m DBERG'S COTTONWOOD 



Populus acuminata Rydb. 



The Willow Famih 

 BALK ICEAI 



Habit and Habitat: A medium-sized tree, usually about 111 feel 

 high, with a trunk 10-18 inches in diameter, with several stout, ascend- 

 ing branches which form a compact, round-topped or oval crown, r 



fers the moist soil of stream banks but is often planted as a shade-! 

 on the Great Plains and in the cities and towns of the Rocky .Mountain 

 region. 



Leaves and Buds: The leaves are simple, alternate. rhombic-Ian- 

 abruptly acuminate, gradually or abruptly narrowed and more 



less wedtre-shaped at the base, 01 rarelv broad and rounded at the 



rsely serrate except near tin- apex, dark green and shiny above. 

 dull green beneath, 2-4 inches long, %-2 inches wide, midrib yellow, 



petioles slender. 1 -•"» incbos long. Winter-buds acumina' linous, } :. 



inch long, with 6-7 light, chestnut-brown, shiny seal 



Flowers and Fruits: Flowers produced in April or May. in long, 

 slender catkins; staminate catkins 2-3 inches long, greenish, brs 



numerous, wide, bearing many short dark red stamens: pistillate cat- 

 kins inches long at maturity, pendulous, green, disk cup-shaped; 

 ovary broadly ovate, gradually narrowed above, with large deeply lol 

 and fringed Btigmas. Fruit a dry, leathery capsule or pod. splitting from 

 the apex, borne upon a short stalk, in loosely-fruited pendulous catkins. 

 oblong-ovate, acute, thin-walled, slightly pitted, about 1 .-. inch long. 2-3 

 valved; seeds oblong or ovate, rounded at the tip, light brown, with a 

 tuft of long silky hairs. 



Bark. Twigs and Wood: The bark on young stems and large 

 branches is smooth, nearly white or straw colored, becoming on old 

 trunks pale grayish-brown, and deeply furrowed into broad Mat ridges, 

 about % inch thick. The wood is light brown, with thin nearly white 

 or greenish sapwood, close-grained, tough, weak, not durable; use 1 for 

 fuel, and locally for fence posts. 



Distribution in the State: This is an interesting example of a t> 

 which is very common in the Rocky Mountains but which has just reached 

 the western border of Nebraska where it is sparingly found in the rough 

 country of Scottsbluff county. The species finds in the canyons and 

 valleys of these particular regions conditions which are very similar 

 those which it enjoys farther westward. Map 10. 



Remarks: This Bpecies is called "Rydberg's Cottonwood" after Dr. 



P. a. K; who discovered it and who first gave it the name which 



has been accepted by all botanists for this particular tree. Doctor 



■m instructor in Luther Academy, Wahoo, Nebraska, at 



the time he discovered this species in the early nineties. He has been for 

 many years an authority on the flora of Nebraska and has also studied 

 and published much upon the flora of the Rocky Mountains. He it 

 t. as lie has been for many years, a curator in the New York i 

 ical Garden where he continues his studies of the flowering plants 

 of \..rth America. Rydh ' ttonwood is worthy of wide trial as an 



ornamental tree for • n Nebraska. 



— f,: 



