272 GENUS ATRIPLEX. 



Known only from alkaline plains of the southern part of the San Joaquin Valley, Cali- 

 fornia. Type locality, about 25 km. south of Bakersfield, Kern County, California. 

 Collections, all in California: type collection, July 13, 1891, Coville 1235 (UC, US); same 

 locality, Severin and Hall 11782 (UC); plains 13 km. south of Bakersfield, Severin and 

 Hall 11783 (UC); plains south of Bakersfield, Davy 2897 (UC). 



SYNONYM. 

 1. Athiplex cordulata var. tularensis Jepson, Fl. Calif. 436, 1914. — A. tularensis. 



RELATIONSHIPS. 



This species is closely related to A. cordulata, as was expressed by Jepson in the above- 

 quoted combination. Recent and detailed field studies of both species indicate, how- 

 ever, that they are not connected by intermediate forms. In judging from comparisons 

 between the two as they grow under natural conditions, one would scarcely suspect 

 them of being related. Also in detail there is sufficient difference for specific recognition. 

 A. tularensis is a much more slender plant, the leaves are narrower in proportion to their 

 length and never at all cordate at the base as in cordulata, but narrowed below. The 

 shape of leaf is remarkably constant in both species. The fruiting bracts are sometimes 

 very similar in shape, but those of tularensis typically end in an abrupt acute tooth not 

 present in cordulata and both bract and seed are always smaller. 



The small size of the bracts and their shape in some cases are very suggestive of a 

 connection with A. pusilla and its allies. For these reasons A. tularensis was placed in 

 the section Pusillae by Standley (N. Am. Fl. 21 :50, 1916). It seems impossible to deter- 

 mine at the present time whether the direction of evolution was from cordulata through 

 tularensis and then on to the true Pussillae by reduction in essentially all characters, or 

 whether these last have developed from some entirely different source, such as A. wolfi. 



ECOLOGY AND USES. 



Atriplex tularensis grows typically in grassy alkaline flats in the southern portion of the 

 San Joaquin Valley, where it is associated with Distichlis, Elymus condensatus, and Sporo- 

 bolus asperifolius. It extends to the edge of the Salicornia belt, but is absent wherever 

 Salicornia or Spirostachys occurs. It does not form distinct communities, but grows 

 scattered among the grasses, apparently holding its own in the competition. The flowers 

 occur from July to October. 



The plants are grazed along with the grasses, repeated cropping giving them the 

 branched form typical of pastures. They are also hosts of the beet leaf-hopper, but of 

 restricted importance because of the limited range of the species. 



14. ATRIPLEX PUSILLA (Torrey) Watson, Proc. Am. Acad. 9: 110, 1874. Plate 41. 



Smallscale. 



Erect annual herb, 0.5 to 2 dm. high, freely branched throughout but especially at the 

 base ; branches slender, not angled, sparsely furf uraceous, glabrate below, early becoming 

 reddish; leaves all alternate, except 1 or 2 lower pairs, crowded and imbricate above, 

 sessile, ovate or elliptic, narrowed or rounded to the base, acute at apex, 0.5 to 1.5 cm. 

 long, 0.3 to 0.6 cm. wide, entire, thickish, somewhat fleshy, gray with a dense scurf or 

 this sparse and the foliage then greenish, 1-nerved; flowers monoecious, usually 1 in each 

 leaf-axil, sometimes 2, the staminate near the ends of the branchlets but never in naked 

 terminal spikes; perianth either 4- or 5-cleft in the staminate flowers, wanting in the pis- 

 tillate; fruiting bracts sessile, not compressed, united to the apex (united half their length, 

 according to Torrey, but this apparently an error), ovate, abruptly acute, 1 to 1.5 mm. 

 long, about 1 mm. broad, not margined, entire, the faces smooth; seed 0.8 mm. long, yel- 

 lowish-brown (perhaps darker when mature); radicle superior. {Obione pusilla Torrey, 

 in Watson, Bot. King's Expl. 291, 1871.) 



