Hackberry 353 



very thin stipules, which fall away early. . The small greenish flowers are polyg- 

 amous or monoecious, borne in the axils of the leaves of the season, the staminate 

 ones clustered, the pistillate either solitary or several together; there is a 4-lobed 

 or sometimes 5-lobed calyx, but no corolla; as many stamens as there are calyx- 

 lobes, their filaments at first curved inward but spreading when the flower ex- 

 pands, those of the pistillate flowers much shorter than those of the staminate. 

 The sessile ovary is i -celled; the style is very short or altogether wanting, and there 

 are 2 recurved narrow stigmas. The fruit is a small smooth globular to oblong 

 drupe, its exocarp pulpy, the endocarp bony. 



Trees of eastern, southern, and middle North America. 

 Leaves not gray-tomentulose beneath, glabrous, or more or less hairy. 

 Leaves thin, not strongly reticulate-veined beneath; eastern trees. 

 Pedicels long, mostly twice as long as the drupe or longer. 



Leaves ovate to ovate-lanceolate; drupe 8 to lo mm. in diameter. 

 Leaves smooth or nearly so above. 

 Leaves acute or short-acuminate; drupe subglobose. i. C. occidentalis. 



Leaves attenuate-acuminate; drupe oblong. 2. C. canina. 



Leaves very rough above; drupe subglobose. 3. C. crassijolia. 



Leaves lanceolate to ovate-lanceolate; drupe 6 to 8 mm. in 

 diameter. 

 Leaves entire, or few-toothed near apex. 4. C. mississippiensis. 



Leaves sharply serrate. 5. C. Smallii. 



Pedicels short, less than twice as long as the drupe. 6. C. georgiana. 



Leaves thick, coriaceous, strongly reticulate-veined beneath; 



western tree. 7. C. reticulata. 



Leaves densely gray-tomentulose beneath, cordate; Texan tree. 8. C. Helleri. 



Northwestern tree; leaves ovate. 9. C. Douglasii. 



I. HACKBERRY — Celtis occidentalis Linnaus 



The Hackberry tree, also known as Sugarberry, inhabits dry hillsides and 

 ledges, ranging from Quebec to North Carolina, westward to Manitoba, Ne- 

 braska, and Oklahoma. It is usually a small tree, and in rocky places sometimes 

 only a shrub, but occasionally becomes 20 meters high, with a trunk diameter of 

 4 to 8 dm. 



The bark is rough, often corky-ridged or warty, thick, gray-brown, and at 

 length scaly. The young branches are slender and vary from smooth to quite 

 hairy; they are fight green at first but become red-brown. As with the elms the 

 buds are all axillary; they are finely hairy and about 6 mm. long. The leaves are 

 thin, ovate to ovate-lanceolate, coarsely toothed to quite entire-margined, 5 to 

 10 cm. long, sharply pointed and on young shoots sometimes long-pointed and 

 much larger; the upper surface is smooth or but little roughened, rather fight 

 green and dull, the under side slightly paler and hairy; the leaf-stalks vary from 

 6 to 16 mm. long, and the finear stipules faU soon after the leaves begin to unfold 

 in the spring. The small green flowers appear with the leaves on shoots of the 



