Oblong in outline, four to six feet high, deciduous; common on the northern slopes of hills, in clayey soil. Along the bay and Oakland hills.
Spiræa Opulifolia Linn. Nine-Bark.
Large, spreading, eight to fifteen feet high; common on the banks of creeks among the Oakland hills.
Spiraea Ariæfolia Smith.
Common on banks of creeks and northern slopes of hills, Oakland.
Cercocarpus parvifolius Nutt.
Rare, on the hills in Marin County. Its spirally-tailed seeds give the shrub an appearance as if in full blossom.
Adenostema fasciculata Hook. and Arn.
Oblong in outline, four to five feet high; very gregarious, forming extensive dense chaparral on the southern and western slopes of the Oakland bills; evergreen.