separate, long, often worm-shaped, hanging from the apex of the filament. Styles 3, the upper face or stigmas cut-fringed (usually red). Capsule separating into 3 globular 2-valved carpels, rarely of only one carpel. — Herbs (ours annuals), or in the tropics often shrubs, resembling Nettles or Amaranths; the leaves alternate, petioled, with stipules. Clusters of sterile flowers with a minute bract; the fertile surrounded by a large and leaf-like cut-lobed persistent bract. (Akalyphe, an ancient name of the Nettle.)
Fruit smooth or merely pubescent; seeds nearly smooth.
A. virginica L. Smoothish or hairy, 3-6 dm. high, often turning purple; leaves ovate or oblong-ovate, obtusely and sparsely serrate, long-petioled; sterile spike rather few-flowered, mostly shorter than the large leaf-like palmately 5-9-cleft fruiting bracts: fertile flowers 1-3 in each axil. — Fields and open places, N. S. to Ont. and Minn., s. to the Gulf. July-Sept.