Tall grasses with stout horizontal rootstocks, elongated leaf-blades, which are involute at the apex, and paniculate inflorescence. Spikelets 1-flowered; rachilla not prolonged beyond the flower. Scales 3, 1-nerved, acute, the 2 outer unequal, empty; third scale longer or shorter than the second, a ring of hairs at its base; palet strongly 2-keeled. Stamens 3. Styles distinct. Stigmas plumose. Grain free. Seed adherent to pericarp. [Greek, a reed-like grass.]

Species 4 or 5 in the temperate and subtropical regions of North America. Type species: Arundo brevipilis Torr.

Flowering scale and palet glabrous.

1.

C.

longifolia.

Flowering scale and palet pubescent.

Spikelets 2"-2l/2" long; a plant of southern New Jersey.

2.

C.

brevipilis.

Spikelets 3 1/2"-4," long; a plant of the western United States.

3.

C.

gigantea.

1. Calamovilfa Longifolia (Hook.) Hack. Long-Leaved Reed-Grass

Fig. 513

Calamagrostis longifolia Hook. Fl. Bor. Am. 2: 241,

1840. C. longifolia Scribn. in Hack. True Grasses 113.

1890. Calamovilfa longifolia magna Scribn. & Merr. Circ.

U. S. Dep. Agr. Agrost. 35: 3. 1901.

Culms 2°-5° tall, erect, simple, stout, smooth and glabrous. Sheaths crowded and overlapping, glabrous or sometimes hairy; ligule a ring of hairs about 1" long; blades 8'-1° long or more; panicle generally narrow, often 1° long or more, commonly pale, the branches erect, or occasionally open with the branches somewhat spreading; spikelets 2 1/2" -3" long; scales acute, the first shorter than the second, the third glabrous, a little longer or shorter than the second, the copious basal hairs from 2/3 as long as to nearly equalling the scale; palet slightly shorter than the third scale.

In sandy places, western Ontario to Mackenzie, south to northern Indiana, Kansas and Colorado. Big Sand-grass. Carizzo. July-Sept.

1 Calamovilfa Longifolia Hook Hack Long Leaved Ree 513

2. Calamovilfa Brevipilis (Torr.) Hack. Short-Haired Reed-Grass. Purple Bent-Grass

Fig. 514

Arundo brevipilis Torr. Fl. U. S. 1: 95. 1824. Calamagrostis brevipilis Beck, Bot. North. & Mid. St. 401.

1833. Calamovilfa brevipilis Hack. True Grasses 113. 1890.

Glabrous and smooth or very nearly so, culms 2°-4° tall, erect, simple. Sheaths shorter than the internodes; ligule a ring of very short hairs; blades 6'-12' long, 1 1/2" wide or less, attenuate into a long slender involute tip, smooth beneath, slightly scabrous above; panicle open, 5'-10' in length, the branches ascending, the lower 2'-4' long; spikelets 2"-2 1/2" long; scales acute, scabrous toward the apex, the outer unequal, the first one-half as long as the second; third scale exceeding the second, pubescent on the lower half of the keel; basal hairs one-third the length of the scale; palet nearly equalling the scale, pubescent on the lower half of the keel.

In swamps, pine barrens of New Jersey. Aug.-Sept.

2 Calamovilfa Brevipilis Torr Hack Short Haired Re 5142 Calamovilfa Brevipilis Torr Hack Short Haired Re 515

3. Calamovilfa Gigantea (Nutt.) Scribn. & Merr. Giant Reed-Grass

Fig. 515

Calamagrostis gigantea Nutt. Trans. Am. Phil. Soc. II, 5: 143. 1837. Calamovilfa gigantea Scribn. & Merr. Circ. U. S. Dep.

Agr. Agrost. 35: 2. 1901.

A stout glabrous perennial with stout creeping rootstocks, rigid often involute leaf-blades, and large open panicle. Culms 3°-6° tall; leaf-sheaths exceeding the internodes; blades up to 1° long or more; panicle 1°-2 1/2° long, the spreading or ascending branches naked at the base, the longer up to 1° long; spikelets 3 1/2"- 4" long, the empty scales acute, the first shorter than the second, the third scale a little longer or shorter than the second scale, long-hairy on the back and keel, the basal hairs copious.

In sandy places, Kansas to Arizona.