TWO NEW DICCIOUS GRASSES OF THE UNITED STATES. 497 
Only two genera of dicecious grasses are known to the books; of these, Spinifex, Linn., with 6 
species from the East Indies and Australia, bearing on some plants staminate and on others com- 
plete flowers, is only incompletely dicecious; the other genus is Gynerium, HBK., with five South 
American species. Some other diwcious species of genera, generally hermaphrodite, are noticed ; 
such as Calamagrostis dioica, Lour., and Guadua dioica, Steud. The unisexual grasses mostly belong 
to Oryzew, Phalaridee, Panicew, and Rottballiew ; none have been known among the tribes Stipe, 
Agrostidee, Chloride, Avenacee, Festucew, and Hordeew. They were unknown in the northern tem- 
perate zone, with the exception of Zizania and Tripsacum of North America and the cultivated 
Zea, all with heteromorphous staminate and pistillate flowers on the same plant. The dicecious 
grasses of our Flora are both species of Brizopyrum ;* Eragrostis reptans is mostly dicecious, and 
other species of this genus seem to be imperfectly so. In the following pages two new diccious 
North American grasses are described, both types of new and very distinct genera, and both, it is 
believed, belonging to Chloridee. 
BUCHLOE, Nov. Gen. 
Flores diceci, heteromorphi. 
Planta mascula ; spicules 2-3-flore, in spicis unilateralibus distiche. Glumz a uninervie ; inferior 
multo minor, Palee du, xquilonge, see excedentes ; inferior trinervis, mucro’ Het ees: binervis mutica. 
Squamule bine, truncate, emarginate. Stamina tria; anther lineares. Ovarii bee athe: nullum 
Planta foeminea : uazos ssa sae in Meas 1-3 breves capitaliformes obliquas vaginis folioram superiorum invo- 
lucratas congestze ; fl trifidam simalante Glume due ; spiculz infi- 
me amet inbetoe 1-3-nervis, apice herbaceo lanceolato-subulata seu 2-3-tida, latere inferi riore glum superioris dorso 
adnata ; glume reliquarum spicularum inferiores (quoad capitulum interne) liber, multo minores, membranacew 
etiiolonculatt: acute, uninerves ; am #e ka (externze) basi cum rhachi incrassata connate involucrum plana’ 
lantes demum lignosum, quassi osseum, ovate, enervize, pallidz, apice herbaceo nervoso trifide. Palea inferior (quoad 
capitulum interna) brevior trinervis, herbaceo-tricnspidata; palea superior brevior binervis. Squamule ut in floribus 
masculis. Staminorum rudimenta 3 minuta. Ovarium lenticulare, brevissime stipitatum glabrum ; stigmata stylis 2 
erectis se multo longiora, pilis simplicibus plumosa, ex apice floris exserta. Caryopsis libera, in capitulo 
3se um toto deciduo inclusa, sublenticularis, extus (versus paleam inferiorem), ubi embryo, plana, intus 
convexa. 
Gramen planitierum Americe Septentrionalis aridarum Missouriensium, Texensium, Mexicanarumque gregarium, 
perenne, stoloniferum, humile, sparse pilosum vel a ligulis barbatis. — Buchloé, pro nimis longo Buba- 
lochloé nomen vernaculum “ Buffalo-grass,” greece r 
BucHLOE DACTYLOIDES. 
Syn. plante mascule : Sesleria dactyloides, Nuttall, Gen. i. p. 64. Sesleria (7) dactyloides, Torrey, in Emory’s 
Rep. 1848, p. 153, Pl. X. ; id. in Whipple's Rep. Pacif. R. R. Expl. iv. p. 157. _Calanthera dactyloides, Kunth (?) in 
Hooker’s account of Geyer’s Rocky Mountain plants, in Kew Journ. Bot. viii. p. 18. Triodie spec., eee in 
Pl. Hartweg, no. 250, p. 28. Lasiostega humilis, Rupprecht (ined.) in eek FL oie Corrig. p. 347. — Drum 
mond, Tex. iii. no. 378. Lindheimer, Pl. Tex. exsicc. 569. Fendler, N. Mex. Berlandier, no. "1612 ‘nid 
1614. Hartw. 250 (fide Gray). 
. plante foeminee : Antephora azilliflora, Steudel, Glum. i. p. 111.— Drummond, Tex. ii. 359. [433] 
Wright, 1849, 785 ; 1851-52, 2079 (fide Torrey 
is remarkable plant is found in our western prairies from the British Possessions throughout the Missouri 
Se oe ce Kansas, and New Mexico, down to Texas and Northern Mexico, and is, under the name of 
‘ Buffalo-grass,’ well known to hunters and trappers as one of the most nutritions grasses, on which, for a part of the 
year, subsist and fatten the immense herds of buffalo and the cattle of the hunter and the emigrant. Since the time 
very unequally distributed in about 300 genera, many genera Missouri region and of Utah. The flowers of both sexes are 
containing only a single species, while Panicum alone com- “pages but the staminate plants are readily distinguished 
— 864, Andropogon 461, Eragrostis 247, and Festuca 239 he pistillate ones by their more slender growth, the 
mbers. ard overtopping a leaves ; while in the pistillate plants 
a Brizopyrum spicatum, Hook, is from the the latter are longer than the spikes. 
coast, and B. strictum, Torr., from the saline soils ae ‘a 
