46 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 13 



concluded that they are coincident with the elevations and tracks of 

 regular fog ingressions. 



A local Chaparral, dominated by Arctostaphylos, Adenosiema, Quer- 

 cus, Eriogonurn, and Juniperus, occurs on the northern slopes of the 

 highest peaks, above the pine forest. This is a most interesting ecologic 

 find with considerable historical significance. Small patches of Coastal 

 Sagebrush and Juniper Woodland border the pine stands irregularly. 



These formations show little or no natural transitional grading, but 

 are sharply one or the other. Where the pine forest begins, the desert 

 shrub leaves off. Chaparral occupies higher elevations than the pines and 

 both formations appear largely dependent upon the upsurging fogs from 

 the westward, especially the latter. These are aspects peculiar to the 

 island, and while the vegetations show climatic qualities, they are inter- 

 esting instances of what climate and soil t3'pes have generated out of the 

 limited plant materials available. 



The flora of the island is now known to consist of about 182 species 

 of vascular plants and has recently been annotated by Eastwood (1929) 

 and Howell (1942). Around 600 numbers have been taken by 14 col- 

 lectors, but little collecting has been done in summer, only one small 

 one made in winter (Pond, 15 numbers), and none at all during the 

 fall (Table 2). Considering this, the fact that little or no collecting 

 has yet been done on the western side, the areal nature of the island, 

 and the irregular rainfall, I would estimate that some, perhaps 10%, 

 of the island flora is still unreported. In addition to the unknowns, more 

 material of many of the known plants, and more field work are needed 

 for a thorough evaluation of the Cedros flora. 



The plant collections of the Allan Hancock Expeditions to Cedros 

 Island were made in 1937 by P. J. Rempel and in 1939 by Francis H. 

 Elmore. They are enumerated belov/ together with Rempel's collection 

 from the neighboring San Benito Islands. Their collections add three 

 genera and four species to the Cedros Island flora: Aristida adscensionis, 

 Eschscholtzia minutiflora, Fagonia laevis, and Euphorbia bartolomaei. 



