102 University of California Publications in Botany. IT OL - 3 



The Arrow-weed inhabits the borders of springs, ditches, and 

 streams and frequents washes and river-bottoms, often forming 

 impenetrable thickets. The long straight stems furnish valuable 

 materials to the Indians for the making of arrows, while the 

 plants are used on the desert both by Indians and white settlers 

 for thatch in building small dwellings, sun-shades, etc. 



28. MICROPUS L. 



Slender erect floccose-woolly annuals with entire leaves and 

 clustered several-flowered heads. Involucre of a few open 

 scarious bracts surrounding the flower-bearing bracts of the re- 

 ceptacle. Receptacular bracts woolly, conduplicate, each en- 

 closing a fertile pistillate flower only the corolla-tube and style 

 of which are exserted through a lateral slit in the sac-like bract. 

 Perfect flowers in the center sterile and mostly naked. Achenes 

 gibbous, the corolla and style borne laterally, remaining enclosed 

 in the cucullate bracts which finally fall away from the recep- 

 tacle. Pappus commonly none. 



1. M. Californicus F. & M., Ind. Sem. Petrop. 1835, 42. 

 Gnaphalodes Californica Greene, Man. Bot. Reg. S. F. Bay 183 

 (1894). 



Stem erect, .5 to 2 or 3 dm. high, commonly branched only 

 toward the summit: leaves linear-oblong, acuminate: receptacle 

 low, with several scale-like processes : fruit-bearing bracts 4 to 6, 

 semiobovate, tipped with a scarious appendage, at length indu- 

 rated; the surrounding bracts of the involucre commonly 5, or- 

 bicular or ovate, scarious, with a green spot in the center : sterile 

 flowers about 3, the corolla filiform but expanding somewhat to- 

 ward the throat : 'pappus none. 



Frequent on plains and in the foothills and mountains up to 

 about 1500 m. from Southern San Diego Co. to Oregon; not 

 reported from east of the San Jacinto and San Bernardino Mts. 



29. STYLOCLINE Nutt. 



Low erect or spreading woolly annuals with small ovoid or 

 nearly globular clustered heads. Receptacle column-like or 

 almost filiform, bearing at its tip, and therefore in the center of 



