132 Muhlenbergia, Volume 6 



higher elevations, and sparingly with white fir and stunted sugar 

 pine at lower altitudes. 



"Endures a variety of climatic conditions throughout range. 

 Mean annual rainfall varies from 15 to 30 inches. Snowfall 

 heavy, except in southern Rockies and southern California. 

 Growing season, from 3 to 4 months in north; somewhat longer 

 in south. Minimum temperature from about -6o° F. in north 

 to -13 F. in south; maximum temperature throughout range, 

 from 90 to 97 F. Little atmospheric moisture. 



"Appears to require full light. Never forms a dense stand, 

 and does not tend to crowd out other species; only occasionally 

 in fairly dense mixed stands. Similar in light requirements to 

 white-bark and bristlecoue pines, and less tolerant than other 

 associated conifers. 



"Moderate seeder, varying with region and elevation. Gen- 

 erally bears cones abundantly in open stands at low altitudes, 

 less abundantly in denser stands at higher elevations. Cones 

 produced locally about every year. Seeds practically wingless 

 and shed only near tree; largely eaten by birds and squirrels. 

 Mineral seed-bed most favorable for germination, which even 

 under favorable conditions is but moderate." 



Watson, Bot. King Rep. 332, says it is "the prevalent pine 

 in the East Humboldt [Ruby] Mountains, Nevada, and frequent 

 in the Wahsatch and Uintas; 6,500 to 11,000 feet altitude. The 

 aged trees of the East Humboldt Mountains, often 250 to 500 

 years old and 2 to 3 feet in diameter, rarely 50 feet high, are too 

 knotty and cross-grained to be valuable for timber." 



Coville, Cont. U. S. Nat. Herb. 4-: 221, records it from 

 southern Nevada: "This, the Rocky Mountain white pine, was 

 found on the Charleston Mountains (No. 316), growing with P. 

 aristata^ but not so abundant as that species." 



Although this pine no doubt occurs on other high ranges in 

 Nevada, I find no other recorded stations for it in the literature 

 at band. 



