Part 3, 1908] ROSACEAE 265 
atomiferous between the pubescent veins beneath; inflorescence open, ovoid, 7-10 cm. long, 
5-7 cm. wide; branches few, usually ascending and simple, villous; sepals thin, ovate, 
acute, 1.5 mm. long; petals pale-pink, nearly white, oval, 1.5-2 mm. long; stamens about 
20, 2mm. long; pistils 5; carpels about 2 mm. long, their beaks over 1 mm. 
Type collected among rocks in woods along Truckee River, Placer County, California, July 17, 
1886, C. F. Sonne (herb. N. Y. Bot. Gard.). 
DISTRIBUTION : Mountains of California, Nevada, and southern Oregon, at an altitude of 
2000 m. or more. 
11. Sericotheca glabrescens (Greenman) Rydberg. 
Spiraea dumosa Torr. in Stansb. Expl. Utah 387. 1852. NotS. dumosa Nutt. 1847. 
Spiraea discolor glabrescens Greenman Erythea 7: 116. 1899. 
ffolodiscus glabrescens Heller, Muhlenbergia 1: 40. 1904. 
A diffuse shrub, 6-12 dm. high; bark of young twigs light-brown, sparingly hairy or 
glabrous, but conspicuously glandular-atomiferous, that of the older branches dull-brown 
or almost black ; leaf-blades cuneate-obovate, 1-1.5 cm. long, obtuse at the apex, decurrent 
on the short petioles, evenly toothed above the middle, glabrous or hairy on the veins, 
glandular-atomiferous and green on both sides; inflorescence more or less compound, 3-6 
cm. long; the branches short and more or less spreading; sepals ovate, acute or short- 
acuminate, 1.5 mm. long; petals white, oval, 2mm. long; stamens 20, about 2 mm. long; 
carpels 1.5 mm. long, their beaks 1 mm. long. 
TYPE LOCALITY : Stein’s Mountain, Oregon. 
DISTRIBUTION : Mountains from Oregon and northern California to Utah. 
ILLUSTRATION : Stansb. Expl. Utah Bot. p/. 4 (as Spiraea dumosa). 
12. Sericotheca fissa (Lindl.) Rydberg. 
Spiraea fissa Lindl. Bot. Reg. 26: Mise. 73. 1840; 28: Misc. 1. 1842. 
Spiraea argeniea Benth. Pl. Hartw. 82, 1841. Not S. argeniea L.. f. 1781. 
Schizonotus argenteus alpestris Kuntze, Rev. Gen, 225. 1891. 
Schizonotus argenteus fissus Kuntze, Rev. Gen. 226. 1891. 
Holodiscus argenteus bifrons Focke, Bot. Gaz. 18: 200. 1893. 
Schizonolus discolor fissus Rehder, Cycl. Am. Hort. 1627. 1902. 
A shrub, 2.5-3.5 m. high with angled branchés; bark of the young twigs gray, villous- 
tomentose; that of the older branches dark-gray or brownish; petioles 5-10 mm. long; leaf- 
blades thick, oval to lanceolate or oblanceolate, glabrous and dark-green above, white- 
tomentose beneath, 2-5 cm. long, acute at the apex, cuneate at the base and more or less 
decurrent, serrate above the middle with lance-triangular, long-mucronate teeth which are 
directed forward ; inflorescence twice to thrice compound, 5-15 cm. long, 1.5-10 cm. wide, with 
ascending tomentose branches ; sepals broadly ovate, acuminate, 2mm. long; petals rounded- 
ovate or triangular, fully 2 mm. long; petals broadly oval, 2.5 mm. long; stamens 20, about 
1.5 mm. long, inserted on a thick disk ; bodies of carpels fully 2 mm. long, slightly curved 
on the upper edge, grayish hirsute, their beaks almost as long. 
TYPE LOCALITY : Mexico. . . 
DISTRIBUTION : Mountains, from Guatemala and Costa Rica to southern Mexico. 
13. Sericotheca velutina Rydberg, sp. nov. 
A tall shrub, 1 m. or more high; bark of young twigs dark-gray and tomentose, that 
of the old stems dark-gray or purplish, almost black, exfoliating; leaf-blades oval-cuneate 
or spatulate, acute at the apex, cuneate and decurrent on the short petioles, green and finely 
velvety above, white-tomentose and villous beneath, 1.5-3 cm. long, serrate above the middle 
with lanceolate, long-mucronate teeth directed forward ; inflorescence narrow, 5-10.cm. long, 
with a few short spreading branches; sepals broadly ovate, acute, 2mm. long; petals broadly 
obovate, nearly 2.5 mm. long; stamens 20, scarcely equaling the sepals; carpels obliquely 
obovate, that is, the upper edge also curved, although less so than the lower. 
Type collected in the Sierra de San Felipe, State of Oaxaca, Mexico, Sept. 25, 1894, Charles L. 
Smith 821 (herb. N. Y. Bot. Gard.). 
DISTRIBUTION : Southern Mexico and Guatemala. 
