iqiqI SARGENT— north AMERICAN TREES 217 



diameter, their scales puberulous, the terminal lobe acute, one- 

 third longer than the rounded lateral lobes. 



A shrub 2-3 m. tall, with dark brown stems and slender gray-brown 

 branchlets thickly covered with resinous glands. 



On the tundra with B. glandidosa in the neighborhood of Dawson, British 

 Alaska, Alice Eastwood, Ten Mile House, June 25, 1914 (no. 367 type); Twenty- 

 four ]\Iile House, June 27, 1914 (no. 400). 



The proper disposition of this plant is doubtful, and it should perhaps 

 be considered a species. The glandular branchlets and slender erect fruiting 

 catkins resemble those of B. glandidosa Michaux, but the larger, acute, sharply 

 serrate leaves are not of that species, and if it is a hybrid the size and serration 

 of the leaves can only have been derived from B. alaskana Sargent. 



Celtis occidentalis L. — On what is usually considered the 

 t}TDe of this species the leaves are broadly ovate, acute or short- 

 acuminate at apex, obliquely rounded at base, coarsely or finely 

 serrate, smooth on the upper surface, glabrous or sparingly pilose 

 along the midribs and veins below, thin, not conspicuously venu- 

 lose; petioles glabrous or rarely puberulous. The fruit is borne on 

 glabrous or rarely puberulous pedicels much longer than the 

 petioles and is subglobose, ellipsoidal, or slightly obovoid, and 

 9-10 mm. in diameter; the stone is only slightly reticulate. The 

 branchlets are glabrous or occasionally pubescent. 



C. occidentalis is distributed from New England to Virginia and westward 

 to Iowa, southwestern Missouri, western and central Kansas, and eastern 

 North Dakota. It is less common and usually a smaller tree than its varieties 

 canina and crassifolia, and much less widely distributed than the latter. All 

 the forms of C. occidentalis are well distinguished by the dark purple fruit, which 

 is larger than that of the other American species; it is borne on longer pedicels 

 than that of our other species, with the exception of that of C. Douglasii. 



Celtis occidentalis var. canina, n. var. — C. canina Rafinesque, 

 Am. Monthly Mag. 2:43. 1817; Planchon, DeCandolle Prodr. 

 17:174. 1873; Britton and Shafer, N. Am. Trees, 355. 1908. — 

 C occidentalis Sargent, Silva N. Am. 7:67 (in part, pi. 317, not 

 Linnaeus). 1895; Hough, Trees N. States and Canada, 193 (in 

 part, fig. 2iy). 1907. — Differing from the type in the usually 

 narrower long-acuminate leaves. 



Extreme forms of this variety look very distinct, but trees with leaves 

 intermediate between these and those of the typical form are common. The 



