3. Setaria italica (L.) P. Beauv. (foxtail millet, common millet)

Pl. 174 d, e; Map 704

S. viridis (L.) P. Beauv. ssp. italica (L.) Briq.

Plants annual, with soft bases, without rhizomes. Flowering stems 35–120 cm long, rarely slightly flattened, glabrous or less commonly hairy at the nodes. Leaf sheaths rounded on the back to slightly keeled, hairy along the margins and roughened or somewhat hairy on the surface, the ligule 1.0–2.5 mm long. Leaf blades 6–35 cm long, 5–20 mm wide, flat, the surfaces roughened or less commonly glabrous. Inflorescences 3–20 cm long, erect or somewhat nodding or drooping toward the tip, the short branches often slightly elongate and appearing relatively dense, but distinct (the inflorescence thus appearing somewhat lobed), not in well‑defined whorls, the main axis with short, soft, upwardly pointing hairs and often also with longer, soft, ascending to spreading hairs, the spikelets subtended by 1–3 green, brown, or purple bristles, these 3–12 mm long. Spikelets 2.6–3.4 mm long, disarticulating below the fertile floret, leaving the persistent glumes, sterile floret, and bristles attached to the main axis. Lower glume 0.8–1.4 mm long. Upper glume 2.0–2.6 mm long. Lowermost floret usually sterile, 2.2–3.0 mm long. Fertile floret with the lemma 2.2–2.8 mm long, the surface smooth and shiny. Anthers 0.5–0.9 mm long. 2n=18. July–October.

Introduced, scattered nearly throughout Missouri (presumably originally a native of Europe and Asia; cultivated in tropical and warm‑temperate regions nearly worldwide and escaped sporadically throughout its range). Banks of streams; also pastures, fallow fields, crop fields, roadsides, railroads, and open, disturbed areas.

This species has a long history of cultivation in the Old World, where it has been recorded from archaeological excavations of Stone Age dwellings (Rominger, 1962). It is thought to have been derived by human selection from a wild ancestor much like S. viridis. In parts of Asia, it is cultivated as a grain crop for human food, but its principal use is for animal fodder, in the form of both hay and grain. In the United States, S. italica is cultivated most commonly in the Great Plains. A large number of cultivars have been developed, based on different selections of various characters, including degree of inflorescence branching, fruit color and size, and bristle color and length. This has led to a complex infraspecific nomenclature (Hubbard, 1915) that is not reviewed here. Also, a large number of common names are in use for these cultivated variants, including “foxtail millet,” “German millet,” “Hungarian millet,” and “Italian millet.” It is sometimes referred to as “Japanese millet,” but that name may lead to confusion with Echinochloa crusgalli. Similarly, the name “common millet” may lead to confusion with Panicum miliaceum.