FAMILIES OF FLOWERING PLANTS. 81 
grain and color. Next in importance to the wood of the oak is its 
bark, which is very rich in tannin, and hence is employed in the manu- 
facture of dye-stuffs and in tanning. The bark of Quercus Suber, a 
native of southern Europe, furnishes the cork of commerce. Acorns, 
as the fruits of the oak are commonly called, are sometimes eaten as 
food; they afford by their shape and size the surest method of dis- 
criminating between species that otherwise closely resemble each other. 
Fagus, the beech, is another timber tree of great beauty, and often 
forms extensive tracts of forest in our Eastern states and in Europe. 
Like Castanea, the chestnut, it is a small genus, comprising only four 
or five species. The chestnut is undoubtedly the most highly esteemed 
of our native nuts, being equally palatable to the squirrel and the 
small boy. 
It will be noticed that in both Betulaceae and Fagaceae the flowers 
are adapted for wind rather than insect fertilization. This is true to a 
large extent in the families belonging to the following order. 
CHAPTER XV. 
Orders Urticales and Proteales. 
The Urticales have the'flowers 
variously clustered, or rarely even 
solitary, but not borne in ,aments 
as in the Fagales. The fruit is an 
achene,* a drupe or stone-fruit, or 
a berry, never a nut. The order 
consists of three families—U]ma- 
ceae, Moraceae and Urticaceae. 
The order Proteales, which is con- 
fined to the southern hemisphere, 
is restricted to the single. family 
Proteaceae. 
Family Ulmaceae. Elm Fami- 
ly. Contains about 13 genera and 
140 species, of wide distribution in 
° both temperate and tropical re- 
Fic. 66.—The American elm (Ulmus Ameri- 
cana) showing flowers and fruit. After Britton gions. (Of linus,” the’ elm, is noted 
and Brown, Ill. Fl. Northeast U. S. : 
*Achene is a name given to a small dry one-seeded fruit that does not split open 
(indehiscent) when ripe, 
