SANTA CATALINA MOUNTAINS. 253 



with small, rather woolv leaves, related to our eastern milk- 

 wort (Polygala). This plant has very beautiful purple blos- 

 soms, delicately marked with yellow, which resemble legumi- 

 nous flowers, and in fact even some of the elect have been de- 

 ceived by them to the extent of placing this plant among the 

 Leguminosae. In some places another, a smaller species of Kra- 

 nicria, very similar but quite distinct, occcurs with it, giving 

 another example of two closely related species growing in the 

 same habitat. 



As the mountains are approached, the ridges, which run 

 up to the steeper slopes become more pronounced, and as wc 

 gain a somewhat higher altitude we find an even more abundant 

 vegetation in which acacias form the more important element. 

 In one spot at the foot of the mountains, somewhat to the east 

 of the mouth of Pima caiion is a grove of iron wood, palo fiero 

 (Olneya tesota) which can be recognized at a very considerable 

 distance by the dark green foliage. Close to the mountains the 

 vegetation becomes again rather more scant; and one of the 

 prominent plants in this region is a shrub, which, on account 

 of its edible fruit, we named the ''plum duff bush," but which, 

 in dignified language, is a species of Simondsia. One rather 

 easily mistakes this plant at first glance for the Manzanita, as 

 it simulates the latter in the character of its leaves and in its 

 general hal)it of growth. The hard, woody stems, however, are 

 nearly black, and the plant has, when cropped by cattle, a very 

 compact habit. Its leaves stand on edge and are glaucous, and 

 furnish a type adapted to a high degree of insolation, recalling 

 as regards position the familiar example of the prickly lettuce. 



As we approached the mouth of Pima canon we found here 

 and there a number of circles of stones, sometimes singly and 

 sometimes in twos and threes. Within each circle was a shallow- 

 pit and in this and among the stones forming the circle was usu- 

 ally to be foimd considerable charcoal. These we found later 

 to be old mescal pits made by the Pima Indians for the purpose 

 of roasting the short, thick stems of a species of agave (.4. 

 jjalmeri) or century plant and of the sotol. These mescal pits 



