54 



BOTANICAL GAZETTE [july 



The central elevation consists of the mountain ridge winch culminates 

 in the peak of Calamahuie at an elevation estimated at about 3300™. 

 To the eastward it breaks into lofty precipices and steep slopes which 

 have not been surmounted between 30 30' and 32 30' N., no passes 

 having been found in this wild stretch of ioo km . Between the main 

 range and the coast lie numerous minor ranges disposed in laby- 

 rinthine complexity, which also have not been explored. So far as 

 available information may be relied upon, no botanist had previously 

 visited this region, and some care was taken to secure living and 

 preserved specimens of the native plants whenever at all possible. 



The lower coastal slopes were found to be sandy and gravelly, the 

 depressions and near the shore furnishing suitable conditions for 

 Lyciitm Torreyi and Parosela spinosa, which latter becomes a tree 

 7 m in height. Asdepias subulafa was abundant in clumps, and 

 Ditaxis serrata grew on level areas. Other species, characteristic of 

 the lower levels, were Ibervillea tonclla, Croton calijornicum, Litpinus 

 mexicanus, and the curious Frankenia Pahncri. The low alkaline 

 pockets reached by the spring tides furnished conditions suitable for 

 Spirostachys occidentalis. Covillea, with its enormous capacity of 

 adjustment, extended from near the shore across the entire slope 

 and up the granite mountains through a range of over 6oo m in eleva- 

 tion. The various portions of the slope between the sea and the 

 first range of mountains supported ocotillo (Fouquieria splendens), 

 which attained its maximum height of io m , palo vcrde (Parkinson i a 

 microphylla), palo fierro (Olneya tesota), Bursera, and Gaertneria ilici- 

 Jolia. The streamways leading down from the mountains were inhab- 

 ited by a number of Eriogonums and euphorbiaceous herbs. A few 

 ( )puntias of the cylindrical arboreous type, an Echinocactus, a Mam- 

 millaria, and a small Cereus were also seen. Pilocereus ScJwItii, 

 which is found on the mainland far southward, here reaches the 

 greatest density yet observed, forming dense forests, acres in extent. 

 Perhaps the most notable feature from a geographical point of view 

 was shown by the presence of a great tree cactus, having the appear- 

 ance of Cereus pecten-abori^inis. Cereus Pringlei is known to be 

 abundant under the common name of "cardon" farther south, but 

 this plant appears to agree with the former, and makes a splendid 

 picture in the arid landscape, finding here its extreme northern limit 

 of known occurrence. 



