398 FOREST TEEES OF THE PACIFIC SLOPE. 



Climatic Conditions. — Similar to those of Fremont cottonwood. 



Tolerance. — Moderately tolerant of shade, especially in early life. 



Reproduction. — Prolific seeder, hearing good crop nearly every year. Seed has fairly 

 high rate of germination (but often tardy) and persistent vitality. Germinates well only 

 when covered by moist litter or soil. Reproduction rather scanty. 



Family HI.PPOCASTANACE.ffi. 



Hippocastanacese is known as the horse-chestnut family, which is popular 

 through the wide cultivation for ornament of its best-known representative, 

 the common Grecian horse-chestnut. They are nearly all small or medium-sized 

 trees, which belong chiefly to the genus .Usculus, and, with the similar Mexican 

 and Central American genus Billia, make up the entire family. Characteristics 

 of the family are given under iEsculus, which is well represented in the United 

 States. 



2ESCULUS. BUCKEYES. 



The buckeyes comprise trees, and a few shrubs, which are called " horse-chest- 

 nuts " and "buckeyes;" the latter name, however, is applied to all of our native 

 species. The trees are principally unimportant forest trees, their wood being 

 soft, light, not durable, cross-grained, and hard to work ; a number of them are, 

 however, very highly esteemed and much planted for ornament, on account of 

 their showy flowers and handsome foliage. They are all strikingly similar in 

 the form of their opposite leaves, which are composed of one long stem with 

 from 5 to 9 separate, leaf-like leaflets radiating from its end. The foliage is 

 shed in early autumn every year. The usually large fruits of buckeyes are also 

 similar to each other and easily recognized by their thick, leathery, smooth, 

 warty, or prickly covering (a capsule), which, when mature (in late summer), 

 splits open by regular seams and liberates one or two (often large) thin-shelled, 

 shiny, rich brown, chestnut-like seeds. The fancied resemblance of the big, 

 glossy brown . seeds to the eye of a buck is the probable origin of the popular 

 common name " buckeye." The heavy, fleshy, bitterish seeds, rarely eaten by 

 any animals, are distributed almost entirely by flood waters, whenever carried 

 away from the mother tree. Buried in earth or debris they retain their vitality 

 only until spring, when they germinate, if at all. Winter buds are brown and 

 scaly, those on the ends of the twigs often large and conspicuous. The showy 

 red, yellow, or white (usually erect) clusters of flowers are produced as a new 

 shoot from the ends of last year's twigs. Some of the flowers (on upper part 

 of the cluster) are male or pollen bearing, while others (at the base of the 

 cluster) are bisexual and the only ones producing fruit. Four species occur in 

 the United States ; 3 are in the East, and one in the Pacific region, confined to 

 California. 



California Buckeye. 



Msculus califomica Nuttall. 



DISTINGUISHING CHARACTERISTICS. 



California buckeye is shrub-like ; it has several stems from 10 to 20 feet high 

 and from 3 to 6 inches through, growing together from a common root. Some- 

 times it is from 25 to 30 feet high and from S to 20 inches in diameter, with a 

 short, smooth, gray— often whitish— trunk and a flat-topped, open crown of 

 wide spreading limbs. Leaf-stems from 4 to 5 inches long and commonly with 

 5 (sometimes 4 to 7) leaflets (fig. 1S9), which are from 3 to 7 inches long, 

 smooth throughout when mature, except for minute hairs in the angles of the 

 veins on the paler green lower sides. They fall in early autumn, leaving the 



