ROSACEAE. 211 



Very common in open places. F. cuneifolia Nutt. is probably indistin- 

 guishable. It is usually characterized by having narrower more cuneate 

 longer-stalked thinner less-reticulated leaflets and slightly smaller flowers; 

 but all of these characters are decidedly variable in F. chiloensis. 



Fragaria crinita Rydb. Very similar to F. chiloensis but more hairy, not 

 reticulated, some of the pubescence loose and spreading; petioles densely 

 hirsute. 



Infrequent, British Columbia to California. 



Fragaria bracteata Heller. Rootstocks stout; scapes 10-20 cm. high, 

 usually exceeding the leaves; whole plant sparsely silky -villous; leaflets 

 broadly obovate, cuneate at base, coarsely dentate; lateral leaflets oblique; 

 flowers 1.5-2 cm. broad; petals nearly orbicular, somewhat longer than the 

 spreading sepals; fruit oblong, the akenes on the surface. 



In prairies and open woods, common. 



Fragaria helleri Holzinger. Very similar to F. bracteata; petals pink; 

 flowers more often nodding. 



Known from only a few localities, namely Olympia, Olga, and Woodlawn, 

 Washington, and Latah County, Idaho. Probably not distinct from F. 

 bracteata. 



284. COM ARUM. 



Stout dark green nearly glabrous perennial herbs; leaves alter- 

 nate, pinnate, with large stipules; flowers large, cymose or soli- 

 tary, terminal or also axillary; calyx deeply 5-lobed and with 5 

 narrow bractlets; petals shorter than the calyx-lobes, acute, 

 purple; stamens numerous on the large pubescent disk; pistils 

 numerous on the pubescent receptacle which becomes spongy in 

 fruit; styles lateral; akenes glabrous. 



Comarum palustre L. Perennial; stems decumbent, rooting below, 30-90 

 cm. long; leaves pinnately 5-7-foliolate; leaflets elliptic or oblong, serrate, 

 obtuse, more or less pubescent beneath, 5-8 cm. long; cyme few-flowered; 

 flowers dark-purple. 



In swampy places or shallow water especially along lake shores, common. 



285. ARGENTINA. 



Stoloniferous creeping herbs with pinnately compound leaves; 

 flowers axillary solitary; calyx deeply 5-lobed and with 5 alternate 

 bractlets; petals yellow; stamens 20 or more; carpels numerous 

 on a small villous receptacle ; style filiform, lateral ; akenes glabrous. 



Argentina grandis (T. & G.) Piper n. comb. (Potentilla anserina grandis 

 T. & G.; P. pacifica Howell; Argentina occidentalis Rydb.) Leaves 30-40 cm. 

 long, with 7-31 principal leaflets, bright green above, white tomentose be- 

 neath; leaflets oblong to obovate, coarsely serrate, the larger 4-6 cm. long; 

 peduncles 10-30 cm. long, nearly glabrous; akenes firm, laterally compressed, 

 rounded on the back. 



Abundant along the seashore, rare elsewhere. 



286. DRYMOCALLIS. 



Very similar to Potentilla; leaves pinnate; flowers yellow or 

 whitish; stamens in groups on a thick fleshy disk; anthers flat; 

 styles lateral, nearly basal; seeds ascending, orthotropous. 



