Paspalum. GRAMINE^E. 257 



54. Festuca. Lower palet rounded on the back, few-nerved, pointed or awned at tip. Spikelets 



flattish. Ovary mostly smooth. 



55. Bromus. Lower palet convex or keeled on the back, 5 - 9-nerved, mostly awned below the 



2-cleft tip. Ovary pubescent, obtuse. 



56. Ceratochloa. Lower palet much compressed, entire, pointed or awned. Spikelets flattened. 



Ovary pubescent, with three horns at top. 



Subtribe VII. HORDEACEJL Spikelets 1 - several-flowered, sessile in alternate notches on 

 the opposite sides of a zigzag rhachis, either solitary or several together. Glumes entire, 

 awned or unawned. 



* Spikelet single (2 in one Lepturus) at each joint of the rhachis. 



57. Lepturus. Spikelet single, 1-flowered, almost imbedded in the notches of the slender 



rhachis. Slender spike usually solitary, or with a second pedicelled spikelet. 



58. Lolium. Spikelets many-flowered, placed with the edge next to the rhachis. Glume 1 (ex- 



cept iu the terminal spikelet), the inner one next to the rhachis lacking. 



59. Triticum. Spikes 3 - several-flowered, placed flatwise on the rhachis, both glumes present, 



standing right and left. 



* * Spikelets 2 or more at each joint of the rhachis. 

 +- Glumes anterior, forming a sort of involucre for the cluster of spikelets. 



60. Hordeum. Spikelets 1-flowered, in threes at each joint ; lateral spikelets usually sterile. 



61. Elymus. Spikelets 1 -several-flowered, 2 to 4 at each joint, all perfect and similar. 



+- + Glumes none, or 1 or 2 awn-like rudiments in their place. 



62. Gymuostichum. Spikelets few-flowered, somewhat pedicelled, 1 to 3 at each joint. 



1. PASPALUM, Linn. PASPALUM. 



Spikes or racemes solitary, either few and digitate or many and panicled. Spike- 

 lets in two to four rows upon one side of a flattened or filiform jointless rhachis, 

 jointed upon their short pedicels, plano-convex, awnless, apparently one-flowered. 

 Glumes two, nearly equal, few-nerved. Palets two, roundish or ovate, coriaceous, 

 the outer large, convex and enclosing the smaller flattened upper one, rarely mucro- 

 nate or with a few minute hairs at the apex. Scales 2, wedge-shaped or quadrate, 

 emarginate. Stamens 3. Ovary oblong, smooth : styles elongated ; stigmas hairy. 

 Grain enclosed in the hardened palets. 



A large mostly tropical genus of no agricultural value, of which 20 or more species occur in the 

 older States, though but one has thus far been detected on the Pacific Coast. The spikelets are 

 apparently one-flowered, but they are properly two-flowered with the lower glume suppressed, 

 while what appears as the lower glume is the lower palet of a lower floret, the upper palet of which 

 is wanting. In some species the lower glume is present as a minute scale. 



1. P. distichum, Linn. Culms from a strong perennial widely creeping root- 

 stock, 6 to 1 2 inches high, and clothed below by the somewhat crowded sheaths : 

 leaves flat, linear-lanceolate, 2 to 3 inches long, glaucous, rough above and with the 

 sheaths smooth or hairy : spikes two (rarely three or four), spreading, one sessile and 

 the other pedicelled, 1 to 1| inches long, densely flowered; spikelets in two rows, 

 ovate, acute, 1^ lines long: glumes 3-nerved, more or less pubescent. P. vagi- 

 natum, Swartz ; Trin. Sp. Gram, i, t. 120; Doell, Fl. Bras. ii 2 . 75. Panic urn puly- 

 rhizum, Presl, Eel. H.enk. i. 296. 



San Diego (Parri/) ; Los Angeles (Ncviii) ; Clear Lake (Bolandcr) ; also in Oregon and com- 

 mon in the Southern Atlantic States. Widely distributed in both the Old and New World and 

 in Australia. The appearance of the plant is greatly modified by the locality. The rootstock, 

 sometimes as large as the little finger, often runs just below the surface for many feet ; in sands, 

 the ascending stems are clothed with sharp-pointed scales (undeveloped sheaths), and have only 

 a.few proper leaves at the top. In some cases the elongation of the stem is arrested, probably by 

 being injured by some insect, and only the sheath is produced as a broad scale. When this occurs 

 at the base of the stem, the rootstock appears as if it bore scaly bulbs, like those of some small 

 lily. It is oftener near the top of the stem, which looks as if it were terminated by a small cone. 



A fragment of a Paspalum in the Torrey herbarium is marked "709, Coulter, California." 

 There is probably an error as to the locality, as no other collector has met with it. 



