114 A. D. READ 



Sitanion pubiflorum, Gymnolomia ?nulti flora, Psoralea tenuiflora, 

 Helianthus lenticularis, Opuntia spp., Stachys sp., Tetradymia 

 canescens, and numerous species of Aster. 



TRANSITION ZONE 



For all practical purposes this zone may be considered as 

 coincident with the yellow pine (Pinus ponderosa) type of forest. 

 Having an elevation of 7000 to 8500 feet, with many springs and 

 seeps scattered through it, and a rainfall of 15 to 25 inches, none 

 of the desert plants appear. 



The predominating trees are yellow pine with some red fir 

 {Pseudotsuga taxifolia) and balsam (Abies concolor) on the 

 higher north slopes. Considerable Gambel oak (Quercus gam- 

 belii) grows under the pines while on many of the north slopes 

 there is a dense understory of locust (Robinia neo-mexicana) . 

 Scattering willows (Salix spp.) occur along the streams. Moun- 

 tain bunch grass (Festuca arizonica), pine grass (Muhlenbergia 

 gracilis), and beardless pine grass (Blepharineuron tricholepis) 

 are the most common grasses. Lupine (Lupinus hillii), and 

 species of Geranium, Potentilla, and Caslilleja are noticeable 

 weeds. One of the most poisonous of the loco weeds— rattle pod 

 (Aragallus lambertii) — is found here growing generally on north 

 slopes. Other characteristic species are Festuca arizonica, An- 

 dropogan scoparius, Bouteloua oligosiachya, Epicampes rigens, 

 Sitanion spp., Sporobolus interruptus, and S. confusus, Aristida 

 arizonica, Calochortus gunnisonii, Erythrocoma arizonica, Vicia 

 spp., Monarda stricta, Ceanothus fendleri, Sy??iphoricarpos oreo- 

 philus, Aster spp., Erigeron spp., Iris missouriensis, Senecio spp., 

 and Tithymalus montanus. 



CANADIAN ZONE 



The Canadian Zone lies on the upper slopes of Bill Williams, 

 Sitgreaves and Kendrick Mountains which are 9000 to 10,000 

 feet above sea level. Red fir (Pseudotsuga taxifolia), balsam 

 (Abies concolor), spruce (Picea engelmanni), aspen (Populus 

 tremuloides) , and white pine (Pinus flexilis) are the principal 



