14. ORYZOP'SIS, Mx. Mountain Rice. (Gr. rice, appearance.) Spikelets 1-flowered; glumes membranous-bordered, veined, subequal, and about equaling the oblong, terete, deciduous, short-stiped flower; lower pale coriaceous, involute, inclosing the caryopsis and tipped with a simple, jointed awn; scales linear-oblong. - Fls. in a slender or spike-like panicle.
§ Sheaths, all leaf-bearing. Stip of the flower nearly glabrous, very short.............................
§ Sheaths, at least the upper, leaflesss Stipe conspicuously bearded...............
Nos. 2, 3
1 O. melanocarpa Muhl. Culm erect, simple, leafy, 18 - 24'; panicle simple, flexuous, few-flowered; spikelets racemous, ovoid-lanceolate; glumes acuminate, mucronate, 5 - 6" in length, smooth; pales hairy, nearly black when ripe, the lower one tipped with an awn an inch in length; fruit black. - Rocky hills, U. S and Can., frequent. Aug. (Piptatherum nigrum Torr.)
2 O. asperifolia Mx. Culm nearly naked, purple at base, 10 - 20'; lvs. subrad-ical, erect, rigid, pungent at the point, nearly as long as the stem, cauline ones few and very short; spikelets in a racemous, simple, flexuous panicle, 2 to 4' long, 1 - 2 upon each branch; glumes abruptly acuminate; pales white, the lower one with a long, bent awn. - Woods, N. States N. to Subarctic Am. Leaves green through the winter. Caryopsis white, about as large as rice, farinaceous. May. (Urachne Trin.)
3 O. Canadensis Torr. Culms slender, 9 to 18' high, naked above; lower sheaths bearing rigid, involute-filiform lvs.; pan. 1 to 2' long, narrow, the branches mostly in pairs; gls. often purplish, 1 to 2" long; pales white, bearded with whitish hairs, the awn short and deciduous or wanting. - Rocky woods, N. Eng.. to the shores of L. Superior. May. (Stipa juncea Mx., nec L. S Canadensis Poir. Urachne Trin. Milium pungens Torr.)
15. PAS'PALUM L. (Gr. millet; from the resemblance of the seeds.) Spikelets plano-convex, in unilateral spikes; glumes (apparently) 2, membranous, equal, ovate or orbicular, closely pressed to the fertile flower; stigmas plumous, colored; caryopsis coated with the smooth, coriaceous pales. (But theoretically, the lower glume is obsolete and its place supplied by the empty pale of an abortive flower. In Nos. 19 and 20 the lower glume appears, under a lens, as a mere rudiment.) - Spikes linear, the fls. in 2 or 4 rows; rachis not jointed; pedicels articulated.
§ Paspalum. Spikelets suborbicular, obtuse, crowded. Spikes alternate. (*)
* Spikes many (7 to 30), with the spikelets mostly 4-rowed.................................
Nos. 1, 2
* Spikes few (1 to 3), mostly solitary, slender (1" wide), 2 or 3-rowed.......
* Spikes few (2 to 6) - with the spikelets in 3 rows, near 3" wide................................
Nos. 4, 5
- with the spikelets in 3 rows, near 3" broad, (a)
a Leaves very hairy. Culms decumbent....................
a Leaves only ciliate on the margins...............................
Nos. 7, 8
a Leaves very glabrous, margins scabrous......................
Nos. 9, 10
§ DIGITARIA. Spikelets ovate or lanceolate, acute. Spikes mostly digitate. (**)
** Rachis leaf-like, broader than the 2 rows of spikelets beneath it...........................
Nos. 11, 12
** Rachis narrow, triquetrous or flat, with the spikelets close-appressed. (b)
b Glumes (glume and pale) about equal, as long as the flower, (e)
c Spikelets lanceolate. Spikes in pairs or threes..........................
Nos. 13, 14
c Spikelets ovate. Spikes in pairs or threes...................................
Nos. 15 - 17
b Glume scarce half as long as the pale. Spikes 5 to 12, clustered..........
