THE COASTAL CHAPARRAL. 191 



which range to southern Utah, western Colorado, southern New Mexico, 

 trans-Pecos Texas, and Mexico, where they blend with the Petran association. 

 The general altitudinal range of this chaparral is from sea-level to 5,000 to 

 7,000 feet, but the actual Umits vary greatly with the region and the slope. 

 The normal upper limit is rarely above 5,000 feet (plate 44). 



DOMINANTS. 

 Adenostoma FAScicxji-A'nnn. Abctostaphylus manzanita. Heteromeles arbutifoua. 



CEANOTHTTS CUNEATTJS. ARCTOSTAPHTLUS PTJNOENS. DeNDROMECUM RIOIDUM. 



ArCTOSTAPHTLUS T0MENT08A. ARCT08TAPHTT.U8 BICOLOR. ErIODICTYXJM CALIFORNICTTM. 



QxrERCTTB DUM08A. RhamntjS crocea. Adenostoma SPARSIFOUXJM. 



CeaNOTHTB DIVARICATUS. RhaMNUS CALIFORNICA. PrUNTJS lUClFOUA. 



CeaNOTHUS 80REDIATU8. RhUS raTEGRIFOLIA. PrUNTJS DEMI8SA. 



CEANOTHrS DENTATU8. RhU8 DIVERSILOBA. CercOCARPCB LEDIFOLITJS. 



Ceanothtb hir8uti:8. Rhus latjrina. Amelanchier alnifoua. 



CeaNOTHUS VERRCC08U8. RhTJ8 OVATA. HoLODI8CX;8 DISCOLOR. 



ARCTOSTAPHTLUS OLAUCA. CERCOCARPUS PARVIFOUUS. 



This Ust is in essential agreement with the more complete list of Cooper 

 (1919) for the CaUfomia chaparral. However, a number of species of Umited 

 range have been omitted. Simmondsia calif arnica is thought to belong more 

 properly to the desert scrub and the position of Adolphia calif ornica is uncer- 

 tain. Eriodictyum californicum is the typical dominant in bums and other 

 disturbed areas, but is included because of its frequence. 



More than two-thirds of the dominants Usted are confined to CaUfomia and 

 Lower California. Of the four major dominants, Ceanothus cuneatus and 

 Arctostaphylus tomentosa extend to Oregon and British Columbia, respec- 

 tively, while of those of considerable importance, ArctostaphyliLS jmngens, 

 Rhamnus californica, R. crocea, Cercocarpus parvifolius, and Amelanchier 

 alnifolia extend through Arizona into the Petran association, where the last 

 two become major dominants. 



Groupings. The number of groupings is large and only a few of the most 

 conmion can be indicated. The four major dominants frequently occur in 

 pure stands of considerable size, and this is sometimes true of other important 

 dominants as well. The general rule, however, is a mixture of several species, 

 usually 5 or more. Adenostoma is the chief dominant from Lake Coimty 

 southward in California, usually associated with several of the following: 

 Arctostaphylus tomentosa, A. glauca, Ceanothus cuneatus, Quercus dumosa, 

 Heteromeles arbuiifolia, Cercocarpus parvifolius, and Rhamnus californica^ 

 several of which may become more important locally than Adenostoma. The 

 latter drops out beyond Trinity County, and Ceanothus cuneatus and Arc- 

 tostaphylus tomentosa form the regular groupings as far as northern Oregon, 

 where the former disappears. Rhus diversiloba occurs with them frequently 

 and Cercocarpus, Amelanchier, Purshia, Holodiscus, and Philadelphus are 

 increasingly associated with them to the northward. In the San Gabriel 

 mountains of southern California, Adenostoma, Quercus dumosa, Ceanothus 

 divaricatus, Arctostaphylus, and Cercocarpus are the most important domi- 

 nants, while in the neighboring San Bernardino Range the grouping is prac- 

 tically the same, but with Cercocarpus much more important (Leiberg, 1900 : 

 419, 439). On San Jacinto Mountain, Adenostoma fasciculatum and A. sparsi- 

 folium constitute 50 to 75 per cent of the chaparral below 5,000 feet, with 



