G. 58] CLASSIFICATION AND DESCRIPTION 121 
stellate hairs; flowers and fruit in long racemes. A beautiful low 
tree, 6 to 12 ft. high; from Japan. Hardy as far north as Philadel- 
phia, but needing a little protection in Massachusetts and Missourt. 
Genus 57. PTEROSTYRAX. 
Similar to Styrax, but with the fruit in panicles, 5- 
winged, conical, and crowned with 
the persistent base of the style. 
Pterostyrax corymbésum, Sieb. 
Leaves deciduous, 2 to 5 in. long, feather- 
veined, petioled, ovate, rarely cordate 
a‘ base, sharply serrate, with stellate 
hairs. Shrub or small tree, 10 to 12 ft. 
high, cultivated from Japan ; with ashy- 
gray bark, and white flowers turning 
yellowish or purplish with age; blooming 
in May, fruit ripe in August. Not per- 
fectly hardy in Massachusetts. 
P. corymbdsum. 
Genus 58. HALESIA. 
Small trees or shrubs with alternate, simple, deciduous, 
serrate leaves. Flowers large, 1 in. long, conspicuous, 
white, hanging, bell-shaped, monopetalous, 4-lobed; bloom- 
ingin spring. Fruit with a single, rough, elongated, bony 
nut surrounded by a 2- to 4-winged coat; ripe in autumn. 
Wood light-colored, very hard and fine-grained. 
1. Halésia diptera, L. (Two-wiIncEp SIL- 
VERBELL TREE.) Leaves large (4 to 5 in. 
long), ovate, acute, serrate, softly pubescent. 
Fruit with 2 conspicuous, broad wings, some- 
times with 2 intermediate narrow ridges. A 
small tree or a large shrub, 
wild in the south, and eul- 
tivated as far north as 
New York City. 
H. diptera. 
2. Halésia tetradptera, L. (FouR-wINGED A 
SILVERBELL TREE.) Leaves smaller(2to4in.), 
oblong-ovate, finely serrate. Fruit smaller, with EH. tetréptera. 
