CATALOGUE OF PLANTS COLLECTED IN SALTON SINK. 



109 



LEGUMINOSiE. 



Prosopis glandulosa Torr. Mesquite. 



A tree of wide distribution in the Sink, occurring 

 wherever its roots are able to reach moist soil. 

 Abundant in the alkaline flats from Indio to Mecca. 

 river bottoms in Imperial Valley, dunes at Indio, 

 and mounds east of Holtville and Calexico, Dos 

 Palmas, Westmoreland, Alamo River near the Mex- 

 ican boundary (8270), Obsidian Island (MacDougal 

 130S), Rabbit Bay (MacDougal 210), Travertine 

 Terraces. 



A common species of the Californian deserts and occa- 

 sional in cismontaue southern California. 



Prosopis pubescens Benth. Strombocai'pus pubescens 

 Gray. Screwbcan. 



Range of the preceding species, except in the dunes. 

 Thermal, Mecca, Caleb, Dos Palmas, Durmid in 

 dry channels of the mesa, Calexico, Rabbit Bay 

 (MacDougal 210), Obsidian Island (MacDougal 30, 

 117), Figtree John, Travertine Terraces. 



A common species of the Californian deserts, thence 

 southward into adjacent Mexico. A single group 

 grows on the dry banks of the Santa Ana River be- 

 tween San Bernardino and Redlands in cismontane 

 southern California. Smaller than the preceding 

 species and apparently able to endure greater 

 aridity. 



Cercidium torreyanum Sarg. Parkinsonia torreyana Wats. 



Palo verde. 

 In detrital soil at northern end of Sink, most frequent 



along washes. Between Mecca and Red Canon, 



Caleb, Travertine Rock. 

 Colorado Desert and adjacent Arizona and Mexico. 



Olneya tesota Gray. 



In detrital soil at northeastern end of the Sink, along 

 or near washes; not seen on the western side. Near 

 Mecca (8123), Mortmere, Dos Palmas. 



Southern part of the Colorado Desert and adjacent 

 Arizona and Mexico. 



Parosela mollis Heller. Dalca mollis Benth. 



Infrequent in arid soil. Mecca (8312, 8450), Dixie- 

 land (8311). 



A common species of the California deserts, but appar- 

 ently infrequent in the Sink. 



Parosela emoryi Heller. Dalca emoryi Gray. 



Widely distributed in arid soils throughout the Sink 

 and notably abundant in the washes and detrital 

 slopes of its northeastern border. Near Mecca, 

 mounds east of Holtville (8080), Caleb, Figtree 

 John, Westmoreland, Obsidian Island (MacDougal 

 16). 



A frequent species of the Colorado Desert. 



Parosela schottii Heller. Dalca scholia Gray. 



Abundant along the washes and on the detrital slopes 



of the northeastern part of the Sink towards its 



upper border. Between Mecca and Red Canon, 



near Dos Palmas. 

 Frequent in the Colorado Desert and eastward into 



Arizona. 



Parosela spinosa Heller. Dalca spinosa Gray. 



Abundant along washes, in the northeastern and 

 northwestern borders of the Sink, and increasingly 

 so towards its upper margin. Mecca, Caleb, Dos 

 Palmas, Figtree John. 



A common species, bordering dry washes and in 

 canons, in the Colorado Desert, extending into 

 Arizona. 



The first leaves of P. spinosa seedlings, 5 to 6 in 

 number, are oblong. 2.5 to 2.75X0.5 to 0.75 cm., 

 glandular-serrate and sparsely guttate-glandular. 

 At the height of about 3 cm. they are succeeded 

 by spines 2 to 2.75 cm. long, sparingly set with 



LEGUMINOSjE— Continued. 



Parosela spinosa Heller. Dalca spinosa Gray — Continued, 

 pointed glands. The whole plantlet is densely ap- 

 pressed-pubescent. 



Sesbania mackocabpa Muhl. 



Along an irrigation canal near Imperial (8306) and 

 said to occasionally occur along other canals. 



At the above station it was spreading into the adjacent 

 irrigated alfalfa field. It was here a weed of culti- 

 vation, brought in by the canals from the Colorado 

 River, in whose delta it is abundant and indigenous. 

 Although not seen along the Alamo or New Rivers, 

 it is not improbable that it may also be a natural 

 entrant. It is a weed in the Government Date 

 Garden near Mecca, where it was sown to test its 

 value as a cover crop, its roots being the host of 

 nitrifying bacteria. 



Melilotds indica All. 

 Adventive at. Imperial. 



A common weed in cold, damp lands in many parts 

 of California. 



Astragalus aridus Gray. 



Coachella (L. A. Greata, Herb. Parish), sandhills 



near Mecca (8467). 

 An endemic annual of the Sink. 



Astragalus limatus Sheldon. 



Frequent in arid soil throughout the Sink. Near 

 Mecca, Caleb, Durmid, between Brawley and 

 Salton Sea (8271), El Centra, Meloland, Holtville 

 (8081), Seelcy, Westmoreland, Calexico. 



It attains a much more luxuriant development when 

 growing in moderately moist soil than in dry. Tra- 

 vertine Terraces (MacDougal 40S, Parish 8429). 



An endemic perennial of the Sink. 



ZYGOPHYLLACEiE. 



Larrea tridentata Coville. Covillea tridenlala Vail. Creo- 

 sote bush. 

 Frequent in arid soil throughout the Sink, but scat- 

 tered and seldom dominant. Caleb, Figtree John, 

 mounds east of Holtville and Calexico, between 

 Calexico and Signal Mountain. Near Westmore- 

 land it occurs in abundance over small isolated 

 tracts. 

 The most characteristic shrub of the entire Lower 

 Sonoran life-area. 



Tkiiutlus terrestris Linn. 



Common along railway tracks throughout their entire 

 length, and extending into the streets of the towns. 

 Indio, Mecca, Durmid, Imperial Junction, Brawley, 

 Imperial, El Centra, Holtville, Calexico. 



This weed has entered California in recent years along 

 the Southern Pacific Railway, and is now common 

 about most railway stations in southern California 

 and spreading in streets of towns. 



GERANACEjE. 



Erodium texanum Gray. 



Plains northwest of Mecca (8449). 

 A common species of both deserts, and eastward to 

 Texas. Also rare in cismontane southern California. 



Erodium cicutarium L'Her. 



In irrigated fields, Mecca (8469). 

 A common naturalized species throughout California, 

 except the deserts and higher mountains. 



EUPHORBIACEiE. 



Croton californica Muell. 



In detrital soil towards the rim of the Sink near Mecca. 

 Abundant northward in the Basin and in many parts 

 of southern California. 



