ILLUSTRATIONS. 



XIII 



Plate 35 — Continued. 



B. Artemisia californica, Salvia melli- 



fera and Eriogonum fasciculatum 

 sasociation, Elsinore, California. 160 



C. Coastal sagebrush with Adenostoma 



in ravines, Temecula, California. 160 

 Plate 36. 



A. Larrea consociation, Stockton, 



Texas 168 



B. Larrea-Flourensia association, Pecos, 



Texas 168 



C. Larrea plain, Sierra Blanca, Texas. 168 

 late 37. 



A. Larrea consociation, Tucson, Ari- 



zona 170 



B. Prosopis consociation, San Pedro 



Valley, Arizona 170 



C. Parkinsonia torreyana and Acacia 



greggii, Tucson, Arizonia 170 



Plate 38. 



A. Larrea and Franseria dumosa, Ajo, 



Arizona 172 



B. Larrea, Prosopis and Hilaria rigida, 



Ajo, Arizona 172 



C. Encelia farinosa on lava ridge, Ajo, 



Arizona 172 



Plate 39. 



A. Cereus-Encelia on lava ridge with 



Larrea below, Tucson, Arizona. 174 



B. Parkinsonia microphylla and Cereus 



giganteus on foothills of Tucson 

 mountains 174 



C. Fouquiera splendens consociation, 



Santa Rita Reserve 174 



Plate 40. 



A. Fouquiera subclimax in Larrea plain, 



Tucson, Arizona 176 



B. Opuntia fulgida consociation, San 



Pedro Valley, Arizona 176 



C. Opuntia discata, fulgida and spino- 



sior, Tucson, Arizona 176 



Plate 41. 



A. Quercus-Rhus-Cercocarpus associa- 



tion, Manitou, Colorado 182 



B. Detail of same, Quercus and Rhus in 



foreground, Cercocarpus behind, 

 Manitou, Colorado 182 



C. Cercocarpus parvifolius consociation, 



Chugwater, Wyoming. 182 



Plate 42. 



A. Quercus-Cercocarpus-Fallugia chap- 



arral, Milford, Utah 184 



B. Same showing contact with sage- 



brush, Cercocarpus ledifolius in 



foreground, Milford, Utah.. 184 



Plate 43. 



A. Rhus glabra consocies, Peru, Nebras- 



ka 188 



B. Quercus virens and undulata, Ed- 



wards Plateau, Sonora, Texas.. 188 

 Plate 44. 



A. Chaparral hills and sagebrush val- 



ley, Pine Valley, California 190 



B. Adenostoma-Ceanothus association, 



Descanso, California 190 



Plate 45. 



A. Pinus-Juniperus association, Grand 



Canyon, Arizona igg 



PAGE. 



Plate 45 — Continued. 



B. Detail of pinon-cedar woodland, 



Delta, Colorado 198 



Plate 46. 



A. Quercus-Juniperus association, Santa 



Rita mountains, Arizona 200 



B. Quercus arizonica consociation, Santa 



Rita mountains 200 



Plate 47. 



A. Pinus-Quercus association, Chico, 



California 202 



B. Quercus douglasii consociation, Red 



Bluff, California 202 



Plate 48. 



A. Pinus ponderosa consociation, Flag- 



staff, Arizona 206 



B. Pinus ponderosa consociation, Bend, 



Oregon 206 



C. Pinus ponderosa consociation, Black 



Hills, South Dakota 206 



Plate 49. 



A. Pseudotsuga mucronata consocia- 



tion, Alpine Laboratory, Pike's 

 Peak 210 



B. Detail of Pseudotsuga- Abies forest, 



Cameron's Cone, Pike's Peak . . 210 

 Plate 50. 



A. Pinus ponderosa-lambertiana asso- 



ciation, Prospect, Oregon 212 



B. Pinus, Libocedrus, Abies, and Pseu- 



dotsuga, Yosemite National Park, 



California 212 



Plate 51. 



A. Pseudotsuga, Thuja, and Tsuga, Rai- 



nier National Park, Washington. 216 



B. Sequoia sempervirens consociation, 



Muir Woods, Mount Tamalpais, 



California 216 



Plate 52. 



A. Pseudotsuga, Tsuga, and Pinus mon- 



ticola, Carson, Washington 220 



B. Pseudotsuga, Pinus monticola, Larix, 



and Thuja, Priest River, Idaho.. 220 

 Plate 53. 



A. Picea-Abies association at Monarch 



Pass, Salida, Colorado 224 



B. Picea-Abies association on Uncom- 



pahgre Plateau, Colorado 224 



C. Picea-Pinus aristata at timber-line, 



King's Cone, Pike's Peak 224 



Plate 54. 



A. Tsuga lyallii consociation, Crater 



Lake, Oregon 226 



B. Abies magnifica consociation, Glacier 



Point, Yosemite National Park, 



California 226 



Plate 55. 



A. Carex-Poa association, King's Cone, 



Pike's Peak 228 



B. Carex consociation, Campanula so- 



ciety, Pike's Peak 228 



Plate 56. 



A. Polygonum bistorta society, Pike's 



Peak 232 



B. Campanula rotundifolia society, 



Pike's Peak 232 



C. Mertensia alpina society, Pike's 



Peak 232 



