EUCALYPTUS TREES. 509 
Pyrus nivalis, Jacquin. —The Snow-pear. Middle 
and South Europe. This would be adapted for or- 
chards in our higher mountain regions. The fruit 
becomes soft and edible through exposure to snow. 
P. amygdaliformis, alar, is probably the wild state 
of this tree. 
Pyrus salicifolia, Linné. — Greece, Turkey, Persia, 
" South-west Russia. Though its fruit, which slowly 
mollifies, is edible, this tree is mainly utilized as a 
superior stock for grafting. 
Quercus densiflora, Hooker and Arnott.—California 
Chestnut-oak. A large evergreen tree, of beautiful 
outline, dense foliage, and compact growth. Bark 
very valuable for tanning ; wood, however, subject 
to rapid decay (Prof. Bolander). Quercus Douglasi 
and Q. lobata are two other tall oaks of California. 
Quercus lobata, Nee.—California. The large acorns 
can be used for food. 
Quercus lyrata, Walter.—The Overcup Oak of the 
South - eastern States of North America, extending 
from South Illinois to Florida and Louisiana. Lately 
recommended as one of the most valuable for timber- 
plantations. 
Quercus phellos, Linné. —The Willow Oak of the 
Eastern States of North America. The acorns ayail- ~ 
able for food, like those of several other species — for 
instance, Q. glabra, Thunb., of Japan. The compar- 
ative value of the numerous cis and trans-atlantic oak 
is but little as yet understood, either for avenue pur- 
poses or timber-plantations, and should be tested with 
care in botanic gardens. Even recently oaks have 
been discovered on the mountains of New Guinea. 
Raphanus sativus, Linné.—South Asia, up to 16,000 
