IOWA ACADEMY OF SCIENCES. 
277 
Q. marylandica. Muench. Black Jack, a barren Oak. 
Common on dry clay soils. 
Salic ACE iE. Willow Family. 
Salix nigra Marsh. Black Willow. Common along 
river banks. 
S. alba L. White Willow. Introduced; common. 
S. longifolia Muhl. Sandbar Willow. Low ground; 
frequent. 
S. discolor Muhl. Glaucous or Pussy Willow. Damp 
ground; not common. 
S. humilis Marsh. Prairie Willow. Prairies; frequent. 
S. tristis Ait. Dwarf Gray Willow. Hillside thickets; 
not common. 
Pop ulus alba L. White Poplar. Introduced; escaped. 
P. tremuloides Michx. American Aspen. Hot common. 
I have found it only on North Branch, Jefferson 
township. 
P. monilifera Ait. Cottonwood. Necklace Poplar. Com- 
mon along banks of streams. 
Conifers. Pine Family. 
Juniper us virginiana L. lied Cedar. Found on hillsides 
and bluffs of streams; frequent. 
Orchidace^e. Orchis Family. 
Habenaria leucojphcea Gray. Greenish Fringed-Orchis. 
Low prairies; rare. 
Cypripedium parvijlorum Salisb. Smaller Yellow Lady- 
slipper. Rich woods; once very common, but very 
rare now. 
IridacevE. Iris Family. 
Iris versicolor L. Larger Blue Flag. Ponds; very com- 
mon. 
Sisyrinchium angustifolium Mill. Blue-eyed Grass. Open 
woods and meadows; common. 
Amaryllidace^e. Amaryllis Family. 
Ilypo'xis erecta L. Star Grass. Prairies and wild mead- 
ows; common. 
