ROSACEA, (rose family.) 53 



1. C. parvifolius, Nutt. A shrub 2 to 10 ft. high, or rarely a tree, branching from 

 a thick base. Tails of the fruit often 4 inches long. 



7. PRAGARIA. Toum. Strawberry. 



Calyx persistent; limb 5-toothed, with 5 alternate bractlets. Petals white, spreading. 

 Stamens in one row. Carpels numerous, smooth; styles lateral short. Keceptacle much 

 enlarged in fruit, conical, scarlet, bearing the small akenes on its surface. 



1. F. Chilensis, Ehrh. Densely villous, with silky hairs; leaflets thick, smooth 

 above; flowers often an inch broad; fruit ovate; akenes deeply pitted. 



2. F.^ Californica, Cham. & Schl. Somewhat villous; leaves thin, veiny; fruit 

 BmaU; akenes not in pits. 



8. POTENTILLA, L. 



Calyx as in Fragaria. Petals yellow, rarely white. Stamens 20 to 50, marginal in 1 

 to 3 rows. Carpels numerous. Akenes small, on a dry receptacle. 



1. P. glandulosa, Lindl. Perennial, erect, a foot or more high; leaves pinnate; 

 leaflets 5 to 9, rounded, ovate, coarsely serrate; flowers cymose; calyx 4 to 6 lines long, 

 usually villous, with coarse hairs; bractlets shorter than the lobes; petals not exceeding 

 the calyx; stamens 25 in one row. 



2. P. Anserina, L. (Silver-weed.) White tomentose and silky-villous leaves, all 

 radical, often a foot long or more; leaflets 3 to 10 pairs, with smaller ones interposed, 

 oblong, sharply serrate, tomentose, at least beneath; flowers yellow, solitary, on scape- 

 like peduncles. 



9. HORKELIA, Cham. & Schl. 



Petals obovate to linear, often clawed, white or pink. Stamens 10, in two rows; fila- 

 ments more or less dilated; those opposite to the sepals broadest. Flowers cymose. 



* Bractlets nearly as broad as the calyx-lobes. 



1. H. Californica, Cham. & Schl. Glandular-pubescent; stems a foot high or 

 more; leaflets 5 to 10 pairs, 3 to 8 lines long; calyx about equaling the spatulate petals. 



Var. sericea, Gr. Canescent throughout, with a dense, silky pubescence; leaf- 

 lets larger. 



* * Bractlets rmich narrower than the calyx-lobes. 



2. H. tenuiloba, Gr. Canescently villous, a foot high; leaflets 8 to 12 pairs, deeply 

 incised, 2 or 3 lines long. 



3. H. Bolanderi, Gr. Densely hoary-pubescent, cespitose, the stems 3 or 4 inches 

 high, the numerous leaflets minute, with rounded lobes. 



10. ADENOSTOMA, Hook & Arn. Chamtso. 

 Calyx persistent, 5-lobed; tube obconical, 10-ribbed; lobes membranaceous, broad* 



