KEY TO THE SPECIES 39 



12. CERCOCARPUS 



A rigid branching shrub, 1-3 m. high ; stamens 15-20, in 3 or 3 rows on the limb 

 of the calyx ; fruit inclosed in the persistent calyx. 



1. Cercocarpus parvifolius Nutt. (Mountain Mahogany). Leaves thiclc, 

 cuneate-obovate, serrate at apex, rather small ; somewhat silky above, tomentose 

 beneath ; flowers pediceled, the calyx-limb with short teeth ; achenes with 

 plumose tails 3-5 cm. long. Abundant on the stony slopes of hills and mountains. 



13. ROSA (Rose) 



Shrubby and usually spiny or prickly plants with odd-pinnate leaves and 

 showy flowers, an urn-shaped calyx-tube contracted at the mouth and becoming 

 fleshy in fruit, 5 broad petals inserted vdth the numerous stamens into the rim of 

 the calyx-tube which bears within and below the numerous hairy pistils, which 

 become bony achenes. 



1. Rosa Sayi Schwein. (Say's Rose). Low (less than 1 m.), branched, very 

 prickly ; leaflets 3-7 (mostly 5), elliptic, obtuse or acutisb, obscurely glandular or 

 resinous on the teeth and the under side ; sepals erect, acuminate or dilated, 

 entire or few-toothed ; flowers large, 5-8 cm. broad, usually solitary-terminal. 

 Frequent on moist wooded slopes. 



2. Rosa Woodii Lindl. (Wood's Rose). Freely branched, mostly less than 1 

 m. high ; moderately spiny ; the spines straight ; leaflets 5-9, oval, narrowed at 

 base, somewhat glaucous below; stipules glandular edged and acute ; sepals erect 

 in fruit ; flowers 3-5 cm. broad. Open grounds ; creek banks, etc. 



XXX. POMACEyE (Apple Family) 



Trees or shrubs with the characters of Rosacea, but with 

 white flowers, 2-5 styles distinct or united at base, an inferior 

 5-celled ovary, and a fleshy fruit formed by the calyx-tube and 

 ovary {pome). 



1. Amelanchier. Branches not thorny; flowers in corymbs. 



2. Cratsegrus. Branches thorny; flowers in racemes. 



1. AMELANCHIER (Seevice-bbrbt) 



Small shrubs, more rarely becoming tree-like, with 5 narrow reflcxed calyx 

 lobes, 5 narrow petals, 5 styles united below and a 5-celled ovary, becoming imper- 

 fectly 10-celled; with 1 seed in each cell. 



1. Amelanchier alnifolla Nutt. (Northwestern Sekvice-berry). Leaves 

 orbicular or oval, very obtuse, coarsely dentate above the middle, pubescent when 

 young; raceme dense, petals white, spatulate or oblong, 13-15 mm. long;, fruit 

 6-8 mm. in diameter, in ripening passing from red to purple, and finally nearly 

 black. Edible. 



2. CRAT^GUS (Thorn) 



Shrubs or usually small freely branched trees, with simple incised and serratfe 

 leaves, cup-shaped calyx, 5 rounded petals and numerous stamens, the frait with 

 5 bony seeds. 