Nos. 18, 19
* Rachis filiform with the spikelets loose and subremote.......................................
Nos. 20, 21
1 P. virgatum L. Culms decumbent at base, glabrous, 18 to 30'; lvs. broad-linear, rough-edged, 12 to 18' by 5 to 6"; sheaths glabrous, with a hairy throat; spikes numerous (7 to 12): rachis straight (not flexuous), flat, narrower than the 4-rowed, dense, orbicular, obtuse spikelets. - Moist soils, S. States, common in the low country. Jl. - Oct. - A very smooth variety is the P. confertum Le Conte.
β. purpurascens. Culm below, lvs. and sheaths dark purple. (P. purpu-rascens Ell.)
2 P. undulatum Poir. "Plant very glabrous; lvs. long and linear, somewhat carinate; margin scabrous, base ciliate, sheaths glabrous; spikes many; rachis flat, glabrous, margins scabrous, narrower than the 2 to 4-rowed spikelets; lower glume pubescent, upper glume (palea) smooth, transversely plaited near the margins.)" Kunth. Ga. ar.d Fla. A variety of No. 6 ? (P. plicatum Mx.)
3 P. aetaceum Mx. Culm ascending from a decumbent base, very slender, 1 to 2f with very remote joints; lvs. lance-linear, 3 - 7' by 2 - 3 , ciliate and soil hairy; sheaths pubescent, upper one very long; spike generally solitary, often 2, on a long, very slender peduncle, sometimes with another scarcely exserted from the sheaths; spikelets plano-convex, with the flat side out, 3/4" diam., 1 or 2 on each very short pedicel, appearing 2 - 3-rovved in the 1-sided spike. - Dry fields, Mass. to I11. and S. States. Aug. (P. debile and ciliatifolium Mx.)
β. longipedunculatum. Larger, less hairy, and spikelets evidently 3-rowed. - S. States. (P. longip. LeC.)
4 P. laeve Mx. Culm erect, rather firm, 18' - 3f, glabrous; lrs. generally smooth, pilous only at the base, broadly linear; lower sheaths sometimes hairy, spikes 2 - 6, alternate, spreading, with a few long, white hairs at the base; spikelets in 2 rows; rachis flexuous, flat on the back; pedicels undivided, with one spikelet; spikelets twice as large (l 1/2" diam.) as in the preceding; glume orbicular-ovate. 3-veined. - Grassy banks of rivers, Conn, to Ind. and S. States. Aug. Quite variable, including several reputed species.
β. undulosum. Lvs. rather long and broad, with wavy-margins. (P. Lecontianum Schult.) γ. Floridanum. Spikelets enlarged (near 2 ' long), glume 5-veined. (P. macrospermum Flgg.) δ. altissimum. Strict and tall; sheaths much compressed. (P. altissimum LeC.)
5 P. angustifolium Le Conte. Culm erect, wiry, glabrous, 2f high; lvs. glabrous, narrowly linear, almost setaceous, compressed carinate, 9 to 18' long; sheaths long, smooth; spikes 2 or 3, alternate, divaricate, 1 to 2 long, with a few hairs at base; spikelets orbicular, 1' diam. in 2 rows, with a very narrow rachis. - Wet places, Ga., Fla. to La. A distinct species. Seeds blackish.
6 P. dasyphyllum Ell. Culm decumbent at base, 12 to 30' high, glabrous-, lvs. broadly linear, clothed with copious soft hairs as well as the long sheaths; spikes 2 to 4, large, spreading, the ped. slightly exserted from the upper sheath; spikelets oval, obtuse, large, in 3 rows; teeth of the rachis 2-flowered. - Dry fields, S. States, common. ? Jl. - Oct.
7 P. latifoliurn Le Conte. Glabrous; culm erect, stout, tall (2 to 3f), from a slightly decumbent base; lvs. flat, large, lance-linear, 6 to 12' by 5 to 10", margins ciliate; sheaths hairy at throat, shorter than the long internodes; spike3 2 to 4,