112 



THE SALTON SEA. 



SOLANACEiE— Continued. 



Datura meteloides DC. 



Indio, Mecca; rare. 



Common in southern California, occasionally reaching 

 the western borders of the desert, and reappearing 

 in the bottom lands of the Colorado River at Fort 

 Yuma. 



Nicotiana trigonophylla Dunal. 



A few plants in a wash at Caleb (8333), and three in 



crevices of Travertine Rock. 

 A common chasmophyte in the canons of the desert 



mountains, and occasionally in washes from seed 



carried down by floods. In the Sink only as a rare 



migrant from higher altitudes. 



Nicotiana glauca Graham. 



A single young plant at Mecca (8622) and two at 



Calexico. 

 Common in cismontane southern California, where 

 introduced from Mexico; adventive in the Sink. 



BIGNONIACE.E. 



Chilopsis linearis Sweet. C. saligna Don. Desert willow. 

 A few trees at Caleb, where the seed had evidently 

 been brought down a wash; common in canons and 

 along the courses of washes in the detrital soils of the 

 Basin, but it belongs to higher altitudes than those 

 of the Sink. 



PLANTAGINACE.E. 



Plantaqo lanceolata Linn. 



Abundant in a few lawns at El Centro. 

 A common weed in southern California. 



Plantago fastigiata Morris. 



Abundant on the plains northeast of Mecca (8446). 

 Dried remains collected near Dixieland are prob- 

 ably the same. 



A common species of the Colorado Desert, extending 

 into Mexico. 



CUCDRBITACE^;. 



Cucurbita palmata Wats. Wild gourd. 



Occasional throughout the Sink, notably in washes. 



Mecca, Caleb, Westmoreland. 

 A common species of the Colorado Desert, but most 



abundant in canons. 



LOBELIACE.&. 



Nemacladus adenophorus Parish. 

 On dry mesas. Salton (Hall). 



An ephemeral winter annual of detrital plains, common 

 in both deserts. 



COMPOSITE. 



Hofmeisteria pluriseta Gray. 



A few plants growing in the crevices of Travertine 

 Rock. 



The species is a common chasmophyte of the moun- 

 tains of the Colorado Desert, whence here a 

 migrant. 



Brickellia californica Gray var. desertorum Parish. 



A few plants at the base of the range southwest of 



Travertine Point. 

 Frequent in the desert mountains, from which it is 



here a migrant. 



Heterotheca ghandiploba Nutt. 



Along the boundary-line road near Calexico; evidently 



a recently introduced weed. 

 Indigenous, but more commonly a weed of cultivation, 

 in cismontane southern California. 



COMPOSITE— Continued. 



Isocoma veneta var. acradenia Hall. I. acradenia and I. 

 eremophila Greene. 

 The most widely distributed plant of the Sink, where 

 it is common in both physically and physiologically 

 dry soils. Mecca (8117, and MacDougal 402), 

 Imperial, Westmoreland, Brawley, El Centro, Tra- 

 vertine Terraces (MacDougal 23), Indio (8353), 

 Thermal (8343) in damp alkaline soil, are tall forms, 

 with large branching inflorescence. Mecca (8350), 

 in like soil, has few-toothed leaves and represents 

 the /. eremophila form. Desert between Brawley 

 and Salton Sea, in dry alluvium (8351), has rather 

 broad, entire leaves and agrees with I. acradenia. 

 Dixieland (8353) on artifically moistened alluvium, 

 is 5 cm. tall, the numerous involucres solitary at 

 the summit of pedicels 2 to 5 cm. long. About 

 Durmid and Imperial Junction low forms, with the 

 inflorescence almost capitately condensed, are com- 

 mon. 

 A plant of such wide distribution as Isocoma veneta, 

 and capable of accepting such varied edaphic con- 

 ditions, necessarily responds with a complex of 

 ecological forms. The student who has before him 

 even large suites of herbarium material may be con- 

 tent to define what appear to him valid species, 

 but which field study would convince him could be 

 sustained at most only as more or less uncertain 

 forms and varieties. Treated in this light it might 

 be advantageous to give subspecific names to some 

 of the more marked of these forms, but if too rigidly 

 defined they might be identifiable only with the 

 type specimens. 



Aster spinosus Benth. 



Moist soil along the Alamo and New Rivers, and a 

 pestiferous weed in irrigated lands, in Imperial 

 Valley. New River at Rockwood and Calexico, 

 Brawley, Imperial, El Centro, Meloland, Holtville, 

 Westmoreland. Salton (MacDougal 120), Obsidian 

 Island (MacDougal 202, 203). 

 An entrant from the delta. Known to farmers of 

 Imperial Valley as " wild asparagus," from a resem- 

 blance of its matted roots to those of that vege- 

 table. 



Aster exilis Ell. var. atjstralis Gray. 



A frequent weed about towns and in fields. Thermal, 

 Mecca, Brawley, Imperial, El Centro, Westmore- 

 land, Obsidian Island (MacDougal 306, 413). 



A common weed in California; probably introduced 

 in Imperial Valley by irrigation, as it is the form 

 most abundant in the Colorado River bottoms. 



Erigeron canadensis Linn. 



A frequent weed about towns and in fields. Thermal, 



Mecca (8358), Rockwood, Brawley, El Centro. 

 Common in many parts of California. 



Conyza coulteri Gray. 



In the alkaline flats at the northwest end of the Sink. 



Thermal (8357), Mecca (8356). 

 Occasional at low altitudes in southern California, in 



soil more or less alkaline. 



Baccharis sarothroides Gray. 



Mounds along the old beach at southeastern border 



of the Sink. Near Alamo River east of Calexico 



(8349), and east of Holtville. 

 In California confined to the southern border, and 



thence into Arizona and Mexico. 



Baccharis sergiloides Gray. 



A few shrubs, in subalkaline soil, near Agua Dulce 



(8436). 

 A species of the Colorado and Mojave Deserts, ex- 

 tending into Nevada and Utah. 



