258 PATAGONIAN EXPEDITIONS I BOTANY. 



a2. Culm triangular-filiform. Umbel 2-3-rayed. Bracts 2. Achenes blackish. Scales yel- 

 lowish, flavits. 



#3. Culm compressed. Head lax, 2-bracted. Achenes biconvex. Awn straight, quadrangular. 



cimicinus. 



I. C. ARISTATUS Rottb. 



Root fibrous, slender, cespitiferous. Culms triquetrous, erect, 14 cm., 

 glabrous. Leaves linear, carinate, as long as the culm. Umbels 1-5- 

 ' radiate; rays unequal, polystachyous ; spikelets fasciculate-capitate, 8-15- 

 flowered ; heads oblong or elliptic-globose. Invohicre 3-4-leaved, very 

 long; leaves y-g-nerved, acuminate, awned, the awns uncinate, yellow- 

 green ; achene oblong, triangular, apicate, fuscescent, finely punctulate, 

 one third as long as the scale. 



(Orient, Africa, Chili); N. Patagon., in Isla de Crespo, Rio Negro. 



2. C. CIMICINUS Presl. (C. lorentziamts Bcklr.) 



Rhizome small, fibrous. Culms i-few, 15 cm. high, compressed, few- 

 leaved. Leaves shorter than culm, complicate, spinulose-toothed. Head 

 solitary, lax, with 2-leaved involucre. Spikelets 5-16, diverging, moder- 

 ately compressed, linear-oblong ; scales with lucid castaneous sides ; fruit 

 minute, scarcely half as long as the scale, compressed-biconvex, obovate, 

 umbo-articulate, reticulate ; rachilla straight, quadrangular. 



(Argentina); N. Patagon., in wet parts along Rio Negro, near Carmen. 



3. C. FLAVUS Presl. 



Roots fibrous, cespitiferous. C^tlms triangular-filiform, 30 cm. high, 

 leafy at base. Leaves very narrow, half as long as the culm. Invohicral 

 leaves 2, filiform, divaricate, exceeding the simple, 2-3-rayed umbel, with 

 2-3 spikes, having i4-i8-flowered linear-lanceolate, divaricate spikelets. 

 Scales ovate-obtuse, 3-nerved, yellowish. Achene obovate, subglobose, 

 punctulate, blackish. 



(Mexico; Brazil; Argent); Patagon. 



4. C. MELANOSTACHYUS VARIEGATUS Knth. 



Style bifid. Root fibrous. Culms cespitose, ascending, 10 cm., triqiiet- 

 rous, leafy at base. Leaves plane, linear, glabrous, shorter than the culm. 

 Umbel 5-8-rayed, dense with very short rays ; umbellules 4-6-stachyous ; 

 involucre about 4-leaved, much exceeding the umbel. Spikelets ovate- 



