NATIVE WOODY PLANTS OF THE UNITED STATES 45 



Albizzia julubrissin Duraz. Silktree. 



Range: 29, 30. 



Site: Dry, well-drained, sun, shade. 



Fruit : Legume, available September-November. 



A large tree introduced from Asia and Africa ; 11,000 seeds per pound, 3,000 

 usable plants per pound of seed. 



Alhagi camelorum Fisch. Camelthorn. 



Range: 10, 11. 



Site: Dry, well-drained, sun. 



Fruit: Legume, available August-September. 



A small, spiny shrub naturalized from Asia Minor ; rapid growing ; aggressive 

 and thicket forming; root system deep and extensive; eradication operations 

 for this species have been in progress. 



Allenrolfea occidentalis (Wats.) Kuntze. Inkweed. 



Spirostachys occidentalis Wats. 

 Range: 8, 9, 10, 11, 16. 

 Site : Well-drained, moist, sun. 

 Fruit: Achenelike. 



A small to large, succulent, almost leafless shrub, usually confined to and an 

 indicator of alkaline soil. Sparingly eaten by livestock. 



Alnus spp. Alders. 



Generally rapid growing ; commonly occurring in neutral soil ; wood durable 

 in water ; nitrogen-fixing bacteria form nodules on the roots of alder in some- 

 what the same manner as on the legumes ; propagated by seeds sown in fall 

 or spring; or in the shrubby species, by hard-wood cuttings and layers. 



Stomach records (in addition to specific records) : 20 species of birds, includ- 

 ing sharp-tailed grouse, ruffed grouse, bobwhite, woodcock, and ptarmigan. 

 Composed 2.5 percent of the food of northern sharp-tailed grouse in winter in 

 Quebec and Ontario; Illinois skunk, opossum. Observations (in addition to 

 specific records ) : Sixteen species of birds ; an emergency food of prairie sharp- 

 tailed grouse, northern sharp-tailed grouse ; snowshoe hare, Pacific mountain 

 beaver, brown mountain beaver, porcupine, Olympic wapiti ; beaver, where 

 Populus is lacking ; moose, white-tailed deer. Palatability to livestock not high 

 but considered an important secondary forage, especially for cattle. A source 

 of pollen for bees. 



Alnus alnobetula, see Alnus crispa. 



Alnus crispa (Ait.) Pursh. Green alder. 



A. alnobetula of Amer. auth., not Koch. 

 Range: 26, 27. 



Site : Dry, well-drained, moist, sun. 

 Fruit : Nutlet, borne in a cone. 



A large shrub with somewhat decumbent branches. 



Var. mollis (Fern.) Rehd., (A. mollis Fern.) is a small tree occurring in 

 regions 23, 24, 26, and 27. 



Observations: Redpoll; an important summer browse of moose on Isle Royale. 



Alnus fruticosa, see Alnus sinuata. 



Alnus glutinosa (L.) Gaertn. European black alder. 



A. vulgaris Hill, A. rotundifolia Mill. 

 Range: 26, 27. 

 Site: Well-drained, sun. 

 Fruit : Nutlet, borne in a cone. 



A small tree introduced from Europe, with many varieties known in cultiva- 

 tion; about 10,000 usable plants per pound of seed. 



Observations: Much eaten by ruffed grouse in New York. 



Alnus incana (L.) Moench. Speckled alder. 



Range : 21, 22, 23, 24, 26, 27. 



Site : Well-drained, moist, sun, shade. 



Fruit : Nutlet, borne in a cone, available August-September. 

 A large shrub to small tree with very thick and dense foliage ; rapid growing ; 

 thicket forming; a naturally occurring stream-bank protector; 256,000-625,000 

 seeds per pound, about 10,000 usable plants per pound of seed; easily trans- 

 planted. 



