276 rosackjE. 



Herbs. 

 Perennials. 

 Pistils many on a convex receptacle, becoming achenes; calyx with a 

 row of bractlets alternating witli the sepals. 

 Keceptacle fleshy; leaves 3-toliolate .... 7. Fragaria. 



Receptacle dry; leaves digitate or pinnate ... 8. Potentilla. 



Pistil 1; leaves pinnate. 

 Petals yellow; jirickles of calyx hooked at tip . . 9. Agrimonia. 

 Petals none ; prickles of calyx straight, but retrorsely barbed . . . 



10. ACjENa. 

 Annuals; diminutive plants, with palmately divided leaves; petals 

 none; pistil (in ours) 1, becoming an achene .... 11. Alchemilla. 

 Trees or shrubs with simple leaves and early-falling stipules; fruit a drupe. 

 — DRT3PE2E (Cherry Tribe). 

 Flowers dicecious; pistils 5; drupes 1 to 4 . . ... 12. Osmaronia. 



Flowers perfect; drupe solitary. 

 Leaves conduplicate in the bud ; drupe without bloom ; stone spherical. 



13. CERAStlS. 



Leaves convolute in the bud; drupe with bloom ; stone compressed . . 



14. Prunus. 

 B. Ovary inferior. 



Trees and shrubs with simple leaves and free stipules; •fruit a pome, con- 

 sisting of a 2 to 5-celled ovary which is enclosed In and mostly adherent 

 to the fleshy calyx-tube. — Pome^ (Apple Tribe). 

 Leaves evergreen, coriaceous; flowers small, numerous in a corymbose 

 panicle; fruit bright red, the 2 carpels enclosed in the berry-like 



calyx . . . , . 16. Heteeomeles. 



Leaves deciduous. 

 Flowers in corymbs ; ovary 2 to 5-celled. 

 Pome drupe-like, containing 2 to 5 bony stones, either separable or 



united into one; branches bearing thorns .... 16. Crat^egus. 

 Pome containing 2 to 5 papery or cartilaginous carpels, each 2-seeded . 



17. Maltjs. 

 Flowers in racemes, showy; ovary 6-celled, each cell in fruit becoming 

 2-celled by a partition from the back . . . 18. Amelanchier. 



1. OPULASTER Medic. Nine Bakk. 

 Diffuse shrubs with reddish brown shreddy bark. Leaves simple; 

 stipules deciduous. Plowers white, in corymbs terminating lateral 

 leafy branchlets. Calyx campanulate, 5-cleft, persistent. Petals 5, 

 rounded, equal. Stamens 20 to 24. Pistils 1 to 5, mostly 3, some- 

 what united toward the base, becoming as many inflated 2 to 4-see,ded 

 follicles dehiscent along both sutures. Seeds crustaceous, shining, 

 with copious endosperm.— (Opulus, ancient Latin name of a kind of 

 maple tree, and aster, a sumx meaning wild.) 



1. O. opulifolius (L.) Kuntze var. capitatus. Three to 5 ft. 

 high or often with sucker-like stems nearly twice as long, commonly 

 forming with other shrubs and with climbers a dense tangle; leaves 

 roundish or ovate, 3-lobed and irregularly serrate, glabrous or 

 scabrous above, stellate-pubescent beneath, 1 to 2 in. long, on peti- 

 oles J in. long or more; leaves of sterile .shoots similar but larger; 

 pedicels and calyx pubescent; corymbs hemispherical, f to 1 in.' 

 high; petals IJ lines long; stamens alternately long and short; pods 

 divergent, commonly 3 to 4 lines long, splitting into 2 valves.— 

 (Neillia oapitata Greene.) 



Common along streams in the hills, often- gregarious on steep north 

 hillsides: Oakland Hills; Marin Co.; Napa Valley and northward; 

 apparently not occurring in the inner North Coast or Mt. Diablo 



