NATIVE WOODY PLANTS OF THE UNITED STATES 195 
Platanus occidentalis L. Sycamore. 
Range: 16, 20, 21, 22, 24, 25, 26, 27, 28, 29, 30. 
Site: Moist, well-drained, sun. 
Fruit: Achene; available in October, persistent through the winter. 
A very large, spreading tree; root system shallow, wide spreading; rapid 
growing, long-lived; much decayed with age; grows on coal-stripped lands 
in Illinois; wood of importance commercially ; 100,000-170,000 seeds per pound, 
germination 5-10 percent, slow. 
Stomach records: Mallard. Observations: Four species of birds; white- 
tailed deer; somewhat eaten by muskrat. 
Platanus raceinosa Nutt. California sycamore. 
Range: 8, 4, 5. 
Site: Well-drained, moist, sun. 
Fruit: Achene. 
A large tree; somewhat tolerant of alkali; trunk commonly leaning, hori- 
zontal, or even prostrate; wood not durable. 
Observations: Goldfinch; California mule deer. 
Platanus wrightii Wats. Arizona sycamore. 
Range: 10, 11. 
Site: Well-drained, moist, sun. 
Fruit: Achene. 
A large tree. 
Pluchea borealis, see Pluchea sericea. 
Pluchea sericea (Nutt.) Cov. Arrowwood. 
Polypappus sericeus Nutt., Tessaria borealis DC., Pluchea borealis Gyray., 
Berthelotia sericea Rydb. 
Range: 9, 10, 11. 
Site: Well-drained, moist, sun. 
Fruit: Achene. 
A large, willowlike shrub; flowers November-—June; often forms dense, pure 
stands. 
Observations: California mule deer. Somewhat nibbled by cattle and horses. 
Poliomintha incana (Torr.) Gray. 
Hedeoma incana Torr. 
Range: 9, 11. 
Site: Dry, sun. 
Fruit: Nutlet. 
A small shrub; commonly occurs on sandy soil; will grow on gypsum deposits. 
Polycodium caesium, see Vaccinium caesium. 
Polycodium floridanum, see Vaccinium caesium. 
Polycodium melanocarpum, see Vaccinium melanocarpum. 
Polycodium neglectum, see Vaccinium neglectum. 
Polycodium stamineum, see Vaccinium stamineum. 
Polygala acanthoclada Gray. Thorn polygala. 
Range: 9, 10. 
Site: Dry, sun. 
Fruit: Capsule. 
A large, spiny, much-branched shrub; forms densely interwoven mounds. 
Not eaten by livestock. 
Polypappus sericeus, see Pluchea sericea. 
Poncirus trifoliata, see Citrus trifoliata. 
Popanax, see Aeacia. 
Popanax schaffneri, see Acacia tortuosa. 
Popanax tortuosa, see Acacia tortuosa. 
Populus spp. 
Commonly large dioecious trees; occur on neutral soils; ordinarily rapid 
growing and short-lived; most cottonwoods appear to be fairly tolerant of 
Salinity, especially P. fremontii. Members of the genus are attacked by the 
Texas root rot caused by Phymatotrichum omnivorum. 
Stomach records (in addition to specific records) : Ten species of birds, in- 
cluding ruffed grouse, dusky grouse, California quail, valley quail, sharp-tailed 
