100 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 13 



being I. M. Johnston, who frequently made more than one collection 

 of a species at one locality or on one island. The list of collectors is not 

 complete, but as far as I have been able to determine from literature, 

 it includes all of the important ones. Others that may have collected on 

 the islands, as Diguet and George Lindsay who had special interests in 

 the Cactaceae, have provided few, if any, cited records. 



From the table it is clear that botanical exploration has been fleet- 

 ing. On all except San Pedro Martir and Carmen Islands the summer 

 flora has not been collected and is therefore imperfectly known. While 

 many of the xerophytes produce leaf and bloom following both winter 

 and summer rains, there are also many which respond only in the sum- 

 mer-fall period. These latter are abundant in the southern portion of 

 the region, where summer rains are heavier. Except for Johnston's pub- 

 lished notes of a general nature, the ecology of the islands has been given 

 only the most cursory attention. The development of the vegetation, the 

 nature of plant communities, the amount of endemism, and the many 

 diverse problems facing the phytogeographer cannot be determined until 

 further careful and less nomadic field work has been systematically done. 

 In Table 7 are listed all the plants that have been recorded from the 

 larger California gulf islands. A few of the smaller islands have been 

 omitted from the table for reasons of space, smallness of flora, or because 

 their floras are unknown. 



Among the numerous small islands, the floras of which have not been 

 collected, are Consag Rock, Smith, Tassne, and Montague Islands. The 

 known plants on Mejia and Granite Islands are included in the list of 

 Angel de la Guardia Island. Omitted are some small islands found in 

 the bays of Guaymas, Concepcion, and La Paz (Pichilinque). Islands 

 having small lists of spring flora are the following: 

 Georges Island 



Chenopodium murale L. 

 Patos Island* 



Bouteloua barbata Lag. Atriplex Barclayana typica H. & 



C. 



Amaranthus fimbriatus (Torr.) Atriplex Barclayana Palmeri 

 Benth. (Wats.) H. & C. 



Carnegiea gigantea (Engelm.) Machaereocereus gummosus (En- 



Britt. & Rose gelm.) Brit. & Rose 



Opuntia sp. Encelia farinosa phenicodonta 



(Blake) Jtn. 



* In 1945 all the sporophytes were stripped off Patos Island by a Mexican guano 

 company and the guano producing Peruvian cormorant was introduced. 



