WOOTON AND STANDLEY—FLORA OF NEW MEXICO, 119 
Pistillate spikes erect or, if drooping, the perigynia 
differing from above. 
Achenes normally lenticular and the stigmas 2. 
Perigynia golden yellow at maturity; spikes 
few-flowered; plants low, slender. (Br- 
COLORES.).......2.222-02 20202202 e eee eeeee 28. 
Perigynia not golden yellow at maturity; 
spikes many-flowered; plants tall or 
stout. (RIGIDAE.) 
Perigynium beak strongly bidentate; peri- 
gynia ribbed...............-...22---- 33. 
Perigynium beak, if present, not bidentate; 
perigynia various. 
Lowest bract not exceeding the inflores- 
Lowest bract exceeding the inflores- 
cence. 
Perigynia pale green, finely many- 
merved...... 2 cece eee eee eee eee 30. 
Perigynia greenish straw-colored, few- 
nerved or nerveless. 
Leaf blades flat and canaliculate, the 
edges serrulate above only; peri- 
gynia at most obscurely nerved. .31. 
Leaf blades, at least the lower, pli- 
cate, the margins revolute, the 
edges serrulate troughout; F peri- 
gynia few-nerved...............32. 
Achenes triangular; stigmas 3. 
Perigynia beakless or very shortly beaked. 
Terminal 2 or 3 spikes staminate. (TRa- 
CHYCHLAENAE.) .....-.-+-0-+--+----- 37. 
Terminal spikes pistillate above, stami- 
nate below. (ATRATAE.) 
Perigynia 2.6 mm. long or less, little 
compressed, the margins not ap- 
pearing winglike..................34. 
Perigynia more than 2.5 mm. long, 
strongly compressed, the margins 
winglike. 
Spikes all closely sessile, contiguous, 
forming a dense lobed head-..... 35. 
Lateral spikes peduncled, distant, 
usually nodding.............-.-- 36. 
Perigynia strongly beaked, the beak deeply 
bidentate 
Perigynia or sheaths pubescent. (Hir- 
TAE.) 
Perigynia pubescent, the teeth short; 
sheaths glabrous..........-.-- 38. 
Perigynia glabrous, the teeth long; 
sheaths pubescent......-.-.-. 39. 
C. aurea. 
C. nebrasken- 
sis. 
. C. scopulorum, 
C. kelloggii. 
C. variabilis. 
C. emoryi. 
C. ultra. 
C. halleri. 
C. nova. 
C. bella. 
C. lanuginosa. 
C. atherodes. 
