DISTRIBUTION OF SHRUBS. I 19 



occasional clusters to the rockiest places. Next, on the 

 southern extension of the Turquoise Hills a mile east of 

 Gleeson, at about 4800 feet, it grew on any rocky exposure. 

 Crossing the Sulphur Springs Valley and the Svvisshelni 

 Mountains it was met but once near their eastern base, at 

 about 5700 feet, this time on a steep southerly aspect. 

 Reaching the southern Chiricahuas again, it was seen at 

 approximately 5000 feet to cling to rocky nooks on both 

 sides of the narrow Hunsaker Gulch, with little regard to 

 aspect. 



In the vicinity of Paradise, this shrub was again found, 

 this time in considerable numbers, on the steep and pebbly 

 banks about the head of Silver Creek. Following certain 

 indications that here promised its ascent to unusually high 

 elevations, and wishing to ascertain its aspect relations near 

 its upper altitudinal limit, it was looked for and found on 

 the top of Maxon's Peak, at 6100 feet, and on the summits 

 of the two peaks immediately north of Portal at 6350 and 

 6500 feet, respectively, in each case fully exposed to sun 

 and wind. It was common on a south slope faced with 

 great blocks of limestone 1000 feet below the higher summit. 

 Two hundred feet below the latter a ridge running east and 

 west was exami'ie' 'vith the result that it was found present 

 on the south and ajsent on the north side. On Pvlt. Desert 

 it attained to within 100 feet of the summit which lay at 

 62^0, on the south and southwest sides, but was absent from 

 all other sides. Finally, the crest of a chain of hills just 

 north of Paradise, rising toward the main axis of the range, 

 was followed, with the result that Lippia ivrighti'i w^as found 

 very sparingly two or three times, each time on rocky, exposed 

 places facing southerly, while on north or any other aspects 

 it was looked for in vain. The highest station found lay 

 on an exposed ridge sloping sharply to the south, at an eleva- 

 tion of 6600 feet above sea level. This is within 100 feet 

 of the highest point of this part of the mountains, and it 

 is barely possible that toward the main axis the species may 



