GRAMINE^E. (GRASS FAMILY.) 553 



$ 1. CHONDR6SIUM, Desv. Spikes pectinate, of very many spikelets, oblong 

 or linear, very dense, solitary and terminal or few in a raceme : sterile flowers 1-3 

 on the summit of a short pedicel, neutral, consisting 0/1-3 scales and awns. 



1. B. oligOStacliya, Torr. Glabrous, perennial (6' -12' high) ; leaves 

 very narrow ; spikes 1-5, the rhachis glabrous ; glumes and lower fertile palea 

 sparingly soft-hairy ; the lobes awl-pointed ; sterile flower copiously villous-tujled at 

 the summit of the naked pedicel, the 3 awns equalling the larger glume. 

 (Atheropogon, Nutt.) W. Wisconsin? and westward. Glumes obscurely 

 if at all papillose along the keel. Middle lobe of the lower palea 2-cleft at the 

 tip. Sterile flowers often 2, the second mostly a large awnless scale, becoming 

 hood-like and coriaceous. (Near B. gracilis : perhaps B. juncifolia, Laq.) 



2. B. Iiirsiita, Lagasea. Tufted from an annual? root (8' -20' high); 

 leaves flat, lance-linear, papillose-hairy or glabrous; spikes 1-4; lower glume 

 hispid with strong bristles from dark warty glands ; lower palea pubescent, 3-cleft 

 into awl-pointed lobes ; sterile flower and its pedicel glabrous, the 3 awns longer than 

 the glumes and fertile flower. (Atheropogon papillosus, Engelm. Chondrosium 

 hirtum, H. B. K.) Sandy plains, Wisconsin, Illinois, and south westward. 



$ 2. ATHEROPOGON, Muhl. Spikes short, numerous in a long and virgate 

 one-sided spike or raceme, spreading or reflexed, each of few (4-12) spikelets: 

 sterile flowers neutral, rudimentary. 



3. B. curtipendula. Culms tufted from perennial rootstalks (l-3 

 high); sheaths often hairy ; leaves narrow; spikes ^' or less in length, nearly 

 sessile, 30 to 60 in number in a loose general spike (8' -15' long) ; flowers 

 scabrous ; the lower palea of the fertile with 3 short awl-pointed teeth ; sterile 

 flower reduced to a single small awn, or mostly to 3 awns shorter than the fertile 

 flower, and 1 or 2 small or minute scales. (B. racemosa, Lagasea. Chloris 

 curtipendula, Michx. Atheropogon apludioidcs, Muhl. Eutriana curtipendula, 

 Trin.) Calcareous dry hills and plains, S. New York to Wisconsin, and south- 

 ward. July -Sept. Passes by transitions into ' . *.. 



Var. aristosa. Spikes mostly shorter ; sterile flower of a large saccate 

 lower palea, awned at the 2-cleft tip and from the lateral nerves, the stout mid- 

 dle awn often exserted, and sometimes with a rudiment of an inner palea, 

 (Eutriana affinis, .7. D. Hook.) Illinois (Geyer), Perm. ? and southward. 



19. GYUINOPOGON, Beauv. NAKED-BEARD GRASS. 



Spikelets of one perfect flower, and the rudiment of a second (consisting of 

 an awn-like pedicel mostly bearing a naked bristle), sessile and remotely alter- 

 nate on long and filiform rays or spikes, which form a crowded naked raceme. 

 Glumes lance-awl-shaped, keeled, almost equal, rather longer than the somewhat 

 equal membranaceous palese ; of which the lower is cylindrical-involute, with 

 the midrib produced from just below the 2-cleft apex into a straight and slender 

 bristle-like awn ! the upper with the abortive rudiment at its base. Stamens 3. 

 Stigmas pencil-form, purple. Leaves short and flat, thickish, l'-3' long. 

 (Name composed of yv^vos, naked, and Troo-yo)!/, a beard, iilluding to the reduc- 

 tion of the abortive flower to a bare awn.) 

 47 



