15. Sporobolus Cryptandrus (Torr.) A Gray. Sand Dropseed

Fig. 478

Agrostis cryptandra Torr. Ann. Lye. N. Y. 1: 151. 1824. Sporobolus cryptandrus A. Gray, Man. 576. 1848.

Culms 1 1/2°-3 1/2° tall, erect, simple or sometimes branched at the base, smooth and glabrous. Sheaths smooth, with a dense pilose ring at the summit, the lower short, crowded and overlapping, the upper much longer, generally enclosing the base of the panicle; ligule a ring of short hairs; blades 3'-6' long, 1"-2" wide, flat, glabrous beneath, scabrous above, long-acuminate; panicle 6'-10' in length, the base generally included in the upper sheath, rarely entirely exserted, the branches spreading or ascending, alternate, the lower 1 1/2'-3' long; spikelets 1"-1 1/4" long, the scales acute, glabrous, the outer scabrous on the keel, the lower one-third as long as the upper; third scale somewhat longer or shorter than the second.

In sandy soil, Massachusetts to Montana, Pennsylvania and Mexico. Prairie-grass. Aug.-Oct.

16. Sporobolus Heterolepis A. Gray. Northern Dropseed

Fig. 479

Vilfa heterolepis A. Gray, Ann. Lye. N. Y. 3: 233. 1835. Sporobolus heterolepis A. Gray, Man. 576. 1848.

Culms 1°-3° tall, erect, simple, smooth and glabrous. Sheaths sometimes sparingly pilose at the summit, the lower short, loose, and overlapping, the upper much elongated and tight to the culm; ligule a ring of short hairs; blades involute-setaceous, glabrous, the margins and upper part of the midrib very rough, the basal about three-fourths the length of the culm, occasionally equalling it, those of the culm shorter; panicle 3'-10' in length, its branches erect or ascending, alternate or sub-verticil-late, the lower 1 1/2' - 3 1/2' long; spikelets 2"-2 3/4" long, the scales smooth and glabrous, the outer unequal, acuminate, the lower subulate, about half the length of the broad second one, often awn-pointed; third scale obtuse or acute, shorter than the second or occasionally equalling it.

In dry soil, Quebec to Saskatchewan, south to Connecticut, Pennsylvania, Missouri and Texas. Bunch-grass. Aug.-Sept.

17. Sporobolus Texanus Vasey. Texas Drop-Seed

Fig. 480

S. texanus Vasey, Contr. U. S. Nat. Herb. 1: 57. 1890.

Culms 1°-2° tall, branching below; sheaths crowded, the lower ones papillose-hirsute; blades erect, firm, 1 1/2'-6' long, 1 1/2"-2 1/2" wide, smooth beneath, very rough above; panicle included at the base, the upper branches finally widely spreading, 2'-4' long; spikelets a little exceeding 1" long, on long slender pedicels; scales smooth and glabrous, the first scale narrow, acuminate, less than 1/2 as long as the second which equals the third scale.

In dry places, Kansas to Mexico. July-Sept.