ROSACEiE, • 49 



c. Flowers yelhto, white or jjwrple: calyx appendaged betioeen the hhes, or apparently un- 



equally 10-lobed. 

 Stamens 20 or more: carpels very numerous: receptacle conical to clavate 



Akenes with hookerl or plumose tails 12 



Akenes seeil-like on a juicy receptacle: leaves 3-foliolate 13 



Akenes seed-like on a dry receptacle. (Try No. 16 and 17.) 14 



Stamens 20 or less: carpels few or many on a dry receptacle. 



Stamens 10 (or 20 and corolla pink): corolla white: receptacle nearly naked 16 



Stamens 5 to 20; filaments slender: carpels few or 1 : receptacle hairy 17 



Stamens .5: carpels 5 to 10: leaflets 3, cuneate, 3-5-toothed 15 



d. Flowers small: carpels 1 to 3 becoming akenes enclosed by the firm, calyx-tube forming a 



apparently inferior ovary. 



Leaves pinnate flowers in heads or spikes. 



Calyx with barbed prickles: petals none: anthers purple 21 



Calyx with a margin of hooked prickles: petals yellow 20 



Calyx 4-angled, naked, limb petuloid: petals none 22 



Leaves palmatelj' lobed: greenish apctaloiis flowers axillary 19 



1. PRUNUS, Tournefort. 



Flowers white: scraggy or spiny: leaves ovate, an inch long or less 1, 3 



branches slender: leaves 1 to 4 inches long 2, 4 



low: leaves spatulate, entire, 6 lines long, sessile 7 



evergreen leaves, shining, prickly toothed, broad 5 



Flowers rose-color: low, spiny: leaves oblanceolate, 6 to 12 lines long 6 



[The fir.st species is a small plum, the others scarcely edible cherries.] 



1. P. subcordata, Benth. Bark ashy gray: flowers in small lateral clusters. 



2. P. emarginata, Walpers. Bark chestnut brown: corymbs 6 r2-flowered. 

 Var. mollis, Brewer. Taller, becoming 25 ft. high, woolly. Oregon. 



3. P. Fremonti, Walp. Flowers solitary or few together: ovary densely hairy. 



4. P. demissa, Walp. Dense racemes 3-4 inches long, erect: leaves large. 



•5. P. ilicifolia, Walp. Racemes small, axillary: fruit ripening in November. 

 G. P. Andersoni, Gr. Low, dififuse: leaves oblanceolate, acute: fruit velvety. 

 7. P. fasciculata, Gr. Similar: slender petals recurved: stamens 10-15: 



2. NUTTALLIA, Gray. 

 1. N. cerasiformis, T. & G. Dioecious: 1 to 4 of the carpels maturing drupes. 



3. SPIRJEA, Linnaeus. 

 * .'^hiiibs with rose-colored or purplkh /lowers: carpels 5. 

 1. S. betuleefolia: Pallas. Pale purple flowers in corymbs. Alpine. 

 9 



