132 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 13 



Northern Sonora along the coast and foothills to central Sinaloa; 

 type from Guaymas, Sonora. A small tree with irregular divaricate 

 branching, the bark brown and spotted with lenticels. The foliage is 

 sparse, especially in the arid spring when the small leaflets are reduced 

 in size and number. It is distinguished from other members of the genus 

 by its glabrous leaves, eglandular calyces, and small flowers usually not 

 more than 1 cm. long. 



Cassia confinis Greene, Pittonia 3:225. 1897. 



West cove in Concepcion Bay, March 15, Rempel 184. North end 

 of Los Angeles Bay, March 19, 20, Rempel 251. 



It has been collected only along the east side of the peninsula and 

 adjacent islands from the vicinity of Los Angeles Bay to Santa Rosalia; 

 the type from Los Angeles Bay. It is distinguished from its near Sonoran 

 relative, C. Covesii, by its larger leaves, thicker fruits, and generally 

 shorter pubescence. 



Cercidium microphyllum (Torr.) Rose& Jtn., Cont. Gray Herb. 

 II, 70:66. 1924. 



West cove in Concepcion Bay, March 15, Rempel 186, rocky hill- 

 side (sterile). 



This is one of the most common of the palo verde trees so charac- 

 teristic of the Sonoran Desert. On the mainland it reaches into southern 

 Sonora and well into middle Baja California. It forms a low spreading 

 tree with a round crown of foliage and while scatteringly common on 

 the open slopes, it attains its best development along arroyos and allu- 

 vial fans. 



Cercidium peninsulare Rose, C.N.H. 8:301. 1905. 



Agua Verde Bay, Baja California, March 10, Rempel 125 (sterile). 



Southern part of the peninsula and on Carmen and Ceralbo Islands ; 

 type from La Paz, Cape District. A small symmetrical tree with rela- 

 tively dense foliage. Goldman (C.N.H. 16:336) provided a photograph 

 of the tree and states, *'The type of this species was taken by the present 

 writer on the open plain near La Paz April 16, 1899, then in flower. 

 It is abundant throughout the Cape District south of La Paz except on 

 the upper slopes of the mountains and reaches northward to an unde- 

 termined limit, its range overlapping or so continuous with that of tor- 

 reyanum that we did not distinguish between them." 



