Ordeb 156.— GRAMINE^E. 783 



13 P. Digitaria Poir. Mostly glabrous ; culm erect from an inclined base, 1 to 

 2^f bigh; lvs. lance-linear, flat, 6 to 16' by 5 to 8", on long sheatba; spikes a 

 pair, oonjugate, 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 

 fiexuous rachis. — (T) ? 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 ciliato ; 

 sheaths compressed; spikes usually 3, approximate (the 2 highest paired), very 

 slender; rachis fiexuous, triquetrous; spikelets lanceolate, 2-rowed, whitish, 

 1" long, close-pressed, gl. and pale scarcely longer than the flowers. — (X)Wet 

 places, Ga. Fla. to La. 



15 P. conjugatum Berg. Nearly glabrous and erect, 1 to 2f, 6lender; 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 internode, 

 very slender, 2 to 3' long; rachis nearly as wide as the 2 rows of minute ($" long), 

 round-ovate, acute, white, ciliate spikelets. — ® "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 2-V long; rachis narrower than the 



2 rows of ovate, acuminate (lj" long), glabrous spikelets. — 11 "Wet grounds, S. States. 

 p. tristachum. Spikes in 3s, closely approximate. 



17 P. ambfguum 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, §" long, gl. and pale about 

 equal, not longer than the purpUsh 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 ivith white soft hairs, the former lance-linear, slwrt, 

 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 {\") ; spikelets all pedicellate, 

 in 2s; gl. a fourth as long as the striate pale, and flower. — (I) 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 de- 

 cumbent at base, radiating and branching at the lower joints, 1 — 2f; lvs. linear- 

 lanceolate, on long, loose sheaths, softly pilous, the sheaths strigously hairy ; spikes 

 3 — 5' long, fascinate at the top of the stem, 5 to 9 together; spikelets in pairs, 

 oblong-lanceolate, closely appressed to the fiexuous rachis, in 2 rows, glume -J- as 

 long as the flower. — J) 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 fiexuous ; spikelets in Bs, all pedicellate ; glume soli- 

 tary, as long as the pale (abortive flower). — (J) Dry, gravelly soils, N. Y. to Ky. 

 Aug. (Panicum, L. Digitaria, MuhL) 



21 P. interruptum. Culm strictly erect, wiry, tall (2 to3f); lvs. long, linear, 8 

 to 15' by 3 to 4", clothed with copious soft hairs, as well as the sheaths; spikes 



3 or 4, raceme-like, 2 to 6' long, the spikelets ovate, acutish, in remote pairs dis- 

 tinctly pedicellate, rachis filiform. — Dry soils, La. and Tex. (Hale). (P. racemosum 

 Nutt. nee Jacq.) The inflorescence is almost paniculate. 



16. MIL'LIUM, L. Millet Grass. (Probably from the Latin milk, 

 a thousand, on account of its fertility.) Spikelets 1 -flowered, not articu- 

 lated with their pedicels ; glumes 2, without involucre or awns ; pales 

 2, shorter than the glumes, awnless, oblong, concave, persistent and car- 

 tilaginous, coating the caryopsis. (Comparing Millium with Panicum, 

 it appears that the 2 glumes of the former are, in fact, a glume, and a 



