NATIVE WOODY PLANTS OF THE UNITED STATES 277 



Ulmus fulva Michx. Slippery elm. 



Range : 15, 16, 18, 19, 20, 21, 22, 23, 24, 25, 26, 29, 30. 

 Site: Dry, well-drained, sun. 

 Fruit: Samara, available May-June. 



A large tree ; root system deep and spreading ; rapid growing, short-lived ; 

 severely injured by defoliating insects; wood durable, used commercially to 

 some extent; 35,000-75,000 seeds per pound. 

 Observations: Purple finch ; porcupine, cottontail rabbit, white-tailed deer. 



Ulmus racemosa Thomas. Hock elm. 



U. thomasii Sarg. 



Range : 18, 19, 21, 22, 23, 24, 25, 26, 27. 

 Site: Dry, well-drained, sun. 

 Fruit : Samara, available in May. 



A large tree; root system deep when mature; slow growing, rather long- 

 lived ; severely injured by defoliating insects ; wind-firm ; fairly free from 

 fungi ; easy to transplant ; wood used commercially, the most durable of any 

 of the elms. 



Observations: Cottontail rabbit. 



Ulmus serotina Sarg. Red elm. 



Range : 25, 27, 29. 



Site: Dry, well-drained, sun. 



Fruit: Samara, available in November. 



A large tree ; wood hard, tough ; somewhat cultivated ; occurs on limestone 

 and other soils; 149,000 seeds per pound. 



Ulmus thomasii, see Ulmus racemosa. 



Umbellularia calif ornica (Hook, and Arn.) Nutt. (pi. 41, B). Oregon myrtle. 



Range : 1, 4, 5, 10. 



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

 Fruit: Drupe, available in October, somewhat persistent. 

 A small to large shrub or small to large tree; the typical form is a large 

 tree occurring along streams and valley floors ; may be gregarious on north 

 slopes of canyons, forming a very solid cover; dwarf forms, which fruit 

 heavily and form very dense cover, are known to occur in dry chaparral ; pros- 

 trate forms, occurring on ocean bluffs and hillsides, form low, thick, compact, 

 dense mats ; sprouts freely after injury ; fruits abundantly produced ; wood very 

 valuable commercially. 



Stomach records: Steller jay. Observations: Much eaten by Columbian gray 

 squirrels. Of slight importance as browse for mule deer. Roots eaten by hogs. 



Ungnadia speciosa Endl. Spanish buckeye. 



Range: 11, 16, 17, 20, 29, 30. 



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



Fruit: Capsule; available August-October, persistent unopened for 

 a considerable period. 



A large shrub or rarely a small to large tree; occurs on limestone and 

 other soils; not resistant to extremely hot weather; occasionally cultivated. 

 Probably has caused some livestock poisoning, but not commonly taken by 

 livestock except in time of food scarcity. Seeds poisonous to human beings. 

 A source of early honey. 



Urvillea mexicana, see Vrvillea ulmacea. 



Urvillea ulmacea H. B. K. 

 U. mexicana Gray. 

 Range: 17. 



Site: Well-drained, sun. 

 Fruit: Samara. 

 A large vine 



Uva-ursi, see Arctostaphylos. 



Vaccinium spp. Blueberries, huckleberries. 



With one exception, none of these species can be grown on soil containing 

 calcium even in small quantities ; all occur naturally on acid soils. 



Stomach records (in addition to specific records) : Eighty-seven species of 

 birds, including ruffed grouse, sharp-tailed grouse, dusky grouse, southern 



