220 Eleventh Annual Report 



2. CELTIS. The Hackberries. 



Trees with leaves with 3 rarely 4-5 primary veins at the base; 

 staminate flowers usually in clusters, pistillate solitary or few to- 

 gether in the axils of the leaves near the end of the twigs; fruit a 

 drupe, ovoid or globose, pulp thin and sweet, frequently remaining 

 on the tree until late winter or early spring; stone bony, wrinkled. 

 In Indiana there are three species commonly not separated. 



Leaves sharply and coarsely serrate, nutlet 6-8 mm. 



(about K inch) long 1 C. occidentalis. 



Leaves entire or nearly so, nutlet 5-6 mm. (about 1/5 

 inch) long. 

 Leaves of a rather broad ovate type, nutlet white, 



shrub or a small tree 2 C. pumila. 



Leaves of an ovate-lanceolate type, nutlet yellowish- 

 white, a large tree 3 C. mississippiensis . 



1. Celtis occidentalis Linnseus. Hackberry. White Hack- 

 berry. Plate 65. Bark on old trees irregularly furrowed, some- 

 times some of the surface warty and rough; fruiting branches smooth, 

 young branches varying from smooth to very hairy; leaves of an 

 ovate type, 6-18 cm. (23^-7 inches) long, usually long taper-pointed, 

 oblique or slightly cordate at the base, margins sharply serrate, 

 leaves on the fruiting branches smooth or nearly so, those on the vege- 

 tative branches more or less rough and more or less hairy on both sur- 

 faces, petioles 0.5-2 cm. (1/5-^ inch) long, more or less hairy above; 

 flowering season April or May; fruit at maturity dark purple or 

 nearly black, borne on stalks usually about one third longer than 

 the leaf stalks; nutlet globose, longer than wide, 6-8 mm. (J^inch) 

 long, 5-6 mm. (1/5 inch) wide, covering light brown. 



Forms with pubescent twigs and leaves with a rough upper sur- 

 face have been distinguished as variety crassifolia (Lamarck) Gray. 

 There are many young trees with rough leaves and pubescent twigs 

 and frequently both pubescent and smooth leaves occur on the same 

 tree. The smooth ones in places exposed to the sun, and the rough 

 ones in the shade of other leaves or other trees. It is believed this 

 character is not constant enough to form a basis of division. A 

 shrubby form with thick leaves of an ovate type, entire or nearly 

 so, is found on the hills in southern Indiana, and is tentatively 

 referred to this species. 



Distribution. Valley of the St. Lawrence south to the Gulf 

 States and west to Texas and Manitoba. Frequent in Indiana 

 along streams and sparingly found in rich bottom lands and on 

 limestone hills. In the greater part of our area it grows to be a 



