C. TERETIFOLIUS. 177 



grooved; twigs brittle, erect, very leafy, glabrous but resinous, at first green (or with a 

 gray bloom) and impressed-punctate, later turning to a rich reddish-brown and becoming 

 striate; leaves terete, obtuse, not mucronate, 1 to 2 cm. long (only moderately shorter in 

 the inflorescence), glabrous but resinous and marked by numerous impressed resin-dots, 

 rarely with a gray waxy bloom ; heads in short terminal spikes, these apparently cymose 

 when very short, or thyrsoid when slightly compound; involucre 6 to 8 mm. high; bracts 

 16 to 20, in 5 sharply defined vertical ranks, oblong, obtuse or the inner ones shortly 

 acute, obscurely carinate, thinnish, glabrous, straw-colored, with a conspicuous green or 

 brownish thickened spot near apex, often terminated by a thick resin-gland; flowers 5 or 

 6; corolla tubular-funnelform, the tube passing gradually to the moderately dilated 

 throat, 6 to 6.5 mm. long, glabrous; lobes lanceolate, about 1 mm. long, erect or the tips 

 slightly recurved, glabrous; anther-tips linear, acute, 0.6 mm. long; style-branches long- 

 exserted, the appendage shorter than or only moderately exceeding the stigmatic portion; 

 achenes slender, slightly tapering from summit to base, 5-angled, about 5 mm.long when 

 mature,densely villous; pappus equaling the corolla or slightly shorter, white. {Linosyris 

 teretifolia Durand and Hilgard, Jour. Acad. Nat. Sci. Phila. II, 3:41, 1855.) 



On gravelly or stony hillsides, often in rocky cafion bottoms from central Nevada west 

 and south to the easterly basal slopes of the Sierra Nevada and Tehachapi Mountains, 

 and San Gorgonio Pass, in California; perhaps also in northern Arizona; most abundant 

 in the White and Inyo Ranges of eastern California. Type locality, all over the moun- 

 tains around Tejon Valley, California. Collections: Pancake Range, Nevada, Purpus 

 6S95 (UC, US); Lida, western Nevada, Hall 10817 (SF, UC); Soda Springs Canon, 

 western Nevada, Shockley 556 (Gr); California: easterly slope of the White Mountains, 

 Hall 10821 (UC); Surprise Canon, Panamint Mountains, Coville and Funston 596 (US); 

 Rosamond Hills, Antelope Valley, Hall 10572 (UC); type collection, September, 1853, 

 Heermann (Gr); San Gorgonio Pass, Parish 655 (Gr). 



SYNONYMS. 



1. BiGELOViA TERETIFOLIA Gray, Proc. Am. Acad. 8:644, 1873. — C. teretifolitis. 



2. Linosyris TERETIFOLIA Durand and Hilgard, Jour. Acad. Nat. Sci. Phila. II, 3:41, 1855. — C. teretifolius. 

 This was the first publication of the species. It was soon repeated in connection with an excellent plate pub- 

 lished by the same authors (Pacif . R. R. Rep. 5' : 9, pi. 7, 1856), but no additional information was there given. 



RELATIONSHIPS. 



There can be no doubt that this species is mostly closely related to C. paniculatus, 

 and it is almost equally certain that it represents a more highly developed type than that. 

 While both are low shrubs of the desert borders, this is much the more abundant and 

 widely distributed, and is thus seen to be a more successful type. The inflorescence is 

 considered as a reduction from the more branching form found in paniculatus, the heads 

 are narrower, with the bracts in more sharply defined vertical ranks, and these bracts 

 show further specialization in the strongly marked apical or subapical green spot with its 

 resinous exudate. All of these characters are taken as indicating an advance over the 

 other species. As in that, the essential features are remarkably constant. The corollas 

 are only slightly more variable than in teretifolius (table 17) and the style-branches much 

 less so. The plants vary much in size and habit, but this is correlated with environmental 

 influences. No species or varieties have ever been proposed as segregates. Such con- 

 siderations indicate that this species is one of the most stable of the genus and that it is 

 not producing mutations or other variations that might serve as the starting point of new 

 evolutionary lines. Its position among the more primitive species is attested by the 

 absence of plasticity, the consequent absence of variations, and the restricted distribu- 

 tion, as well as by the paucity of specialized features. 



