296 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 13 



this in mind the shrubby lupines of the islands will be considered here 

 as forms of Lupinus albifrons. These lupines rarely grow with other 

 plants into any semblance of an association, but rather as isolated plants 

 on rocky bluffs, or as small colonies on slopes near the sea. 



Grasslands 



Grasslands dominated by vernal soft-leaved annual grasses are 

 present on all of the islands and may be a climax formation on many 

 of the broad ridges, rolling hills, and wide terraces. Much of what is 

 now grassland, however, seems to have been shrub before the period 

 of overgrazing. This is indicated because most of the dominant grasses 

 are introductions, and because wherever grazing has been discontinued 

 for some years, as on Santa Barbara, San Clemente, and the two western 

 islands of Anacapa, shrubs and suffrutescents are beginning to re-establish 

 themselves. At present, however, the major part of the insular area is 

 grassland. The dominating grasses at the present time are Hordeum 

 murinum, Avena jatua, and Bromus mollis except for a typical bunch- 

 grass area on San Clemente, covering much of the middle section of 

 the island. This area is dominated by the indigenous perennial grass 

 Stipa pulchra, with Stipa lepida, Melica imperfecta, and Muhlenbergia 

 microsperma as sub-dominants. 



Various low species of annuals and perennials are usually inter- 

 mingled with the grasses, much as in the grassland of the mainland coast. 

 Many of these are exotics, such as Silene gallica, Medicago hispida, and 

 A triplex semibaccata. There are relatively few endemics among the 

 grasses or the annuals which are associated with them. Such annuals 

 as are endemic seem to be generally associated with coarser, more rocky 

 soils on steep slopes. The grasslands of the islands, except for those 

 on protected north slopes, all occur in fine texttured soils. This, agrees 

 with the findings of Lundegardh (1931, p. 115) who states that deep- 

 rooted plants occur in coarse soils, while shallow-rooted plants occur 

 in soil of finer texture. On the coarse soils of protected northern ex- 

 posures the evaporation rate, as shown for the northern aspect of Cave 

 Canyon on Santa Barbara, is apparently low enough to permit the 

 retention of water in the interstices of the coarser particles, sufficiently to 

 meet the needs of the shallow-rooted grasses. This grassland on sheltered 

 slopes in canyons and on sea bluffs contains such genera as Agrostis, 

 Bro?nus, Melica, and Festuca. These grasses are associated with a 

 different group of annuals and low perennials than are to be found on 

 the more exposed hills and terraces. Here again these plants are usually 



