A. retrofléxus, L. Roughish and more or less pubescent; leaves dull green, long-petioled, ovate or rhombic-ovate, undulate; the thick spikes crowded in a stiff or glomerate panicle; bracts awn-pointed, rigid, exceeding the acute or obtuse sepals.—Cultivated grounds, common; indigenous southwestward. (Adv. from Trop. Amer.)
A. chloróstachys, Willd. Very similar, but smoother and deeper green, with more slender, linear-cylindric, more or less flexuous spikes, the lateral ones spreading or divaricate, and the sepals more frequently acute or acuminate. (A. retroflexus, var. chlorostachys, Gray.)—Cultivated grounds; apparently also indigenous southwestward.—Var. hýbridus, Watson, is similar, but smooth and still more loosely panicled. (A. retroflexus, var. hybridus, Gray.) (Adv. from Trop. Amer.)
[*][*] Flowers crowded in close and small axillary clusters; stems low, spreading or ascending; stamens and sepals 3, or the former only 2.
1. A. álbus, L. (Tumble Weed.) Smooth, pale green; stems whitish, erect or ascending, diffusely branched; leaves small, obovate and spatulate-oblong, very obtuse or retuse; flowers greenish; sepals acuminate, half the length of the rugose fruit, much shorter than the subulate rigid pungently pointed bracts; seed small, {2/3}´´ broad.—Waste grounds, common.
2. A. blitoìdes, Watson. Like the last, but prostrate or decumbent; spikelets usually contracted; bracts ovate-oblong, shortly acuminate; sepals obtuse or acute; fruit not rugose; seed about 1´´ broad.—From Minn. to Mo. and Tex., and westward, and introduced eastward as far as western N. Y.
A. Blìtum, L., resembles the last, but is usually erect, with shorter and more scarious bracts, and a smaller seed more notched at the hilum.—Near N. Y. City and Boston. (Adv. from Eu.)
§ 2. Utricle thinnish, bursting or imperfectly circumscissile; flowers monœcious.
A. spinòsus, L. (Thorny Amaranth.) Smooth, bushy-branched; stem reddish; leaves rhombic-ovate or ovate-lanceolate, dull green, a pair of spines in their axils; upper clusters sterile, forming long and slender spikes; the fertile globular and mostly in the axils; flowers yellowish-green, small.—Waste grounds, N. Y. to E. Kan., and southward. (Nat. from Trop. Amer.)
§ 3. EÙXOLUS. Utricle rather fleshy, remaining closed or bursting irregularly; no spines; bracts inconspicuous.
3. A. pùmilus, Raf. Low or prostrate; leaves fleshy and obovate, emarginate, strongly nerved; flower-clusters small and axillary; stamens and sepals 5, the latter half the length of the obscurely 5-ribbed fruit.—Sandy beaches, R. I. to Va.