Great Basin: Arizona- New Mexico District. 583 
by a scattered growth of Pinus arizonica beneath which beginning in June appear a succession 
of flowering plants. The season opens with Pentstemon Torr rreyi and ends in autumn with Gymno- 
lomia multiflora. ‘The deeper soil mountains Commelina dianthifolia, Cerastium sericeum, Achillea 
lanulosa, Cacalia decomposita, etc. On stony knolls in sunny places grow Allionia pratensis, 
Anthericum Torreyi, Calogania longifolia (of a royal purple), Phaseolus parvulus, P. Wrightii, 
Verbesina longifolia and Viguera cordifolia with great tubers of ston ny hardness, At the base or 
well-protected slopes are found Delphinium scopulorum, Vicia americana, Oenothera Hookeri and 
Solanum tuberosum boreale 
Subalpine Coniferous Forcst Formation. ı) Balsam Fir Belt: Pseudotsuga 
Douglasii is the distinctive tree of this belt (8200-9200 feet — 2 500—2800 me- 
ters) associated with Pinus flexilis var. megalocarpa, Abies subalpina and Po- 
Pulus tremuloides. The accompaning species are Actaca spicata, Berberis 
repens (= B. aquifolium), Ceanothus Fendleri, Gentiana, Geum triflorum, Ribes 
Rusbyi, Viola canadensis var. scopulorum. 
2) Spruce Belt: The characteristic trees of this belt (9200—10,5000 feet = 
2800—3200 meters) are Picea Engelmanni and Pinus aristata. 
In the ravines in this belt are Potentilla Thurberi, Mertensia paniculata, Pentstemon glaucus 
var. eis en Eaiotram Wrighti, Ligusticum scopulorum, Hieracium Fendleri, Frasera speciosa, 
Habenaria 'Thurberi, Ribes lacustre. ‘The additional prominent secondary species of this belt are 
Aquilegia an Lathyrus arizonicus, Pirola chlorantha, P. uniflora, Ribes setosum, Solidago 
multiradiata, Zygadenus elegans. 
3) Sub-Alpine or Timber-line Belt: The trees which reach timber line 
on the San Francisco Range (11,500 feet = 3500 meters) are Picea Engelmanni 
and Pinus arıstata, which exist as stunted and prostrate specimens. 
The subalpine . in the Sacramento, White, Capitan and Jicaralla Mountains is 
found between 9,000 and 11,000 feet. The principal tree is Picea Engelmanni, with subordinate 
amounts of Abies Bad Pseudotsuga, Mexican white pine, Pinus strobiformis and Po- 
pulus tremuloides generally in groves. In this narrow belt, according to Merriam!) a number 
of hardy little ae attain their maximum development, een in abundance both above and 
below. Such are: Gentiana tenella, G. barbellata, Ceras um alpinum var. Behringianum, Corallo- 
rhiza multiflora, ren alpinum, Heuchera rubescens, Pe Parryi, Draba aurea, Epilobium 
saximontanum ‚ Luz ala oe var. parviflora, Potentilla dissecta, Primula Parryi, Veronica alpina 
.W lar 
e grasse Agropyrum violaceum, Agrostis hiemalis (= A. scabra), Bromus Richardso: 
Deschampsia le Festuca ovina var. pseu oe Koeleria er Phleum alpinum, Poa 
coloradensis, P. Eatoni and Trisetum subspicatum. 
4) Alpine Formation. At the summit of San Francisco Mountain only 
lichens grow. One or two hundred feet below begins the growth of alpine 
plants. Some of these alpine plants occur on the higher peaks of the Rocky 
Mountains, the Sierra Nevada and Cascade ranges, and Mount Washington. 
In brief they inhabit the arctic regions of the globe and extend far south on 
the higher mountain ranges. 
Among these species may be mentioned Sedum rhodanthum, Luzula spadicea var. BB 
Primula Parryi, Pedicularis Parryi; Androsace ipeneinai, Alsine (Arenaria) verna, Cerastium 
1) MERRIAM, C. HART: loc. cit. 
