VEGETATION OP THE SANTA CATALINA MOUNTAINS. 21 



boulder-strewn bed is from 100 to 300 feet in width and the portions 

 covered by the storm floods vary from season to season. Trees not 

 only occupy the banks of the arroyo but occur scattered throughout 

 its bed, where they may persist for many years, only to be eventually 

 uprooted by some exceptionally severe freshet. Among these trees 

 are Populus sp., Fraxinus toumeyi, Juglans major, Platanus wrightii, 

 Sapindus drummondii, Prosopis velutina, and Sambucus mexicana, some 

 of which reach a height of 50 to 60 feet (15 to 18 m.). Such shrubs as 

 Chilopsis linearis, Baccharis sarothroides, Baccharis glutinosa, and 

 Hymenoclea monogyra are also common in and along this arroyo. 



The floor of Sabino Canon from its mouth to the Sabino Basin is 

 occupied by an irregular and broken forest of Prosopis, Populus, Frax- 

 inus, Platanus, and Salix (Salix wrightii and Salix sp.). Among these 

 common trees are scattered a few individuals of three of the oaks 

 characteristic of the Encinal region: Quercus oblongifolia, Quercus 

 arizonica, and Quercus emoryi. These oaks occur near the mouth of 

 the canon at an elevation of 2,700 feet (823 m.), although their lowest 

 occurrence on slopes, away from the proximity of an underflow, is at 

 4,200 to 4,500 feet (1,280 to 1,372 m.). Cupressus arizonica occurs in 

 the upper half of the canon and in Sabino Basin at elevations above 

 3,200 feet (975 m.). It is confined to the proximity of streams up to 

 an elevation of 6,000 feet, above which it is occasionally found on 

 slopes. 



The shrubby vegetation of the floor of Sabino Canon includes all 

 of the species which have been mentioned as occurring in the smaller 

 canons and arroyos, together with a number of shrubs and perennials 

 which are more common along the arroyos and streams of the Encinal 

 region. Among the latter are those species mentioned as occurring 

 in Soldier Canon and also Vitis arizonica, Bouvardia triphylla, Amorpha 

 californica, and Brickellia californica. 



Other characteristic plants are the shrubs Dodoncea viscosa var. 

 angustifolia, Eysenhardtia orthocarpa, Indigofera sphcerocarpa, and the 

 woody climber Nissolia schottii. 



Among the herbaceous plants common in and along the pools and 

 water-courses of Sabino Canon may be mentioned: 



Cattitriche sp. 

 Carex sp. 



Cerastium texanum. 

 Cyperus infiexus. 

 Hdenium thurberi. 

 Hydrocotyle ranunculoides. 

 Isnardia palustris. 

 Juncus arizonicus. 

 Juncus bufoniw. 

 Juncus interior. 

 Juncus spharocarpus. 

 Linaria canadcnsis. 

 Mecardonia peduncularis. 



Mimulus langsdorfii. 

 Mimitanthe pilosa. 

 Montia perfoliata. 

 Myosurus cupulatus. 

 Phalaris intermedia. 

 Platystemon californicus. 

 Polygonum sp. 

 Senedo lemmmi. 

 Specularia biflora. 

 Stachys coccinea. 

 Stemodia durantifolia. 

 Tagetes lemmoni. 

 Tillcea erecta. 



