POLYGONACEOUS GENERA. 43 



glabrous, but the thin ocreae appressed-yillous, narrow, an inch 

 long or more and longer than the short petioles ; leaf -blades 

 elliptic-lanceolate, acute, but scarcely acuminate, 5 or 6 inches 

 long, the Tery lowest glabrous on both faces, the others rather 

 densely but finely strigulose, the midvein beneath with longer 

 stouter hairs gradually thickened from midway down to the 

 base ; very short peduncles copiously glandular-hispidulous with 

 some long bristly hairs intermixed; spikes short and stout, 

 barely 2 inches long, nearly i inch thick; bracts not strongly 

 strigose-hairy. 



Aquatic state. Floating leaves long-stalked, the blade of a 

 broad subcordate-lanceolate cut, merely acute, quite glabrous on 

 both faces, upper leaves smaller, more lanceolate, not subcordate, 

 the uppermost with traces of the pubescence of the terrestrial 

 state ; spikes long-stalked but otherwise as in the other state, 

 save that both peduncle and bracts are glabrous. 



Local, as far as known, at Mountain Lake, a small pond in 

 front of the U. S. Marine Hospital, San Francisco, where I 

 several times collected the land form from 1888 forward. I never 

 observed it as an aquatic with glabrous floating foliage ; but the 

 types of this state were obtained from the lake by my pupils 

 Michener and Bioletti, in June, 1891. 



P. HESPBEiA. Riparian, the slender stems 2 feet high from 

 prostrate rootstocks inhabiting lake-shore mud, and forming 

 dense colonies ; herbage firm, light-green, apparently glabrous, 

 the stem all the lower leaves truly so, except as to the leaf mar- 

 gins, these closely and evenly spinulose-serrulate ; petioles of 

 these 2 or 3 inches long, the broadly lanceolate merely acute 

 blades only 4 or 5 inches ; reduced uppermost leaves with a sin- 

 gle series of hair-points along all veinlets and abundant short 

 appressed thick-based very firm-pointed hairs ; short peduncles 

 glandular-hispidulous, as also the bracts of the stout cylindric 

 2-3-inch-long spikes. 



Margin of a lake near Searsville, San Mateo Co., California, 

 20 Oct., 1902, C. F. Baker, who distributes it under n. 1835. 

 An exceedingly beautiful species by the contrasted vivid green 



