Olmacee—P lanera. 405 
l. P. Richérdit, syn. P. crendta.—This is a handsome 
deciduous tree from 60 to 80 feet high with oblong deeply 
crenate leaves and smooth deciduous bark. A native of the 
Caucasus, by no means so common in our parks as it deserves 
to be, for it is perfectly hardy, though it rarely flowers in this 
country. 
P. aquatica, syn. P. ulmifolia, is a North American species 
with serrated foliage, of much smaller stature and less hardy. 
P. Japénica is a similar Japanese species recently intro- 
duced. 
8. CELTIS. 
Moderately large trees or shrubs with strongly-nerved leaves, 
fascicled or racemose greenish polygamous or hermaphrodite 
flowers succeeded by small 1-seeded drupaceous fruits. The 
few species described are widely scattered, ranging from the 
Mediterranean region through Central Asia to China. Céltis is 
a classical name for the Lotus. 
1. C. australis. Nettle Tree or Tree Lotus.—A handsome 
tree from 30 to 40 feet high with a straight trunk and 
long slender tough pliant branches. Leaves oblong-lanceolate, 
acuminate, deeply serrate, hispid above, softly pubescent 
beneath, unequal at the base. Fruit black, very sweet and 
edible. A native of the Mediterranean region. 
C.occidentalis, Sugar-berry or Hack-berry, is a very vari- 
able North American species, and includes the forms called 
C. crassifolia, C. pumila, and C. Audibertiana. The ordinary 
form has reticulated cordate-ovate or lanceolate sharply serrate 
leaves and slender-stalked flowers. The variety crassifolia 
is remarkable for its fleshy foliage. 
Orper CIV.—PLATANACEA. 
Highly ornamental deciduous trees with large elegantly 
lobed leaves on long petioles, and conspicuous sheathing 
stipules. Flowers destitute of perianth, moncecious, in separate 
naked spherical bracteolate solitary or clustered catkins, on long 
pendent peduncles. Male flowers with 1 stamen. The 1-celled 
1- or 2-seeded nuts or achenes, are arranged in dense heads. 
The order is restricted to a solitary genus whose few species 
oecur in North Africa, Western Asia, and North America. 
