292 GENUS ATRIPLEX. 



24. ATRIPLEX LEUCOPHYLLA(Moquin) Dietrich, Syn. PI. 5: 536, 1852. Plate 45. Seascale. 



Prostrate perennial herb with ascending or erect leafy shoots from an often somewhat 

 woody base, the above-ground portions 1 to 3 dm. high, sometimes forming open mats 

 3 to 10 dm. across; branches stout, obtusely angled when old, often pinkish, coarsely 

 white-mealy, tardily glabrate and the bark then yellowish white ; leaves alternate or those 

 at the base of each shoot opposite, crowded, sometimes loosely imbricated, sessile, orbic- 

 ular-ovate or broadly elliptic or rarely obovate, narrowed or rounded to the base, obtuse 

 at apex, 1 to 3.5 cm. long, 0.5 to 1.5 cm. wide, entire, very thick, densely coated with a 

 permanent brownish or gray scurf, 1- or 3-nerved, sometimes even the midnerve obscure; 

 flowers monoecious, the staminate glomerules in dense stout terminal mostly simple 

 spikes, the pistillate flowers few at a place in the upper axils; perianth 5-cleft in the 

 staminate flowers, wanting in the pistillate; fruiting bracts sessile, spongious, not com- 

 pressed, completely united except at apex, elliptic-globose, acutish, 5 to 7 mm. long, 4 

 to 5 mm. broad, entire or dentate, the faces at least lumpy and commonly with two or 

 several wart-hke projections, not nerved; seed 2.5 to 3 mm. long, very dark reddish 

 brown; radicle superior. {Obione leucophylla Moquin, in DeCandolle, Prodr. 13=':109, 

 1849.) 



Sea-beaches of California and Lower California and the adjacent islands, from Hum- 

 boldt Bay to Viscaino Bay; casual inland at Lake Elsinore. Type locaUty, Cahfornia. 

 Collections, all in California and Lower California: Sand hills of ocean beach at Samoa, 

 opposite Eureka, Tracy 1264 (UC, see minor variations) ; Bucksport, Humboldt Bay, 

 Tracy Ui6 (UC, same variation); Point Reyes, Marin County, Davy 6763 (UC); West 

 Berkeley, December, 1896, Davy (UC); Alameda Marshes, September 24, 1898, Davy 

 (UC); Point Lobos, San Francisco, August 20, 1891, Jepson (Gr, NY, UC, US); Tobin, 

 San Mateo County, August 11, 1913, Brandegee (UC); Monterey, Heller 6858 (UC); 

 Pacific Grove, Elmer 4109 (UC); San Simeon, San Luis Obispo County, July, 1887, 

 Brandegee (UC) ; San Miguel and Santa Cruz Islands (according to Brandegee, Zoe 1 : 145, 

 1890); Ventura Beach, October 19, 1919, Hall (CI); Avalon, Santa Catahna Island, at 

 one locality only, April, 1896, Trask (US, see minor variations); San Nicholas Island, 

 April, 1901, Trask (Gr); San Clemente Island, Nevin and Lyon 29 (Gr); Santa Monica, 

 Davy 2733 (UC); Redondo, October 15, 1893, Brandegee (UC); Lake Elsinore, J. D. 

 Abrams (DS); La Jolla, San Diego County, Clements 57 (Gr, NY, UC); South San Diego, 

 Chandler 4009 (UC); Enseiiada, August 27, 1893, Brandegee (UC); Todos Santos, June 

 2, 1883, Fish (US); Lagoon Head, Palmer 812 (Gr, NY, UC); Coast near Ascension 

 Island, April 17, 1897, Brandegee (UC). 



MINOR VARIATIONS. 



This is one of the least variable of all the North American species. Such variations as occur are due chiefly 

 to differences in size and habit and in the appendages of the bracts. Mrs. Trask has noted an exceptionally 

 small-leaved form at Avalon, Santa Catalina Island. In this the leaves are only 1.2 by 0.5 cm. in size. It is 

 doubtless the result of unfavorable soil conditions or perhaps of inbreeding, for the species is very rare on this 

 island. A specimen with scarcely larger leaves comes from South San Diego {Chandler 4009, UC), while in two 

 collections from Humboldt Bay (Tracy 1264 and 4416, UC), at the northern limit of the range of the species, 

 the leaves are even smaller than in the Santa Catalina Island plant. 



RELATIONSHIPS. 



No direct connection can be traced between this species and any other. It certainly 

 belongs, however, to the group best represented by A. pentandra, A. coulteri, etc. Each 

 of these is more highly specialized than leucophylla in certain particulars, and all of the 

 group have much more reduced and otherwise modified seeds and fruiting bracts. It 

 seems probable, therefore, that leiicophylla had its origin in Mexico and that it became 



