2 to 4' long, alternate, suberect, pilous at base; spikelets large (1 1/4' diam.), in

3 rows on the narrow, flexuous rachis. -Order CLVI Gramineae Grasses Part 8 2507 Car. to Fla. and La.

8 P. tenue Kunth. Glabrous; culm erect, very slender; lvs. narrow, very long, ciliate on the margins, sheath ciliate; spikes 4 or 5, very slender, alternate, spreading, hairy at base; spikelets orbicular, in 3 rows; rachis flexuous, narrow, the teeth 2-flowered. -Order CLVI Gramineae Grasses Part 8 2508 N. J. to Ga. (Le Conte). Differs from No. 5, in its ciliate lvs. and 3-nerved spikelets.

9 P. ariuidinaceuni Poir. "Glabrous; lvs. somewhat sword-shaped (com-pressed-carinate), the margin scabrous; spikes alternate, elongated; spikelets in 3 rows gls. (gl. and pale) equal, obtuse. - Carolina." Poiret.

10 P. praecox Walt. Glabrous throughout; culm erect; lvs. lance-linear, very long; spikes 3 to 5, alternate, dense-flowered, with a tuft of long hair at base; rachis linear, straight (not flexuous), narrower than the 3 rows of very smooth, orbicular, compressed spikelets; gls. 3-veined. -Order CLVI Gramineae Grasses Part 8 2509 Wet places, Car. to Fla. May. - Aug. (P. lentiferum Lam.)

11 P. fluitans Kunth. Culm decumbent and ascending 10 to 20', generally floating; lvs. scabrous, lance-linear, 2 to 5' by 4 to 6'; sheaths inflated, open, ciliate at base; spikes 20 to 50, 1 to 2 1/2' long, the lower somewhat verticillate; rachis foliaceous, nearly I" broad, covering the 2 rows of ovate, acute spikelets and projecting in a point beyond them. -Order CLVI Gramineae Grasses Part 8 2510 River swamps, S. Ill to Va. and S. States*. Oct (P. mucronatum Muhl. Ceresia, Ell.)

12 P. Walterianuni Schult. Culm decumbent, branching, ascending; lvs. glabrous, lance-linear, 2 to 4' by 3 to 5"; sheaths open, all glabrous; spikes 2 or 3 on each branch, 1 to 2' long; rachis very broad (near 2"), covering the 2 rows of oval, acute spikes but not projecting beyond them. -Order CLVI Gramineae Grasses Part 8 2511 Wet soils, Car. to Fla. and La. Jl. - Sept. (P. vnginutum Ell.)

13 P. Digitaria Poir. Mostly glabrous; culm erect from an inclined base, 1 to 2 1/2f high; lvs. lance-linear, flat, 6 to 16' by 5 to 8", on long sheaths; spikes a pair, conjugate, slender, 2 to 4' long, at top of the long naked ped. or upper inter-node of culm; spikelets lanceolate, in 2 opposite rows on the vertically compressed (lexuous rachis. -Order CLVI Gramineae Grasses Part 8 2512 ? Damp pine woods, Va. to Fla and La. (Millium paspa-loides Ell P. Michauxiana Kth.)

14 P. tristachyuni Le Conte. Glabrous, decumbent below, 12 to 20' high; culm filiform above; lvs. linear, flat, 3 to 8' by 2 to 3", margins sparingly ciliate; sheaths compressed; spikes usually 3, approximate (the 2 highest paired), very slender; rachis flexuous, triquetrous; spikelets lanceolate, 2-rowed, whitish. 1" long, close-pressed, gl and pale scarcely longer than the flowers. -Order CLVI Gramineae Grasses Part 8 2513 Wet places, Ga. Fla. to La.

15 P. conjugatum Berg. Nearly glabrous and erect, 1 to 2f, slender; lvs. broadly linear, 2 to 4' by 2 to 4", on compressed sheaths; upper sheath very long and nearly leafless; spikes 2, a conjugate pair, on the filiform upper interuode, very slender, 2 to 3' long; rachis nearly as wid6 as the 2 rows of minute (1/2" long), round-ovate, acute, while, ciliate spikelets. -Order CLVI Gramineae Grasses Part 8 2514 Waste places about N. Orleans (Hale).

16 P. distichum L. Nearly glabrous; culms some inclining at base, 12 to 18 high; lvs. lance-linear, bearded at the throat, 2 to 3' by 2 to 3"; spikes 2, a pair nearly or quite conjugate, dense-flowered, 1 to 24 1/2' long; rachis narrower than the

2 rows of ovate, acuminate (1 1/2" long), glabrous spikelets. -Order CLVI Gramineae Grasses Part 8 2515 Wet grounds, S. States. β. TRISTACHUM. Spikes in 3s, closely approximate.

17 P. ambiguum DC. Glabrous; culms clustered, decumbent, 8 to 15' high; lvs. lance-linear, shorter than the sheaths (2 to 4' by 2 to 4"); spikes 2 to 4, about 2' long, slender; spikelets crowded, 2-rowed, ovate, 2/3" long, gl and pale about equal, not longer than the purplish flower, both hairy. - Sandy fields, especially South. Often purplish. Aug., Sept. § Eur. (Panicum glabrum Gaud.)

18 P. serotinum Fluegge. Decumbent, creeping and rooting, with upright branches; lvs. and sheaths villous with white soft hairs, the former lance-linear, short, about 1' by 2"; spikes digitate, about in 5s, slender, 2 to 3' long; rachis flat, about as wide as the 2 rows of elliptical spikelets (1/2"); spikelets all pedicellate, in 2s; gl. a fourth as long as the striate pale, and flower. -Order CLVI Gramineae Grasses Part 8 2516 Sandy fields, Car. to Fla. and La. Forms a dense carpet. Jl. - Oct (Digitaria villosum Ell.)

19 P. sanguinale Lam. Purple Finger Grass. Crab Grass. Culms decumbent at base, radiating and branching at the lower joints, 1 - 2f; lvs. linear-lanceolate, on long, loose sheaths, softly pilous, the sheaths strigously hairy; spites 3 - 5' long, fascinate at the top of the stem, 5 to 9 together; spikelets in pairs, oblong-lanceolate, closely appressed to the flexuous rachis, in 2 rows, glume 1/2 as long as the flower. -Order CLVI Gramineae Grasses Part 8 2517 Common in cultivated grounds, N. Eng., W. Ind. Aug. - Oct. (Panicum, L. Digitaria, Scop.)

20 P. filiforme Swartz. Culm erect, filiform, simple, 12 - 18'; lvs. short, nearly smooth, narrow-lanceolate; lower sheaths very hairy, upper glabrous; spikes 2 - 4, filiform, erect; rachis flexuous; spikelets in 3s, all pedicellate; glume solitary, as long as the pale (abortive flower). -Order CLVI Gramineae Grasses Part 8 2518 Dry, gravelly soils, N. Y. to Ky. Aug. (Panicum, L. Digitaria, Muhl)