Hop Hornbeam. Ironwood 293 
and advantagecusly used on light soils for a ground cover in woods, 
standing shade well. 
O. fragrans Lour. (245) (Olea fragrans), is a small tree, eight to ten 
feet, from China, distinguished by its pretty, very fragrant, yellowish- 
white flowers (June), but with less showy foliage; its hardiness ques- 
tionable. It may be grown in pots. 
HOP HORNBEAM. IRONWOOD 
Ostrya. O. Virginica Willd. (245 bis), is a small, native tree, with thin, 
birch-like foliage, turning a fine russet; similar to Carpinus, but of more 
regular outline and branch habit and with more delicate foliage, the 
young twigs reddish (birch-like), the old bark flaky. The pendulous 
green, odd-shaped fruit adds to its ornamental value, which is similar 
to the Hornbeam. Its use is similar to the preceding, the gray bark 
adding to its winter effect. 
O. vulgaris Willd. (carpinifolia) (246), the European species, has 
no special superior points. 
SORREL TREE 
Oxydendron (Andromeda). O.arboreum D C. (247). A beautiful and 
characteristic small tree (fifteen to forty feet), of the Heath family (see 
Shrub), native of the southern Alleghanies, with spreading crown, 
shiny leaves, which turn early into glorious autumn colors; graceful 
sprays of large, white, bell-shaped flowers appear in early summer; 
this tree can be well grouped with Kalmia, Rhododendron, and other 
evergreen shrubs of the kind, showing to especial advantage as the 
center of the group. 
PAULOWNIA 
Paulownia. P.imperialis S. & Z. (248). This is a small to medium- 
sized tree from Japan; of rather straggling, open form, very large and 
tropical-looking, Catalpa-like leaves, and abundant, large, purplish 
blue or violet, most fragrant flowers in stiff, terminal panicles of large 
size (June), followed by nut-like fruit. Striking rather than orna- 
mental, it can be kept in form only by severe pruning, which it stands 
very well, and then its luxuriant fohage is valuable. Cut back to the 
ground every year, it can be readily kept in bush form, making shoots 
