A, DIOECA — A. MONILIFERA. 265 



Osterhout 2637 (NY); Rock Creek Station, Wyoming, August 26, 1881, Ward (US); 

 Teton River country, Montana, Scribner 225 (Gr). Additional localities represented by 

 specimens at the Rocky Mountain Herbarium include Wallace Creek and Sweetwater, 

 Wyoming, northwestern Harding County, North Dakota, and Falls River County, 

 South Dakota. 



MINOR VARIATIONS AND SYNONYMS. 



1. Atriplex endolepis Watson, Proc. Am. Acad. 9: 110, 1874. — The same as A. dioeca. 



2. A. ovATA Clements and Clements, Rocky Mts. Fls., 61, 1917. — ^1 dioeca. 



3. A. sucKLEYANA Rydberg, Mem. N. Y. Bot. Gard. 1 : 134, 1900. — This combination was proposed to avoid a 

 conflict with A. dioeca Rafinesque (Am. Mo. Mag. 2: 176, 1818). However, this latter was only incidentally 

 mentioned by Rafinesque. In any event it would not interfere with the use of the name dioeca 

 by those following the International Code, since Rafinesque had in mind a minor form of A. patula. A. suckley- 

 ana Watson, 1. c, 1 1 1 , 1874, is an entirely different plant, now referred to the genus Suckleya. 



4. Endolepis dioeca Standley, N. Am. Fl. 21:73, 1916. — A. dioeca. 



5. E. OVATA Rydberg, Bull. Torr. Club 30:248, 1903.— The form with ovate 3-nerved leaves usually 

 less than 1 cm. long. Type locality, Buifalo, Wyoming. The Ward specimen cited above belongs here, as also 

 Goodding's 254. In the latter the leaves are 1 to 2 cm. long, mostly 3- or 5-nerved at the base, but some only 

 l-nerved, and is therefore somewhat intermediate to typical dioeca. 



6. E. sucKLEYi Torrey, in Gray, Pacif. R. R. Rep. 12=: 47, plate 3, I860.— Exactly the same as A. dioeca, as 

 indicated by the description and the excellent plate. 



7. KocHiA DIOECA Nuttall, Genera 1 :200, 1818. — The first description of the species. 



8. Salsola dioeca Sprengel, Syst. Veg. 1 : 923, 1825. — A. dioeca. 



RELATIONSHIPS. 



The primitive position of A. dioeca is indicated by the presence of a well-formed 

 perianth in the pistillate flowers. This perianth consists of 3 or 4 scales about as long 

 as the ovary and apparently is never wanting. Because of its presence and the unusual 

 shape of the calyx in the staminate flowers, Torrey, Standley, and others would make 

 this species the type of a distinct genus, namely, Endolepis. The unreliability of the 

 character of the perianth scales is seen in the related A. phyllostegia, where they may 

 be either present or wanting, as will be more fully indicated under that species. These 

 two and A. monolifera constitute a small group of succulent annuals of western North 

 America. They are well separated geographically from one another and none of them 

 is at all abundant. 



ECOLOGY AND USES. 



Atriplex dioeca is a characteristic pioneer in the bad lands of the West. Usually it 

 occurs as small families in rillways or on tiny alluvial fans, but it is also associated with 

 species of Eriogonum or Atriplex to form open colonies. Less commonly it makes a 

 carpet of considerable extent on alkaline soils derived from the Mancos and other 

 shales. The plants bloom from midsummer to fall. This species is usually too sparse 

 and low to be of value even for grazing. 



10. ATRIPLEX MONILIFERA Watson, Proc. Am. Acad. 9:111, 1874. Plate 40. 



Spreading annual herb, the size not known but probably small, branched from the 

 base, the twigs decumbent or ascending; branches leafy, hoary-farinose, doubtless 

 glabrate; leaves alternate, sessile, broadly elliptic or broadly ovate, 0.5 to 1.5 cm. long, 

 0.3 to 1 cm. wide, the upper ones scarcely reduced, broad at the base, obtuse or some- 

 times acute at apex, the margins entire or somewhat repand-dentate, thickish, densely 

 gray-farinose; flowers monoecious, the staminate in approximate glomerules forming 

 terminal moniliform naked spikes, the pistillate flowers solitary in the leaf-axils; perianth 

 of staminate flowers 5-cleft to the middle, each lobe with a thickened ridge down the 

 back, of pistillate flowers described as consisting of 2 minute scales alternating with 



