54 ROSACER. (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 & Arn, A diffusely 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. 
Alchemilla 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. 
Aczena trifida, R. & Pav. 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, Tourn. Rosg. 
It 1s 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 
8, rarely an inch in diameter; calyx lobes at length deciduous; fruit small, ovate or pear- 
shaped. 
12. HETEROMELES, J. Remer. PHOTINIA. 
Calyx 5-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, Rem. 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. SERVICcE-BERRY. 
Calyx-tube campanulate; the limb 5-parted, persistent. Petals 5, oblong, ascending. 
Stamens 20, short. Carpéls 3 to 5 inferior, becoming membranaceous and partially 2- 
celled; styles united below or distinct. Fruit berry like, globose.—Shrubs or small 
trees; leaves simpie, serrate; flowers white, racemose; fruit purplish, edible. 
1, A. alnifolia, Nutt. A shrub 3 to 8 ft. high; leaves broadly ovate, sometimes 
cor late at the base, serrate only toward the summit, 4 to 14 inches long. 
