ioo Plora of the Palouse Region 



163. AMELANCHIER. 



Shrubs or small trees, not thorny: leaves alternate, simple, 

 petioled, serrate or entire: flowers white, in racemes: ealyx-tube 

 eampanulate, 5-lobed, more or less adherent to the ovary: petals 

 5: stamens numerous, on the ealyx-tube: styles 2-5, united below 

 or distinct: ovary 5-celled, each cell 2-ovuled: berry-like pome 10- 

 celled, by the growth of a false partition in each cell of the ovary; 

 each cell i-ovuled. 



Young leaves loosely tomentose beneath, toothed only above the middle. 



A. ALNIFOLIA. 



Young leaves glabrous, bright green, mostly sharply serrate from the base: 



petals nearly 2 cm. long. A. cusickii. 



Young leaves glabrous, pallid: petals 1 cm. long. A. basalticola. 



A. alllifolia Nutt. Shrub or small tree, 2-5 m. high: leaves broadly ob- 

 long, rounded or subcordate at base, obtuse, tomentose when young, es- 

 pecially beneath, glabrate, toothed above the middle or rarely entire, 2-4 

 cm. long; petioles pubescent, 1-2 cm. long: racemes 4-8 cm. long: calyx 

 pubescent, the triangular acute lobes not longer than the tube: petals ob- 

 lanceolate, obtuse, about 1 cm. long. Common along streams and on 

 moist hillsides. 



A. CUSickii Fernald. Shrub, 3-6 m. high, with numerous virgate branch- 

 es, the young bark chestnut-brown: leaves glabrous from the first, oblong or 

 orbicular, obtuse or acute, rounded or cordate at base, mostly sharply serrate 

 the whole length; petioles slender, glabrous: racemes short, dense: cal3 T x-lobes 

 slightly hairy, acuminate, longer than the tube: petals oblong-oblanceolate, 

 obtuse, about 2 cm. long. Common on basalt ledges along Snake River and 

 Union Flat: blooming ten days earlier than the preceding. 



A. basalticola Piper, n. sp. Small shrub, with pale bark, even on the 

 young branchlets: leaves appearing before the flowers, orbicular or oblong, 

 mostly truncate at base and apex, serrate above the middle or less com- 

 monly from the base, glabrous and glaucous from the first, firm in texture, 

 1.5-2 cm. long, on slender petioles, nearly as long: racemes very short, few- 

 flowered: calyx-lobes attenuate-acuminate, sparsely hairy, longer than the 

 tube: petals narrow, oblong-oblanceolate, obtuse, 10-12 mm. long: stamens 20, 

 the filaments united into a disk-like structure at the base: styles separate: 

 mature fruit not seen. Bluffs of Snake River, Whitman county, Wash., 

 near Lewiston, Ida., Prof. Byron Hunter: no. 2988, Heller and no. 53, 

 Sandberg, McDougal and Heller, also collected near Lewiston are referable 

 here. The species is nearest A. pallida Greene. 



164. CRATAEGUS. 



Shrubs or small trees, mostly thorny: leaves alternate, petioled, 

 entire, serrate, lobed or pinnatifid: flowers white, rarely rose- 

 colored, in terminal corymbs: calyx-tube cup-shaped or eampanu- 

 late, adherent to the carpels, the limb 5-lobed: petals 5, roundish, 

 on the calyx-tube: stamens many, or only 5-10: styles 1-5, separate: 

 ovary inferior, or its summit free; ovules one to each carpel: pome 

 small, drupe-like, with 1-5 bony carpels, each 1 -seeded. 



