Great Basin: Arizona- New Mexico Distriet. 577 
Triodia (Trieuspis) pulchella, Bouteloua polystachya, Sporobolus eryptandrus, Koeleria .cristata, 
Sporobolus (Blepharoneuron) tricholepis, Bouteloua se Be ennata exicana, 
The in central New Mex : Agrostis rüelllahe, Agrostis 
vulgaris, Agropyrum tenerum, Eatonia obtusata, Elymus Maconil, Polypogon monspeliensis and 
Juncus balticus, — 
wet meadows of Barfoot Park in the Chiricahua Mountains of southeastern Arizona at 
8000 feet are characterized by BLUMER?) as carpeted by Trifolium pinetorum, Hypericum formosum, 
Epilobium neo-mexicanum, Mimulus cardinalis (rare), Ligusticum Porteri, Ranunculus hydrocharoides 
and the fern Athyrium oyekai m. 
The bacterial flora sL the air in the deserts of New Mexico, according to WEINZIRL, 
presents a somewhat limited number of species and this is due undoubtedly to the high winds 
which sweep uninterruptedly over wide stretches of barren country 2). 
2. The Coniferous Forest Belts and high Summits. 
Much of the forest in Arizona is on the Colorado Plateau and here it 
: reaches its best development in the vicinity of the San Francisco Moun- 
tains. From here this magnificent pine forest stretches northward to beyond 
the Grand Canyon, westward to Bill Williams Mountains, and southward 
to the rim where the Colorado Plateau breaks down to the southern plains. 
Coleogyne Association. The first 2600 feet of descent from the rim the Grand Canyon 
of the Colorado River is characterized by the presence of trees. Below this the slopes are 
treeless and the vegetation of a desert character?). 
Coleogyne ramosissima, a rosaceous shrub, extends in an almost pure growth over the 
canyon terraces at an elevation of about 3600 feet in a soil seemingly well supplied with lime. 
The absence of many desert shrubs here is presumably connected with the narrowness of the 
canyon and a rainfall greater than in the open desert. 
The Bradshaw Mountains, Mogallon Mountains, Mazatzal Mountains and the 
White Mountains may be considered southern extension of the Colorado Plateau. 
Of these mountains the Bradshaw are most poorly supplied with pine. The 
Mogollon and Mazatzal Mountains have wide strips of pine along their 
summits. The White Mountains are well timbered with Pinus strobiformis 
. ponderosa. 
The altitudinal range of species in these mountains is not rt defined, for ans reason 
that the area presents a wide diversity of climatic conditions ures. The various tree 
species prefer the north or south slopes of the canyons. For ee at the Be: of 
East Clearwater a tributary of the Little Colorado all the canyon slopes facing northward are 
timbered with Pseudotsuga Douglasii and Abies concolor (= Pseudotsuga Facies), while on 
the opposite sides of the canyon the entire forest is of Pinus ponderosa.. Only a few 
individual red firs Pseudotsuga Douglasii seem to be able to live in the face of the intense mid- 
1) BLuMER, J. C.: Muhlenbergia IV. 38o. 
2) Weinzirt, Joun: The bacterial flora of the semi-desert Region of New Eistee; with 
especial reference to the Bacteria et the Air, Journal Cineinnati Society Natural History, XIX: 
211—242. 
3) Mac Dasein: Botanical Fer of North American Deserts. Publication 99, Carnegie 
Institution 1908: 32. 
4) PLUMMER, F. 6; Rıxon, T. F., Dopwert, A.: Forest Conditions of the Black Mesa forest 
Reserve, Arizona. U. S. Geological Survey Professional Paper, 23, 1904. 
Harshberger, Survey N.-America. A 
