VEGETATION OF 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 wrightit, 
Sapindus drummondit, 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 Cafion from its mouth to the Sabino Basin is 
occupied by an irregular and broken forest of Prosopis, Populus, Frax- 
mus, Platanus, and Salix (Saliz wrighttt 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 cafion 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 cafion 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 Cafion includes all 
of the species which have been mentioned as occurring in the smaller 
cafions 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 Cafion and also Vitis arizonica, Bouvardia triphylla, Amorpha 
californica, and Brickellia californica. 
Other characteristic plants are the shrubs Dodonea viscosa var. 
angustifolia, Eysenhardtia orthocarpa, Indigofera spherocarpa, and the 
woody climber Nissolia schottit. 
Among the herbaceous plants common in and along the pools and 
water-courses of Sabino Cafion may be mentioned: 
Callitriche sp. Mimulus langsdorfii. 
Carex sp. Mimitanthe pilosa. 
Cerastium texanum. Montia perfoliata. 
Cyperus inflecus. Myosurus cupulatus. 
Helenium thurberi. Phalaris intermedia. 
Hydrocotyle ranunculoides. Platystemon californicus. 
Isnardia palustris. Polygonum sp. 
Juncus arizonicus. Senecio lemmoni. 
Juncus bufonius. Specularia biflora. 
Juncus interior. Stachys coccinea. 
Juncus spherocarpus. Stemodia durantifolia. 
Linaria canadensis. Tagetes lemmoni. 
Mecardonia peduncularis. Tillea erecta. 
