The Flora of the Cayuga Lake Basin 181 



densely hairy even on the outer surface; leaves subcrenately toothed, some- 

 times 3-lobed at apex on sucker shoots; surface of fruit pubescent. 



3. U. fulva 



c. Twigs of the preceding season dark brown, slightly scabrous or smooth; buds 



less hairy, often glabrous outside ; leaves sharply serrate, often 3-lobed 



toward apex ; surface of fruit glabrous. 4. U. glabra 



b. Seed near the apex of the smaller (12 mm. wide or less), orbicular wing, which 



is notched to the seed ; leaf blade small, 5-8 cm. long ; stamens 3-5 ; twigs 



slender; buds smaller. [U. campestris] 



1. U. americana L. American Elm. 



Alluvial bottom lands and on slopes and uplands, in calcareous gravels and in clays 

 but rarely in light acid chestnut soils ; common. Apr. 1-20. 



Newf. to Man., southw. to Fla. and Tex. ; in river valleys and swamps on the 

 Coastal Plain. 



Variable in habit. Two types may be recognized: the vase type, with strongly 

 ascending main branches which toward the end are arched, recurved, and pendulous- 

 tipped ; and the oak type, with spreading, low-set, stiff er branches. The former type 

 is often " feathered " with twigs on the trunk and the main branches. The vase type 

 is the one used for street planting, and is the more common. Examples of the oak 

 type occur on Turkey Hill and at Summit Marsh. 



2. U. racemosa Thomas. (U. Thomasi Sarg.) Cork Elm. Rock Elm. 

 Bottom lands and slopes, in rich calcareous gravel ; frequent. May 1-10. 



Dry Run, Spencer; Jennings Pond; Inlet Valley, near Lick Brook and Larch 

 Meadow; Six Mile Creek ravine (D. !) ; Mud Creek, Freeville; "conspicuous east of 

 McLean, as tall trees with short branches, thus presenting a columnar aspect" (D. !) ; 

 McLean station (D.) ; Cayuga Lake shore (D. !) ; frequent on the plateau between 

 Cayuga and Owasco Lakes ; and elsewhere. 



W. Que. and w. Vt. to Ont. and Minn., southw. to Ky. and Mo. ; apparently absent 

 in granitic N. E. and on the Coastal Plain. 



The name U. racemosa is apparently valid under the International Rules. 



3. U. fulva Michx. Slippery Elm. 



Slopes of ravines and stream banks, mostly in dry calcareous rocky or gravelly 

 soils; frequent. Apr. 15-May 1. 



Widely distributed throughout the basin except in the acid chestnut soils ; especially 

 abundant along the smaller ravines of the Cayuga Lake shore. 



W. Que. and w. N. E. to N. Dak., southw. to Fla. and Tex. ; rare on the Coastal 

 Plain. 



4. U. glabra Huds. (U. scabra Mill. U. montana With.) Scotch Elm. 



Thickets and ravine banks ; occasional. Apr. 25-May 10. 

 Escaped about Ithaca. Native of Eurasia. 



Peculiar forms are found in cultivation, with smaller, smooth leaves. These may 

 be hybrids with some other species. 



[U. campestris L. English Elm. 



Frequently planted, but doubtfully spontaneous. Native of Eu.] 



2. Celtis (Tourn.) L. 

 1. C. occidentalis L. Hackberry. 



Slopes and bottom lands, in nonacid gravelly and often alluvial soils; infrequent. 

 Apr. 25-May 15. 

 Inlet Valley, w. of Negundo Woods (D. !) and near mouth of Coy Glen; West 



