RYDBERG: Rocky MOoUNTAIN FLORA 559 
Cotorapo: New Windsor, 1898, G. E. Osterhout 2 3 (type) ; 
also Buckhorn Creek, 1897, and Cheyenne Cajfion, 1895 ; foot- 
hills west of Fort Collins, 1893, C. & Baker. 
» Opulaster glabratus sp. nov. 
A shrub about 1 m. high; bark of the stems gray and flaky, 
that of the old branches dark brown and of the young shoots yel- 
lowish or reddish ; petioles’ 1-2 cm. long ; leaf-blades rounded- 
ovate, orbicular or sometimes slightly reniform, 2-3 cm. long, 
glabrous, slightly paler beneath, 3~-5-lobed, obtuse ; corymb 
rather small, glabrous ; bracts small, lanceolate, deciduous ; hy- 
panthium almost glabrous ; sepals oval or rounded-ovate, obtuse, 
sparingly stellate beneath, densely so above, about 3 mm. long ; 
petals rounded-ovate, about 4 mm. long, pink or white ; carpels 
2, united to above the middle, densely stellate. 
This resembles in habit a small-leaved O. intermedius, but is 
closer related to QO. monogynus, differing in the larger, less 
dissected leaves and the less stellate and larger calyx and 
hypanthium. The type grew at an altitude of between 3,000— 
3,800 m. 
CoLorapo: West Spanish Peaks, 1900, Rydberg & Vreeland 
6027 (type); Turkey Creek, 6026 ; Rist Canon, 1898 and 1899 
(collectors not given). 
“ Holodiscus microphyllus sp. nov. 
A low shrub; bark of the stems dark. brown; that of the 
branches light, yellowish or brownish, soft-strigose ; leaves spatu- 
late-cuneate, I-I.5 or rarely 2 cm. long, evenly serrate, with 
Strong nerves beneath, finely strigose or glabrate above, densely 
Soft-pubescent beneath, at first almost white, in age more glabrate ; 
inflorescence small, 3-5 cm. long, its branches short and few- 
flowered ; sepals about 1 mm. long, ovate, as well as the peduncle 
and pedicels soft-villous ; petals broadly obovate, a little exceed- 
ing the sepals; hairs of the carpels copious, about equaling the 
Stamens, 
This has gone under the name of H. dumosus, but the original 
Spiraea dumosa Nutt. is a larger plant with large inflorescence and 
larger incised or doubly toothed leaves, and apparently the same 
as S. discolor Pursh. 
_ Uran : Alta, Wahsatch Mountains, 1879, W@/. £. Jones 1142 
"(type in herb. Columbia University) ; Uintahs, 1869, S. Watson 
