IOWA ACADEMY OF SCIENCES. 
217 
184. C. hirsutum Mill. (C. pubescens Willd.) Large 
Yellow Lady-slipper. Rare in woods west of 
Fstherville. 
Habenaria Willd. Rein Orchis. 
185. H. leucophcea (Nutt.) A. Gray. Frequent on low 
prairies. 
Gyrostachys Pers. 
1S6. G. cernua (L.) Kuntze. ( Spiranthes cernuOt L. C. 
Richards.) Very rare on low prairies. 
Leptorchis Thouars. 
187. L. loeselii (L.) Mac M. (Liparis loeselii L. C. 
Richards.) Very rare; artificial grove, one and 
one-half miles northeast of Armstrong, where 
it was probably introduced by the birds. It is 
not known from any other locality in the state. 
JUGLANDACEAD. 
JtJGLANS L. 
188. J. nigra L. Black Walnut. This valuable tree 
once quite common along streams, is becoming 
rare. 
Hicoria Raf. 
189. II. minima (Marsh.) Britton. ( Cary a amara Nutt.) 
Bitter-nut. Frequent in woods; our only 
hickory. 
SALICACEiE. 
Populus L. 
190. P. alba L. White or Silver-leaf Poplar. Escaped 
from cultivation; the tree, although a hand- 
some one, can not be recommended, as it 
spreads badly by the roots. 
191. P. tremuloides Michx. American Aspen. Infre- 
quent in woods; rarely in clumps on the 
prairie. 
192. P. deltoides Marsh. (P. monilifera Ait.) Cotton- 
wood. Rare in the native state in several 
localities in the county, but becoming very 
common in cultivation and as an escape in low 
ground. 
