468 



RIIAMNACEAE 



broad, somewhat 3-lobed, -with obloii<; ^dands on tlic back of eacli lobe near the 

 middle. 



Dry montane slopes: Sierra Nevada from Rliasta and ]\Iodoc Cos. to Kern Co., 

 1000 to 7000 feet; hi«2:her Coast Ranp:es from Siskiyou Co. to San Luis Obispo Co., 

 1200 to 5000 feet; cismontane Southern Cali- 

 fornia, 5000 to 7000 feet. North to Wash- 

 ington. June-Aug. 



Geog. note. — The Deer Brush has its greatest de- 

 velopment in the Sierra Nevada where it is one of the 

 dominant shrubs in the lower portion of the Pinus 

 ponderosa belt (Transition zone) throughout the 

 range. A large spreading and somewhat loose shrub 

 with ample thin leaves and large showy panicles of 

 flowers, it is a distinctive feature of the forest under- 

 story, recurs in a similar zonal position in the higher 

 Coast Eanges and in a somewhat modified form in the 

 San Gabriel, San Bernardino and San Jacinto moun- 

 tains of Southern California. The Sierra Nevada 

 shrub is here taken as the biological type of the 

 species. It bears a triple-nerved ovate or ovatish leaf 

 which is rather large, that is 2 to 3% inches long. Its 

 midrib may and commonly does give off some fairly 

 marked nerves at or above the middle, but they are 

 weakly developed as compared with the basal laterals 

 which do not run out to the margin and stop, but run 

 high inside the margin. A vertical cross-section of 

 the leaf is shown in fig. 230b which by its thinness 

 and the nature of its cellular structure indicates the 

 mesophytic habitat of the shrub. 



Proceeding north through the Sierra Nevada and 

 westerly around the head of the Sacramento Valley 

 into tire-harried regions, we find that the foliage 

 often becomes somewhat reduced, sometimes with 

 many small oblong leaves on the smaller branchlets. 

 On the arid chaparral ridges of the Coast Eanges 

 from Lake Co. to the Santa Lucia Mts., ridges which have been fire-devastated for many centuries, 

 a semi-xerophytic Deer Brush is common. It is often small-leaved, sometimes with extremely 

 reduced leaves (^ to % inch long and 1 to 3 lines wide) as on Mt. Hanna in Lake Co. {Jepson 



Fig. 229. Ceanothus integerrimus 

 H. & A, a, flowering branch, X % ; 6, 

 fl., X 3 ; c, capsule, X 2. 



Fig. 230. Ceanothus integerrimus H. & A. a, mesophytic type of 

 leaf, the prevailing form in the Sierra Nevada (Colony Mill, Tulare Co., 

 Jepson 644), X V2; b, cross sect, of portion of leaf a, X 120; c, cross sect, 

 of portion of leaf d, X 120 ; d, xerophytie type of leaf (Mt. Hanna, Lake 

 Co., Jepson), X V2. 



13,985), on Mt. Konocti (Jepson 14,073), and on Loma Prieta in the Santa Cruz Mts. These 

 small leaves, associated with fire-scarred habitats, are frequently or even prevailingly oblong. The 

 vertical cross-section of the leaf reflects the sub-xerophytic habitat (fig. 230e). The oblong ones 

 are usually obscurely pinnate-veined. That is to say the adverse factors of the terrain have 

 brought about a reduction in leaf size and have inhibited triple-nerve development. But although 

 oblong leaves are so common, yet the individuals always bear a few conspicuously ovate triple- 

 nerved leaves or even a preponderance of them. Thus we seem to have a sufficiently complete 



