ELM TRIBES 347 



aa. Leaves not very rough above: fruit oval, deeply notched at the apex. 



U. americana, Linn. Common or white elm. Figs. 96-100, 508. Tall and 

 graceful tree: leaves elliptic-oval, serrate: samara small, more or less hairy 

 on the thin wing, the notch in the apex extending nearly to the seed: flowers 

 hanging on slender stalks. One of the finest of American trees. 



U. racemosa, Thomas. Cork elm. Fig. 509. Smaller tree than the last, 

 with corky-winged branches: leaves with straighter veins: samara with 

 sharp incurved points at the apex: flowers in racemes. Less common. 



U. alata, Michx. Wahoo elm. Small tree, with wide, corky ridges on 

 the branches: leaves small and rather thick, almost sessile, ovate to nearly 

 lanceolate and acute: samara downy, at least when young. Virginia, south 

 and west. 



2. CELTIS. Nettle-tree. Hackberry. 



Elm-lfke in looks, but the fruit a 1-seeded, berry -like drupe: flowers 

 greenish, in the leaf axils, mostly diclinous; calyx 5-6-parted; stamens 5 or 

 6: stigmas 2, very long. 



C. occidentalis, Linn. Common hackberry. Middle-sized tree with 

 rough-furrowed bark: leaves ovate-pointed, oblique at base, serrate: fruit 

 purplish, as large as a pea, edible in the fall when ripe. Low grounds. 



3. MACLURA. Osage Orange. 



Small tree, with dioecious flowers in catkins, 

 and alternate, simple leaves: sterile flowers in 

 raceme-like, deciduous catkins: fertile flowers 

 densely crowded in a head, with 4 sepals and 2 510. Madura pomifera. 

 stigmas, the ovary r ripening into an achene, the 

 whole flower-cluster becoming fleshy and ripening into an orange-like mass. 



M. pomifera, Schneid. (Toxylon pomiferum, Raf.). Osage orange. 

 Fig. 510. Spiny, low tree, much used for hedges, but not hardy in the north- 

 ernmost states: leaves narrow-ovate and entire, glossy: flowers in spring 

 after the leaves appear, the fruit ripening in autumn. Missouri and 

 Kansas south. 



4. MORUS. Mulberry. 



Small to middle-sized trees, with broad, alternate toothed or lobed 

 leaves and monoecious flowers, with 4-parted calyx: stamens 4, witli fila- 

 ments at first bent inward, the staminate catkins soon falling: fertile Bowers 

 ripening a single achene, but the entire catkin becomes fleshy and blackberry- 

 like, and prized for eating. Leaves very variable, often lobed and not 

 lobed on the same branch. 



M. rubra, Linn. Common wild mulberry. Often a large tree in the 

 South: leaves ovate-acuminate, oblique at the base, rough and dull on t In- 

 upper surface and softer beneath, dentate: fruit '-..-l in. long, black-red, 

 sweet. Wood yellow. Most abundant South, but growing as far north as 

 Massachusetts. 



