A. ARGENTEA. 283 



SUBSPECIES. 



The characters of this species are subject to a wide range of variation, and it exhibits 

 in consequence a considerable series of striking forms. This has led to the naming 

 of 9 species and varieties segregated from what is here included under A. argenlea. 

 The characters used as bases for these segregates are themselves so variable and occur 

 in so many combinations that many times this number would need to be accepted if 

 one were to recognize all of the forms as they occur in the field. However, by the utiliza- 

 tion of the features that seem to possess the greatest phyletic value, two principal 

 stocks or subspecies may be distinguished. Other forms are better treated as minor 

 variations. 



Key to the Svhspeeies of A triplex argenlea. 



Upper leaves short-petioled or suhsessile. Distribution easterly from Nevada (a) typica (p. 28.3) . 



Upper leaves closely sessile. California to Texas (6) expansa (p. 284). 



21a. Atriplex argentea typica.— Leaves all more or less petioled, the petiole from 

 nearly as long as the blade on lower leaves to almost obsolete on upper ones; blades 

 triangular-ovate or rounded-ovate, often subhastate. {A. argentea Nuttall, 1. c.) In 

 moderately alkaline soil, Saskatchewan to North Dakota, northern New Mexico, Nevada, 

 northeastern California, eastern Oregon, and Idaho; also east to the Mississippi River, 

 perhaps as an introduction. Type locality, on sterile and saline places near the Missouri 

 River. Collections: Southern Saskatchewan, Macoun 1496 (US); Glendive, Montana, 

 September 2, 1892, Sandberg (DS, UC); Yellowstone Valley, Montana, August 19, 

 1898, Setchell (UC); Iroquois, South Dakota, August 11, 1894, Thornber (Gr, NY, UC); 

 eastern Pennington County, South Dakota, Over 1816 (US, minor variation 2, A. capul- 

 medusae Eastwood) ; Upper Louisiana, Nuttall (Phila, "Pursh's specimen, ex-herb. Lam- 

 bert"); Wyoming: Middle Fork Powder River, Johnson County, Nelson 270 (UC); 

 Seven-Mile Lake, Nelson 2796 (R, type of A. volutans Nelson, minor variation 11); 

 Fisher's Ranch, Nelson 5319, 5320 (UC) ; Altamont, extreme southwest, Johnston 2335 

 (UC) ; Albany County, Nelson 8166 (Gr, NY, US) ; 5 km. east of Longmont, northeastern 

 Colorado, not common. Hall 11075 (UC); near Clear Creek and Sloans Lake, Denver, 

 Colorado, Eastwood 54, 104 (UC); Canon City, Colorado, September, 1873, Brandegee 

 (UC) ; Grand Junction, southwestern Colorado, Baker 927 (Gr, UC, US) ; Kiowa Valley, 

 western Nebraska, Rydberg 325 (US, NY); salt-marsh, Lincoln, Nebraska (introduced?), 

 September, 1890, Rydberg (US); Syracuse, Kansas (introduced?), Thompson 145 (Gr, 

 US); San Juan River, Utah, Eastwood 116 (Gr, US, type collection of A. caput-medusae 

 Eastwood, minor variation 2); Aztec ruins, northwestern New Mexico, Hall 11125 

 (UC, same variation); south of Shiprock Station, northwestern New Mexico, Hall 11145 

 (UC, same variation); Navajo Indian Reservation, northeastern Arizona, Standley 

 7446 (US); Winslow, northern Arizona, Hall 11175 (UC); Caliente, southern Nevada, 

 August 7, 1912, Jones (DS); just east of Reno, Nevada, August 11, 1894, Hillman 

 (Herb. Jones, type of A. argentea hillmani, minor variation 1); Peavine, western Nevada, 

 July, 1913, Brandegee (UC, same variation); Truckee River near Vista, Nevada, Hall 

 11027 (UC, same variation); Sierra Valley, northeastern California, Lemmon 1206 (Gr, 

 same variation); Malheur County, Oregon, Cusick 1263 (Gr, US); Pocatello, Idaho, 

 Palmer 536 (US). 



Additional localities in Nevada are cited under minor variation 1. Other stations 

 represented mostly by specimens at the Rocky Mountain Herbarium include north- 

 western Harding County and Fall River County in South Dakota; Hanna, Gardiner 

 River, Meadow Creek, Sheridan, Buffalo, Douglas, Glendo (Laramie County), Big 

 Laramie River, Newcastle (Weston County), and Howell Lakes in Wyoming; Windsor, 



