64 ROSACEA, (rose family.) 



Petals 5, orbicular, spreading. Stamens 10 to 15, usually 2 or 3 together between the 

 petals. Fruit a membranaceous akene, included in the indurated calyx-tube. Ever- 

 green shrubs, somewhat resinous; flowers small, white, in terminal, racemose panicles. 



1. A. fasciculatum. Hook & Am, A dififusely branching shrub, 2 to 20 ft. high, 

 with reddish virgate branches and grayish shreddy bark; leaves fascicled, linear subulate, 

 2 to 4 lines long, usually channeled on one side, smooth. 



Alcliemilla arvensis. Scop., belongs here. Its minute, greenish, apetalous flowers 

 are fascicled in the axils of the small leaves and inclosed by the cleft stipules. A small 

 under herb, growing on sandy hillsides. 



Acaena trifida, R. & Pa v. Is another apetalous herb, with silky, villous leaves and 

 stem rising from a woody caudex; 3 to 15 inches high. The leaves are pinnate, the leaf- 

 lets pinnately cleft into 3 to 7 segments. The greenish flowers with purple stamens are 

 in a crowded terminal spike. Habitat similar to the last. 



11. ROSA. Toum. Rose. 



It 13 not necessary to here characterize this well-known genus. 



1. R. Californica, Cham. & Schl. Erect, 2 to 8 ft. high, sparingly armed with 

 usually recurved prickles, tomentose; leaflets 2 or 3 pairs; calyx lobes tomentose, often 

 glandular leafy; petals 6 to 9 lines long; fruit globose. 



2. R. gymnocarpa, Nutt. Slender, 1 to 4 ft. high, armed with straight slender 

 prickles or unarmed, smooth; leaflets 2 to 4 pairs, glandular; flowers solitary, rarely 2 or 

 3, rarely an inch in diameter; calyx lobes at length deciduous; fruit small, ovate or pear- 

 shaped. 



12. HETEROMELES, J. Roemer. Photinia. 



Calyx 6-parted. Petals 5, spreading. Stamens in pairs, opposite the calyx-teeth. 



Fruit red, berry -like. An evergreen shrub or small tree, with coriaceous, simple, 



sharply serrate leaves. Flowers white in terminal panicles. 



1. H. arbutifolia, Rcem. Leaves dark green above, lighter beneath, narrowly to 

 oblong lanceolate, acute at each end, 2 to 4 inches long, on short petioles, slightly revo- 

 lute margins; fruit 2 or 3 lines in diameter. 



Pirus rivularis, Dougl., the Oregon Crab-Apple, may be found in Sonoma County. 



13. AMELANCHIER, Med. Service-Berry. 



Calyx- tube campanulate; the limb 5-parted, persistent. Petals 6, oblong, ascending. 

 Stamens 20, short. Carpels 3 to 5 inferior, becoming membranaceous and partially 2- 

 celled; styles united below or distinct. Fruit berry like, globose. — Shrubs or small 

 trees; leaves simple, serrate; flowers white, racemose; fruit purplish, edible. 



1. A. alnifolia, Nutt. A shrub 3 to 8 ft. high; leaves broadly ovate, sometimes 

 cor iate at the base, serrate only toward the summit, ^ to 1^ inches long. 



