NATIVE WOODY PLANTS OF THE UNITED STATES 277 
Ulmus fulva Michx. Slippery elm. 
Range: 15, 16, 18, 19, 20, 21, 22, 28, 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. Rock 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 californica (Hook. and Arn.) Nutt. (pl. 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 Urvillea 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 
