Chamaebatiaria millefolium (Torr.) Maxim.

Chamaebatiaria millefolium (Torr.) Maxim. Acta Hort
Petrop. 6: 225. 1879.
Spiraea Millefolium Torr. Pacif. R. R. Rep. 4 : 83. 1857. Sorbaria Millefolium Focke, in E^. & P. Nat. Pfl. 3^ : 16. 1888. Basilima Millefolium Greene, Fl. Fran. 57. 1891.
A densely branched shrub, less than 1 m. high ; bark of the young twigs brown, more or less densely covered by a stellate tomentum ; that of the old stems glabrous and gray ; leaves 2-4 cm. long, more or less crowded at the ends of the branches, glabrous above, stellate-tomentose beneath, short-petioled, oblong in outline ; primary divisions, of about 20 pairs, 4-8 mm. long, the upper confluent; secondary divisions 15-17 pairs, subalternate, decurrent, about 0.5 mm. long, entire, obovate ; panicle 3-10 cm. long, leafy below ; sepals lanceolate-deltoid, acute, 3 mm. long ; petals white, rounded-obovate, about 5 mm. long, wavy and crenulate ; stamens of about the same length ; follicles about 5 mm. long, lanceolate, glabrous; seeds linear-lanceolate.
Type locality : Low hills and valleys near William's Mountains [Arizona]. Distribution : Among rocks, from Idaho and Nevada to Arizona and southern California.

Chamaebatiaria glutinosa Rydberg, sp. nov
A shrub, 1-2 m. high; bark of the young twigs brown, somewhat stellate and very glutinous; that of the old stems grayish-brown and glabrous; leaves 4-5 cm. long, glabrous above, somewhat stellatevillous beneath ; primary divisions 15-20 pairs, 6-10 mm. long, the upper confluent ; secondary divisions 6-10 pairs, 1-2 mm. long, obovate, usually more or less toothed ; panicle 4-5 cm. long, leafy ; sepals lanceolate, 3 mm. long, acute ; petals rounded-obovate, 4.5-5 mm. long, crenulate ; fruit unknown.
Type collected in a precipitous canon on the western slope of Mammoth Range, a few miles from Ellsworth, Nye County, Nevada, in 1868, M. B, Howard (herb. Columbia Univ.). Distribution : Type locality and neighboring California.