Tufted grasses, with narrow flat leaf-blades and long slender spikes arranged in an open panicle, or rarely only one terminal spike. Spikelets several-flowered, narrow, sessile or shortly pedicelled, erect. Two lower scales empty, membranous, keeled, acute, unequal; flowering scales 1-3-nerved, 2-toothed and mucronate or short-awned between the teeth. Palet hyaline, 2-nerved. Stamens 3. Styles distinct. Stigmas plumose. Grain free, loosely enclosed in the scale and palet. [Greek, referring to the 2-toothed flowering scales.]

About 15 species, natives of the warmer regions of both hemispheres. Besides the following species, about 6 others occur in the southern and western parts of North America. Type species: Festuca fascicularis Lam.

Awn less than 1/3 as long as the flowering scale.

Spikelets 2"-4" long, the flowering scales acute or obtuse at the 2-toothed apex, lateral nerves

often excurrent.

1.

D.

fascicularis.

Spikelets 5"-6" long, the flowering scales acuminate at the usually entire apex, the lateral nerves

rarely excurrent.

2.

D.

acuminata.

Awn l/2 as long as the flowering scale or more.

3.

D.

maritima.

1. Diplachne Fascicularis (Lam.) Beauv. Salt-Meadow Diplachne. Clustered Salt-Grass. Spike-Grass

Fig. 567

Festuca fascicularis Lam. Tabl. Encycl. 1: 189.

1791. Diplachne fascicularis Beauv. Agrost. 160. 1812.

Culms 1°-2 1/2° tall, erect, ascending, or rooting at the lower nodes, finally branched, smooth and glabrous. Sheaths shorter than the internodes, loose, smooth or rough, the upper one longer and enclosing the base of the panicle; ligule 1"-2" long; blades 3'-8' long, 1"-1 1/2" wide, scabrous; panicle 4'-12' in length, often exceeded by the upper leaf, the branches erect or ascending, the lower 2'-5' long; spikelets 8-10-flowered, 2"-4" long; lower scales glabrous, rough on the keel; flowering scales, exclusive of the awn, 1 1/2"-2" long, the midnerve extending into an awn 1/2" long or less.

In brackish marshes, Florida to Texas, and up the Mississippi to Illinois and Missouri. Also in the West Indies. Aug.-Oct.

1 Diplachne Fascicularis Lam Beauv Salt Meadow Dip 567

2. Diplachne Acuminata Nash. Sharp-Scaled Diplachne

Fig. 568

D. acuminata Nash, in Britt. Man. 128. 1901.

Culms tufted, 1°-2° tall, finally branching; blades erect, 4'-1° long, 2 1/2" wide or less, usually involute when dry, very rough; racemes numerous, erect or ascending, the larger 3'-6' long; spikelets 5"-6" long, the scales 8-11, the flowering scales 3"-3 1/2" long, acuminate at the entire or occasionally slightly 2-toothed apex, the lateral nerves rarely slightly excurrent, the midnerve extending into an awn 3/4" long or less.

Wet or moist soil, Arkansas and Missouri to Nebraska and Colorado. June-Aug.

2 Diplachne Acuminata Nash Sharp Scaled Diplachne 5682 Diplachne Acuminata Nash Sharp Scaled Diplachne 569

3. Diplachne Maritima Bicknell. Long-Awned Diplachne

Fig. 569

Festuca procumbens Muhl. Gram. 160. 1817. Diplachne procumbens Nash, in Small, Fl. SE. U. S. 145.

1903. Not Arech. 1896. D. maritima Bicknell, Bull. Torrey Club 35: 195. 1908.

Culms tufted, finally branching, 8'-16' tall; blades erect, 3'-8' long, 2" wide or less, involute when dry; racemes numerous, erect, the larger 2'-3' long; spikelets about 5" long; scales 8-10, the empty ones usually awned or awn-pointed, the flowering scales, exclusive of the awn, 2 l/4"- 4 1/2" long, acuminate at the slightly 2-toothed apex, the midnerve extending into an awn 1/2 or more as long as the scale.

Brackish marshes and shores, Massachusetts to South Carolina; also on the shore of Onondaga Lake, N. Y. Aug.-Oct.