Planer Tree 



35^ 



are rough-hairy and green, but soon become gray or brown and are smooth or 

 nearly so after their first season. The leaves are ovate, oval, or sometimes obo- 

 vate, usually long-pointed, firm in texture, 7 to 18 cm. long, the upper surface 

 exceedingly rough-papillose and dark gxeen, with the veins impressed, the under 

 side usually densely covered with whitish hairs; their edges are sharply and 

 usually coarsely doubly toothed; the stipules fall away soon after the leaves un- 

 fold; the leaf-stalks vary from 3 to 10 mm. in length. The flowers appear in 

 early spring before the leaves, in small, dense clusters; the hairy calyx is lobed to 

 the middle or above, and is about two thirds as long as the stamens; its lobes 

 are blunt. The samaras are short-stalked, oval-orbicular, 12 to 18 nmi. long, 

 hairy over the seed but otherwise smooth, sometimes sHghtly notched, but not 2- 

 beaked as in our other Elms, bearing the 2 very small stigmas. 



The wood is durable in the soil, and is used for sills, posts, and railway- ties; 

 also for implements, tools, and hubs; its specific gravity is about 0.70 and its color 

 is brown or reddish brown. The powdered inner bark is used for poultices. 



II. PLANER TREE 



GENUS PLANERA GMELIN 



Species Planera aquatica (Walter) Gmelin 



Anonymos aquatica Walter 



HE Planer-tree, also called Water-ehn, is the only representative of its 

 genus, and thus known sci- 

 entifically as a monotype. It 

 grows in swamps, ranging 

 from North Carolina to Florida, westward 

 to Kentucky, southern Illinois and Mis- 

 souri to Texas, and much resembles a 

 small-leaved Elm, but may be distin- 

 guished from Ulmus by its fruit, which is 

 a small nut covered with short soft pro- 

 jections, and by its monoecious or some- 

 times polygamous flowers, which appear 

 with the leaves in early spring. It is a 

 small tree, rarely becoming more than 12 

 meters high, and then having a trunk 5 

 or 6 dm. thick. The name Planera is in 

 honor of Johann Jacob Planer, 1743 to 

 1789, who was Professor of Botany in 

 Erfurt. 



Fig. 309. — Planer Tree. 



The thin brown bark falls away in large scales. The buds are very small, 

 roundish, composed of many brown scales. The young slender twigs are reddish 



