GRASS FAMILY 83 



world, ill all latitudes and altitudes where ai'e found conditions suitable for 

 plant growth, but least abundant in dense tropical forests. 



Biblii.g. — Bentbam & Hooker, Gen. PI. 3: 1074. 1883. Hackel in Engler & Prantl, Pflan- 

 zenfam. 2": 1. 1887 (with .several supplements). The True Gra.sses, Seribner & Southworth. 

 1890 (a translation of the preceding). Boal, Grasses N. Am. 2 vols. 1896 (systematic portion 

 in seconil volume). For cultivated grasses see article on Gramineae in Bailey's Cyel. Agric. 

 and articles on individual genera in Bailey's Cycl. Hort.; also Farm Grasses of U. S. by Spill- 

 man, and various bulletins of the U. S. Dept. Agr. Div. Agrost., especially Bull. 14, Economic 

 Grasses. The following more recent articles or monographs include references to California: 

 Vasey, Ilhistr. N. Am. Grasses, Vol. 1, Grasses of the Southwest (U. S. Dept. Agr. Div. Bot. 

 Bull.' 12. in 2 pts. 1891); Vol. 2, Grasses of the Pacific Slope (op. cit. Bull. 13, in 2 pts. 

 1893). r. S. Dept. Agr. Div. Agrost. Bull. 4. 1897, including revision of Hordeum and 

 Agropyron, by Seribner & Smith; Bull. 7, American Grasses I, Bull. 17, American Grasses 

 II, Bull. 20, American Grasses III, the latter being an account of the genera of N. A. 

 grasses (all by Seribner); Bull. 11, 1898, including a revision of Calamagrostis by Kearney; 

 Bull. 18, 1899, a revision of Sitanion by J. G. Smith ; Bull. 21, 1900, a revision of Chaetochloa 

 by Seribner & Merrill; Bull. 23, 1900, a revision of Bromus by Shear. U. S. Dept. Agr. 

 Bur. PI. Ind. Bull. 9, 1902, a revision of Spartina by Merrill; Bull. 33, 1903, a revision of 

 Leptochloa by Hitchcock; Bull. 68, 190.J, a revision of Agrostis by Hitchcock. Contr. Nat. 

 Herb. Vol. 3, pp. 1-89. 1892, a Monograph of the Grasses of the United States by Vasey, 

 including the tribes Maydeae to Agrostideae; Vol. 10, pp. 1-48. 1906, a revision of Festuca 

 by Piper; Vol. 11, 1906, a Flora of the State of Washington by Piper; Vol. 14, pp. 343-428, 

 1912, the Grama Grasses by Grijfiths; Vol. 1.5, 1910, a revision of Panicum by Hitchcock & 

 Cha.se. Bolander, Genus Meliea in California (Proc. Gal. Acad. 4: 89-104. 1870), Cienus Stipa 

 in California (op. cit. 168-170. 1872). Seribner, Revision N. A. Melicae (Proc. Acad. Phila. 

 ISSf): 40-48. 188,5). 



Subfamily I. PANICOIDEAE. 



Spikelets with 1 perfect flower, or with a second staminate or neutral flower below. Rachilla 

 articulated below the glumes, the more or less dorsally compressed spikelets falling from 

 the pedicels entire, singly, in groups, or together with joints of an articulate rachis. 

 Spikelets in pairs (or the terminal in 3's) one sessile or nearly so and fertile, the other 



pediceled; lemmas hyaline Tribe I. Axdropocioxeae. 



Spikelets not in pairs (in certain genera spikelets paired but lemmas firmer than glumes). 

 Spikelets in groups at each joint of the main axis, falling off entire; outer glumes larger 



than the florets Tribe II. Zoysieae. 



Spikcdets not in groups, falling singly; outer or first glume smaller than the floret. 



Tribe III. P.vxiceae. 

 Subfamily II. POAt'OIDEAE. 



Spikelets 1 to many-flowered, the imperfect or rudimentary floret, if any, uppermost (or if 

 below the fertile one, the spikelet strongly laterally compressed) ; rachilla usually articulated 

 above the glumes, these persistent on the pedicel or rachis after the fall of the florets; spike- 

 lets more or less laterally compressed. The spikelets are articulated below the glumes in 

 Alopecurus, Cinna, Polypogon, Notholcus, Sphenopholis, Spartina and Beekmannia, but 

 these genera are distinguished from Subfamily I by the laterally compressed spikelets. 

 Spikelets more or less pediceled, in open or contracted panicles, these sometimes spike-like 

 but not 1-sided. 

 Spikelets with 1 perfect flower, with sometimes a pair of sterile or staminate florets below. 

 Spikelets witli 1 perfect terminal flower and a pair of sterile or staminate florets 



below, these sometimes reduced to minute bristles Tribe IV, Phalaride.\e. 



Spikelets 1-flowered, the rachilla sometimes prolonged behind the palea as a naked or 



plumose bristle Tribe A'. Aurostideae, 



Spikelets 2 to several-flowered. 



.\wn usually present, often twisted, borne on the back of the lemma or between the 

 teeth of the bifid apex (awnless in Sphenopholis and Koeleria); glumes usually 

 Iruiger than the first floret; rachilla ]>rol()nged lieliiiid the ])alea of the uppermost 



floret Tribe VI. Aveneae. 



.\\vn. when i)resei!t, terminal, usually straight (the apex of the lemma bifid in Bromus, 

 and in certain species of Festuca and Meliea) : glumes usually shorter than the 

 first floret Tribe VIII. Festuceae. 



