1. Abutilon theophrasti Medik. (velvet-leaf, butter-print)

Pl. 450 g–i; Map 2042

Plants annual, densely pubescent throughout with stellate hairs. Stems 20–200 cm long, ascending to erect, branched or unbranched. Leaves long-petiolate, the blades 2.5–20.0 cm long, heart-shaped, unlobed, the base strongly cordate, abruptly long-tapered at the tip, the margins entire or shallowly toothed. Stipules shed before leaf maturity, 3–8 mm long, linear. Flowers solitary in the leaf axils or in loose terminal and axillary clusters, the bractlets subtending the calyx absent. Calyces 5–12 mm long, cup-shaped or becoming reflexed at fruiting, the sepals free nearly to the base, the lobes ovate. Petals 6–15 mm long, the tips truncate or more commonly shallowly notched, the margin otherwise entire or somewhat irregular, yellow to orangish yellow. Stamens numerous, the staminal column circular in cross-section, without a low crown of teeth at the tip, the anthers yellow. Pistils with 9–15 locules, the carpels arranged in a loose apically flattened ring. Styles fused most of their length, each branch with a globose terminal stigma. Fruits schizocarps breaking into 9–15 mericarps. Mericarps 10–18 mm long, wedge-shaped, becoming blackened at maturity, with a prominent horizontally spreading beak toward the tip, the dorsal surface lacking a longitudinal groove, oblong to kidney-shaped in profile, the lateral walls thin, smooth to slightly roughened, dehiscing apically from the center to the beak at maturity (the fruit also eventually breaking apart into individual mericarps), 3–9-seeded. Seeds 3–4 mm long, kidney-shaped to nearly triangular, the surfaces minutely stellate-hairy (appearing granular under lower magnification), black. 2n=42. June–October.

Introduced, scattered to common nearly throughout Missouri (native of Asia, widely introduced in the U.S.). Crop fields, roadsides, railroads, and open disturbed areas; rarely margins of lakes and banks of streams.

Velvetleaf originally was introduced into the United States early in the nineteenth century as a fiber plant for the production of twine, thread, and other cordage, but was soon abandoned as cheaper sources of fiber for this purpose became available. Presently, it is one of the most important broadleaf weeds of crop fields in the United States, particularly in corn and soybean fields. It is resistant to some herbicides and the seeds may persist in the soil for up to 50 years.