306 GENUS ATRIPLEX. 



and then pale or stramineous, rarely reddish; leaves alternate, numerous, sessile or sub- 

 sessile, lanceolate, narrowly ovate, or narrowly elliptic, all narrowed to the base, acute 

 or acuminate at apex, mostly 2 to 4 cm. long, 0.4 to 1.5 cm. wide, or up to 8 cm. long by 4 

 cm. wide on vigorous sterile shoots, acutely and sparingly dentate or some entire, thin, 

 scurfy only when young, equally green or greenish on both faces or only slightly paler 

 beneath, strongly 1-nerved; flowers monoecious, the staminate glomerules in naked ter- 

 minal panicles or spikes, these 5 to 15 cm. long or occasionally only 3 or 4 cm. (still more 

 reduced in a hybrid form, minor variation 1), the pistillate flowers in small clusters in 

 nearly all of the leaf-axils; perianth apparently always 5-cleft in the staminate flowers, 

 wanting in the pistillate; fruiting bracts sessile or subsessile, slightly to moderately com- 

 pressed, united to about the middle, cuneate-orbicular or fan-shaped with a narrowed 

 summit, 2 to 2.5 or rarely 3 mm. long, 2 to 3 mm. broad, the margins greenish and acutely 

 dentate above the middle, the faces tuberculate or sometimes smooth, 1-nerved and with 

 also some faint secondary nerves but not reticulated, scarcely scurfy; seed 1 to 1.3 mm. 

 long, brown; radicle superior. (Obione bracteosa Durand and Hilgard, Pacif. R. R. Rep. 

 5': 13, 1858.) 



Alkaline valleys of California from the Sacramento Valley south to the borders of Lower 

 California, very abundant in the San Joaquin Valley and on the coastal slope of southern 

 California, rare east of the Sierra Nevada; grows also in west-central Nevada. Type 

 locality, Poso Creek, Kern County, California. Collections, all in CaUfornia except the 

 last three: Chico, Butte County, Heller 13S50 (SF); Princeton, Colusa County, Septem- 

 ber 14, 1905, Chandler (UC) ; east of Maxwell, Colusa County, Hall 11011 (UC) ; Manteca, 

 San Joaquin County, October 26, 1919, Hall (UC); West Park, near Fresno, October 26, 



1901, Dawes (UC); near Hanford, Tulare County, Kearney 153 (US); Tulare, August, 



1902, Pillsbury (UC); Visalia, September, 1881, Congdon (UC); Rosedale, near Bakers- 

 field, Davy 2886 (UC); near Kernville, Pur-pus 5537 (UC); Lancaster, western part of 

 Mojave Desert, Elmer 3984 (DS, Gr, NY, US); Summerland, Santa Barbara County, 

 Abrams 41 42 (Gr, NY); near Piru, Ventura County, October 20, 1919, Hall (UC); Santa 

 Catalina Island, Eastwood 6529 (SF) ; Cienega, near Los Angeles, Braunton 636 (UC, US) ; 

 near San Bernardino, Parish 21195 (UC); near Riverside, Piemezsei 3765, 3767, 3647 

 (US); near Winchester, Riverside County, April, 1902, Hall (UC) ; Elsinore, July 8, 1896, 

 McClatchie (UC); San Diego, Vasey 554 (US); Needles, Eastwood 5968 (SF); Tecate 

 River, Lower CaUfornia, Mearns 3785 (US); Coronado Islands, on bluffs near the sea, 

 Lower CaUfornia, Cowles 14 (Pomona, minor variation \, A. davidsoni); Reno, Nevada, 

 Petersen 466 (UC). 



MINOR VAJIIATIONS AND SYNONYMS. 



This species exhibits a wide range of vegetative forms, most of which can be correlated with environmental 

 conditions. These include variations in size, dentation, and succulence of leaf and a wide divergence in the 

 habit, this ranging from nearly simple erect plants to widely branched forms which make tangled masses 

 2 meters or more across and sometimes 1 meter high. There is no indication that the root is ever perennial, 

 as has been reported. Three forms which seem to be quite different from the fluctuating variations just 

 mentioned are described under Nos. 1, 4, and 5. 



1. Atriplex davidsoni Standley, N. Am. Fl. 21:57, 1916. — This is exactly like a common small-leaved 

 form of A. bracteom, except that the terminal staminate spikes are reduced to very short, almost globose 

 terminal clusters. The cause of this is not known, but the occurrence of the form only along the coast of 

 southern California, where A. microcarpa also grows, suggest that possibly it may be a hybrid, with this species 

 for the other parent. A rather more noticeable compression of the bracts and the presence of 3 faint nerves 

 on each bract lend support to this view. The collections thus far made show no intergrading series between 

 davidsoni and bracteosa, but a single collection is intermediate. This is Parry 677 (US) in which the staminate 

 inflorescence varies from a globoid cluster to spicate and 2 cm. long. Collections of davidsoni include: Type 

 collections, labeled as Balboa, California, Damdson 2951 (US) but said by Davidson to have been gathered 

 between Balboa and Santa Ana; Temple Street, Los Angeles, Braunton 6S0 (DS, UC, US); Long Beach, Parish 

 (DS, US); Mesmer, Abrams 206 (DS); San Pedro, Eastuvod 166 (SF); Abalone Point, Laguna Beach Bluffs, 

 July 29, Crawford (Pomona, US); Coronado Islands, Crawford H (Pomona). 



