GENERA OF GRASSES OF THE UNITED STATES. 199 



Buchloe Engelm., Trans. Acad. St. Louis 1: 432. 1859. Based on Sesleria 

 dactyloides. Engelmann gave the first description of the genus. Nuttall's de- 

 scription of Seslcria dactyloides was based on the staminate plant. 



The species is usually described as dioecious * because the staminate and pis- 

 tillate flowers are found on different individuals. Experiments in growing the 

 plants from seed show that they are monoecious, the two kinds of flowers aris- 

 ing from distinct branches which propagate vegetatively, each branch produc- 

 ing its own kind. 2 Plank 3 observed that seedlings were monoecious. 



Bulbilis dactyloides (Nutt.) Raf. (Buchloe dactyloides Engelm.) 

 (fig. 118), commonly known as buffalo grass, is one of the chief 

 constituents of the sod on the Great Plains. It forms, when unmixed 

 with other grasses, a close, soft, grayish green turf. Buffalo grass 

 is dominant over large areas on the uplands, colloquially known as 

 the " short-grass country," and is one of the most important grazing 

 grasses of this region. The- sod houses of the early settlers were 

 made mostly from the sod of this grass. 



8. PHALARIDEAE, THE CANARY-GRASS TRIBE. 



99. TORKESIA Ruiz and Pav. 

 (Hierochloe R. Br., Savastana Schrank.) 



Spikelets with one terminal perfect floret and two staminate flo- 

 rets, disarticulating above the glumes, the staminate florets falling 

 attached to the fertile one; glumes equal, broad, thin and papery, 

 smooth, acute; sterile lemmas about as long as the glumes, mostly 

 somewhat appressed-hispid, sometimes awned from between two 

 lobes ; fertile lemma somewhat indurate, about as long as the others, 

 smooth or nearly so, awnless; palea 3-nerved, rounded on the back-. 



Perennial, low, erect, sweet-smelling grasses, with small panicles of 

 bronze-colored spikelets. Species about 17, confined to cool and, 

 alpine regions ; 3 species in the United States. 



Type species : Torresia utriculata Ruiz and Pav. 



Savastana Schrank, Baier. Fl. 1: 100, 337, 1789, not Savastania Scop., 1777. 

 Type, 8. hirta Schrank, the only species described. 



Torresia Ruiz and Pav., Syst. Veg. Peruv. Chil. 251. 1798. A single species 

 described. 



Hierochloe R. Br., Prodr. Fl. Nov. Holl. 208. 1810. Type, Disarrenum 

 antarcticum Labill. upon which is based the only species described (H. antarc- 

 tica). Later authors have often spelled this Hierochloa. 



Dimesia Raf., Amor. Month. Mag. 2 : 175. 1818. Based on " Holcus fra grans 

 of Pursh's Flora." This is the same as Torresia odorata. 



The common species, Torresia odorata (L.) Hitchc. (Hierochloe 

 odorata Wahl., II. borealis Koem. and Schult.) (fig. 119), called holy 

 grass, vanilla grass, or Seneca grass, grows in Canada and the north- 

 ern part of the United States. Like all the species of the genus and 

 the allied genus Anthoxanthum, it is sweet scented, owing to the 



1 Pilger discusses this and other species in a paper on monoecious and dioecious grass 

 genera. Bot. Jahrb. Engler 84 : 377. 1904. 



2 Hitchcock, Bot. Gaz. 20: 464. 1895.- 3 Bull. Torrey Club 19: 303. 1892. 



