CATALOGUE OF PLANTS COLLECTED IN SALTON SINK. 



113 



COMPOSITE— Continued. 



Baccharis glutinosa Pers. 



Common along rivers and about springs in most parts 

 of the Sink. New River bottom near Brawley, 

 Rockwood (8354), and Calexico, Alamo River near 

 Calexico, Thermal, Mecca (8127, 8347), Obsidian 

 Island (MacDougal 44, 113, 204, 302). 



A species extending south and east to Arizona, Colo- 

 rado, and Mexico, and extensively distributed at 

 low altitudes in California; but most abundant in 

 the Colorado Desert. 



Baccharis viminea DC. 



About the moist borders of Dos Palmas Spring (8348). 

 A common species of cismontane southern California, 

 here quite out of its normal range. 



Pluchea camphorata DC. 



About springs and in marshy places in the north- 

 western parts of the Sink. Alkaline flats at Mecca, 

 beach at Mecca (MacDougal 403), Imperial Junc- 

 tion beach (MacDougal 129), Figtree John Spring, 

 Dos Palmas. 



Frequent in like places, at low altitudes, throughout 

 California. 



Pluchea sericea Coville. Arrowweed. 



Very common in river bottoms, about springs, and in 

 damp soils generally, throughout the Sink. Ther- 

 mal, Mecca, Mortmere, Dos Palmas, Rockwood, 

 Imperial, El Centro, Calexico, Penguin Island (Mac- 

 Dougal 201). 



Common in southern California, most abundant in 

 the desert. 



Dicorea canescens T. & G. 



Occasional in moist, subalkaline soil. Indio, as a 



weed in a young date garden (8366), New River 



bottom at Calexico (8365). 

 Colorado Desert and thence into Arizona. 



Hymenoclea salsola T. & G. 



Detrital mesas near Mecca, Rabbit Bay (MacDougal 



209). 

 A common species of the Colorado Desert. 



Ambrosia psilostachya DC. 

 Adventive at Imperial. 



A common weed in California and in many parts of 

 North America. 



Franseria dumosa Gray. Gartneria dumoaa Kuntze. 



Frequent in detrital soil and occasional in light allu- 

 vium. Mecca, Caleb, Durmid, Westmoreland. 



A characteristic species of the Californian deserts, 

 extending into Arizona and Mexico. 



Xanthium commune Britton. 



Frequent throughout Imperial Valley, Calexico, Holt- 



ville, Meloland (W. E. Paccard), Brawley. Also 



at Mecca (8438, 8610). 

 Common in the Colorado bottoms at Fort Yuma; 



not reported otherwise from California, but it 



occurs at San Diego. 



Eci.ii'ta alba Linn. 



In the river bottoms and very common along canals and 

 in irrigated lands in Imperial Valley, and in waste 

 places about the towns of the Sink. Mecca (8362), 

 Rockwood, Brawley, El Centro (8089) , Hoi tville, Mel- 

 oland, Calexico, Obsidian Island (MacDougal 4,303). 



A widely distributed subtropical weed, common along 

 the Colorado River bottoms at Fort Yuma and an 

 entrant into the Sink from the delta. Not before 

 reported from California. 



Bebbia juncea var. aspera Greene. 



Occasional along washes at the upper margin of the 



Sink at its northeastern end. Near Red Canon, 



Dos Palmas. 

 A species of the canons of the desert mountains, which 



barely enters the borders of the Sink. 



8 



COMPOSITE— Continued. 

 Helianthtjs anndus Linn. 



This common California weed is beginning to appear 

 in the fields and towns of Imperial Valley. Braw- 

 ley, Meloland, El Centro. Also at Mecca, rare. 

 Encilia farinosa Gray. 



Occasional on detrital soil at the northeastern end of 



the Sink. Salton, Caleb. 

 A common species of the California deserts, reaching 

 westward into San Bernardino Valley, and east- 

 ward into Arizona. 



Encelia frutescens Gray. 



Rabbit Bay (MacDougal 214). 



A widely distributed species in the caflons of the 

 deserts of California, extending to Arizona and 

 Utah. Here a migrant from the mountains. 

 Encelia eriocephala Gray. 



Common on the plains at Mecca (8345). Obsidian 



Island (MacDougal 33). 

 Abundant in sandy soil in the Mojave and Colorado 

 deserts. 

 BiDENS piLOSA Linn. 



A single plant by the railway at Mecca. 

 Common along ditches and small streams in cismon- 

 tane southern Californi.a, here a waif. 



BiDENS EXPANSA Greene. 



A few plants in the stream from the railway water- 

 works, Mecca (8462). 



An abundant indigenous species of cismontane south- 

 ern California, but here evidently introduce<l. 



Baileya multiradiata Harv. & Gray var. pleniradiata Coville. 

 A single plant in sandy soil, near Meloland (8095). 

 Common at lower altitudes in the California deserts, 

 thence east to New Mexico. 



Baileya pauciradiata Harv. & Gray. 



Meloland (8095), Dixieland (8368). Abundant in 

 places in the mounds near the Alamo River, east of 

 Calexico, and in sand at Travertine Terraces (8430). 



A species of the eastern parts of the Californian deserts 

 and adjacent Arizona and Mexico. 



Palafoxia linearis Lag. 



Indio, as a weed in a date garden, Westmoreland. 

 Abundant in places in the mounds near the Alamo 

 River, where it becomes lignescent at base and 

 more than annual (8364). Sands at Travertine 

 Terraces. 



A widely distributed species of the Colorado Desert, 

 less frequent in the Mojave Desert, and extending 

 into adjacent Arizona and Mexico. 



Pectis papposa Harv. & Gray. 



Frequent in alluvial soil, notably in the mound region 

 of Imperial Valley. Flats near Mecca (8371), bluffs 

 at Rockwood (8370), mounds of the old beach 

 east of Holtville (8083 epappose, 8084 pappose), 

 mounds of the Alamo River east of Calexico, where 

 plentiful in places, in both pappose and epappose 

 forms (8372), streets of Brawley as a weed. 



Southern border of the Colorado Desert, eastward to 

 New Mexico. 



Anthemis cotdla Linn. 



Adventive at a few places in Imperial Valley. Im- 

 perial. 



This old-world weed is common in southern California, 

 whence it has probably been introduced here. 



Peucephalum schottii Gray. 



A few individuals grow in the crevices of Travertine 



Rock and at the base of the range southwest of it 



(8431). 

 This is a characteristic species of the cailons of the 



arid mountains of the Colorado Desert, and enters 



the Sink only under the exceptional circumstances 



here presented. 



