Ordeb 166.— GRAMINB^. 783 



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

 2-}f high; Ivs. lance-linear, flat, 6 to 16' by 6 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 

 Ilexuous rachis. — (J ? Damp pine woods, Va. to Fla. and La. (Millium paspa- 

 loides Ell. P. Michauxiana Kth.) 



14 P. trist^chyum Le Conte. Glabrous, decumbent below, 12 to 20' high; 

 culm filiform above ; Ivs. 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. — ©Wet 

 places, Ga. Fla. to La. 



15 P. conjugatum Berg. Nearly glabrous and erect, 1 (o 2f, slender; Ivs. 

 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 intemodo, 

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

 round-ovate, acute, white, ciliate spikelets. — (T) Waste places about N. Orleans 

 (Hale). 



16 P. distichum L. Nearly glabrous; culms seme inclining at base, 12 to 18' 

 high ; Ivs. 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|-' long; rachis narrower than the 



2 rows of ovate, acuminate (1 J" long), glabrous spikelets. — 2f "Wet grounds, S. Statea 

 /3. TBiSTACUUM. Spikes in 3s, closely approximate. 



17 P. ambf guiim DC. Glabrous ; culms clustered, decumhent, 8 to 15' high ; Ivs. 

 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, f" 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. serdtinum Pluegge. Decumbent, creeping and rooting, with upright 

 branches; Ivs. and sheaths villous with white soft hairs, the former \axice-\mea,T, short, 

 about V by 2" ; spikes digitate, about in .5s, slender, 2 to 3' long; rachis flat, 

 about as wide as tlio 2 rows of elliptical spikelets (-J") ; spikelets all pedicellate, 

 in 2s; gl. afourth as long as the striate pale, andflower. — ® Sandy fields, Car. to 

 Fla. and La. Forms a dense carpet. Jl. — Oct. (Digitaria villosum EU.) 



19 P. sanguinale Lam. Pukplb Fingkb Grass. Ceab Grass. (Mms de- 

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

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

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

 oblong-lanceolate, closely appressed to tho flexuous rachis, in 2 row.s g'ume i as 

 long as tlie flower.^ 3) Common in cultivated grounds, N. Eng., W. lud. Aug. — 

 Oct. (Panicum, L. Digitaria, Scop.) 



20 P. filiforme Swartz. Culm erect, filiform, simple, 12 — 18'; Ivs. short, nearly 

 smooth, uarrow-lanceolato ; lower sheaths very hairy, upper glabrous; spikes 

 2 — i^ filiform, erect ; rachis flexuous ; spilcelets in 3s, all pedicellate ; glume soli- 

 tary, as long as tho 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 to 3f ) ; Ivs. long, linear, 8 

 to 15' by 3 to 4", clothed with copious soft hairs, a,s 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 fiMform.— Dry soils. La. and Tex. (Hale). (P. racemosum 

 Nutt. nco Jacq.) Tho inflorescence is almost paniculate. 



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

 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 tho glumes, awnlcss, oblong, concave, persistent and car- 

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

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



