114 ROSACBJE. 



c. Flowers yellow, white or purple: calyx appendaged between the lobes, or apparently un- 



equally 10-lobed. 

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



Akenea with hooked or plumose tails ................................. . ..... 12 



Akenes seed-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 S 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 petaloid: petals none ......................... ..22 



Leaves palmately lobed: greenish apetalous flowers axillary ........................ 19 



1. PBUNUS, Tournefort 



Flowert white: scraggy or spiny: leaves ovate, an inch long or less ............... 1, 8 



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 first species is a small plum, the others scarcely edible cherries.] 



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



2. P. exnarginata, Walpers. Bark chestnut brown: corymbs 6-12-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. 



6. P. Andersoni, Grl Low, diffuse: leaves oblanceolate, acute: fruit velvety. 



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



2. NTJTTAT.LIA, Gray. 



1. N. cerasifonnis, T. & G. Dioecious: 1 to 4 of the carpels maturing drapes. 



3. SPIBJBA, 



* Shrubs with rose-colored or purplish flowers: carpels 5. 

 1. S. betulaefolia: Pallas. Pale purple flowers in corymbs. Alpine, 



