1. Urtica chamaedryoides Pursh (nettle, weak nettle)

Pl. 571 i, j; Map 2674

Plants annual, with short taproots. Stems 15–80(–100) cm long, erect or ascending, but often weak and reclining on surrounding vegetation at maturity, unbranched or more commonly branched from the base, sparsely pubescent with stinging hairs, otherwise glabrous. Stipules 1–4 mm long, oblong to narrowly oblong or linear. Leaf blades 1–8 cm long, noticeably smaller toward the stem tip, narrowly ovate to ovate or somewhat heart-shaped, rounded to truncate or shallowly cordate at the base (those of the reduced upper leaves sometimes narrower and more or less angled at the base), the margins bluntly and relatively finely toothed, the surfaces sparsely to moderately short-hairy, the upper surface (rarely also the undersurface) also with scattered stinging hairs along the main veins, the undersurface sometimes purplish-tinged; cystoliths rounded or short-linear. Inflorescences shorter than the subtending petioles, small, globose clusters, these sometimes appearing as short, dense, spikelike racemes, the staminate and pistillate flowers mixed in the same inflorescence. Pistillate flowers with the 2 smaller sepals 0.4–0.8 mm long, linear, the 2 larger sepals 1.4–2.0 mm long, ovate. Fruits 1.0–1.5 mm long. 2n=26. April–September.

Uncommon in southwestern and southeastern Missouri (eastern [mostly southeastern] U.S. west to Kansas and Texas; Mexico). Banks of streams and rivers, bottomland forests, bases of bluffs, and less commonly sand savannas; also railroads and moist disturbed areas.

This species routinely occurs in shaded bottomland sites (Woodland et al., 1976), but in the sandy soils of the Sikeston Ridge in the northern portion of the Mississippi Lowlands Division it rarely may be found in association with a more upland flora.