9. Amaranthus palmeri S. Watson

Pl. 197 c, d; Map 818

Plants dioecious. Stems 30–100(–150) cm long, erect or ascending, glabrous (rarely hairy elsewhere), unarmed. Leaves mostly long-petiolate. Leaf blades 1–10 cm long, lanceolate to elliptic or ovate, narrowed or short-tapered to a bluntly or sharply pointed tip, rounded or narrowed at the base, glabrous. Inflorescences dull or dark green, axillary and terminal, the axillary inflorescences mostly elongate spikes, the terminal inflorescence a panicle with few to numerous ascending branches, the tip often somewhat curved or nodding at maturity, the main axis and branches glabrous or nearly so. Bracts 4–6 mm long, slightly to more commonly conspicuously longer than the sepals, narrowly ovate to ovate, tapered to a sharply pointed tip, with a somewhat thickened green midrib and relatively broad, thin, papery margins, the midrib extending beyond the main body as a conspicuous, spinelike awn. Staminate flowers with 5 sepals, these lanceolate to oblong-elliptic, erect or very slightly outward-curved, the inner ones 2.5–3.0 mm long, bluntly pointed or often minutely notched at the tip and with the midrib extending only slightly as a minute, sharp point, the outer ones 3.5–4.0 mm long, narrowed or tapered to a sharply pointed tip, the midrib extending beyond the main body as a short, spinelike awn. Stamens 5. Pistillate flowers with 5 sepals, these outward-curved at the tip, the inner ones 2–3 mm long, oblanceolate to spatulate, rounded or bluntly pointed at the tip, the midrib not or only slightly extending beyond the main body as a minute, sharp point, the outer ones 3–4 mm long, sharply pointed at the tip, the midrib extending beyond the main body as a short, spinelike awn. Stigmas 2(3), spreading. Fruits 1.5–2.2 mm long, circumscissilely dehiscent at about the midpoint, the surface somewhat wrinkled when dry. Seeds 1.0–1.3 mm in diameter, rounded along the rim, the surface reddish brown to black. 2n=32, 34. July–October.

Introduced, scattered sporadically mostly in the southern half of the state (native of southwestern U.S. east to Oklahoma and Louisiana, Mexico; introduced eastward and northward to Massachusetts and Florida, Canada). Fallow fields, margins ofcrop fields, railroads, roadsides, and open, disturbed areas, frequently in sandy soils.