668 TREES OF NORTH AMERICA 



cous bracts on upper leafy branchlets of tlie year, the whole inflorescence forming an 

 open tl)yrsus often 5'-6' long and 3'-^' thick, and without leaves toward the apex. 

 Fruit depressed, obscurely lobed, crestless, black, \'-l' in diameter. 



A tree, 18-20 high, with a trunk 5'-G' in diameter, upright branches forming a 

 narrow open head, and slender divaricate angled branchlets pubescent or puberulous 



iSH 



when they first appear, soon glabrous, bright green, ultimately reddish brown, fre- 

 quently terminating in sharp leafless thorn-like points; more often shrubby. Bark 

 of the trunk thin, red-brown, roughened by small closely appressed scales. 



Distribution. A common inhabitant of mountain canons near the coast of Santa 

 Barbara, Ventura, and Los Angeles counties, California; often forming a dense 

 undergrowth in the forest, which it enlivens for many weeks in early spring with its 

 large clusters of bright blue flowers. 



6. COLUBRINA, Brong. 



Trees or shrubs, with terete branches and scaly buds. Leaves petiolate, pinnately 

 veined or triple-veined from the base, often ferrugineo-tomentose on the lower sur- 

 face. Flowers axillary, in contracted few-flowered cymes or fascicles, yellow or 

 greenish yellow; calyx-tube hemispherical, persistent, 5-lobed, the lobes spreading, 

 triangular-ovate, conspicuously keeled on the inner surface, deciduous by a circum- 

 scissile line; disk fleshy, annular, 5-angled or indistinctly 5 or 10-lobed; petals 5, 

 inserted under the margin of the disk, shorter than the lobes of the calyx, cucullate, 

 unguiculate, infolding the stamens; stamens 5, opposite to and inserted with the 

 petals ; filaments incurved ; anthers ovate ; ovary surrounded by and confluent with 

 the disk, 3-celled, subglobose, contracted into a slender 3-lobed style, the obtuse 

 lobes stigmatic on the inner face; ovule erect, from the base of the cell. Fruit sub- 

 globose, 3-lobed; outer coat thin and septicidally dehiscent into 3 1-seeded crusta- 

 ceous nutlets 2-valved at the apex. Seeds erect, broadly obovate, compressed, 3- 

 angled; seed-coat coriaceous, smooth and shining; embryo axile in thick fleshy albu- 

 men; cotyledons orbicular, flat or incurved, thin or fleshy. 



Colubrina with about a dozen species is confined to the tropics, with the largest 

 number of species in the New World. Of the four species found within the terri- 

 tory of the United States one is arborescent in habit. 



