R0S1 FAMILY. 211 



persistent, its tube pitcher-shaped, i. e., enlarged above the base and some- 

 what contracted at the throat ; limb 4 or 5-parted and bearing an equal 

 number of alternate bractlets, or these minute or obsolete. Petals none. 

 Stamens 1 to 4. Pistils 1 to 4 (in ours 1), distinct, the slender style lateral 

 or arising from near the base. Achene ovate, slightly compressed, smooth, 

 concealed in the tube of the persistent calyx. (So named because valued in 

 alchemy.) 



1. A. arvensis (L.) Scop. Simple or commonly branching from the base, 



1 to 3 in. high, the branches slender and flower-bearing throughout; herbage 

 scantily pubescent with soft hairs; leaves fan-shaped, 3-parted, the segments 



2 or 3-cleft; calyx about % line long, the tube usually densely hirsute and 

 much contracted under the lobes. 



Hills and plains, common. Apr. 



12. OSMARONIA Greene. 



Shrubs with simple entire deciduous leaves and caducous stipules. Flowers 

 dioecious, white, fragrant, in nodding racemes terminating leafy branchlets. 

 Calyx turbinate-campanulate, 5-lobed, deciduous. Staminate flower with spread- 

 ing petals; stamens 15, in 3 rows, 10 inserted with the petals, 5 inserted lower 

 down upon the disk lining the calyx-tube. Pistillate flower with erect petals; 

 stamens present but abortive; pistils 5, simple, free and distinct, glabrous; 

 styles short, lateral, jointed at base; ovules 2 to each ovary, pendulous. Fruit 

 consisting of 1 to 5 ovoid drupes with a thin pulp and bony stone. Seed solitary; 

 cotyledons convolute. (Osme, Greek adjective meaning fragrant, and Aronia, 

 a genus founded by Persoon and now referred to Amelanchier.) 



1. O. cerasiformis (T. & G.) Greene. Oso Berry. Erect, 3 to 9 ft. high, 

 the branchlets reddish; leaves glabrous, broadly oblong, narrowed to each end, 

 mucronate, l 1 /* to 2y 2 in. long when mature, short-petioled; racemes with con- 

 spicuous bracts, several from leafy winter buds, rarely solitary; petals of 

 staminate flower ovate, 3 lines long; petals of pistillate flower spatulate or obo- 

 vate, 2 lines long; drupes blue-black, 5 to 7 lines long. — (Nuttallia cerasiformis 

 T. i: G.) 



Frequent in the outer Coast Kanges from the San Lucia Mts., San Fran- 

 cisco and the Oakland Hills to Humboldt Co. and northward. Rare in the 

 inner Coast Range. Marble Fork, Kaweah River, Sierra Nevada. The pulp 

 of the fruit is bitter but not poisonous. 



13. PRUNUS L. Plum. 

 Shrubs or small trees. Leaves simple, serrate. Flowers white, in corymbs 

 or in racemes from lateral buds borne on wood of the previous season, appear- 

 ing before or with the leaves. Petals 5. Calyx 5-cleft, deciduous after flower- 

 ing. Stamens 15 to 30. Pistil 1; style terminal. Drupe globose, without 

 bloom; flesh sweet or bitter; stone globose or compressed, bony. (The Latin 

 name of the Plum.) 



Leaves conduplicate in bud; drupe globose. — Cherrik.s. 



Flowers in corymbs; drupe small, bright-red 1. P. emarginata. 



Flowers in racemes; drupe dark-red. 



Peduncle leafy; drupe small, its flesh astringent; foliage deciduous. .. .2. P. demissa. 

 Peduncle leafless; drupe large, its flesh sweetish; foliage evergreen. .. .3. P. ilicifolia. 

 Leaves convolute in bud; drupe red, oblong, }£ to 1 in. long. — Plums. 



Flowers in umbels 4. P. subcordata. 



1. P. emarginata Walp. Bitter Cherry. Deciduous shrub 3 to 8 ft. high, 

 very rarely arboreous and 20 ft. high; bark smooth, dull red; leaves ovate or 



