12 NORTH AMERICAN FLORA [Volume 34 



Pappus of 1 awn but no crown of squamellae; margins of the 

 achenes not ciliate; undershrubs ; appendages of the style- 

 branches subulate. 13. Monothrix. 

 Throat of the disk -corollas cylindric; much exceeding the tube in 

 length; appendages of the style-branches subulate-filiform; peren- 

 nials woody at the base. 14. LepTopharynx. 

 Bracts of the involucre not boat-shaped, neither enclosing the achenes 

 nor double-ribbed on the back. 

 Plant not floccose. 



Pappus absent or of 1 or 2 awns on the angles; heads in naked 



panicles (except one species). 15. Laphamia. * 



Pappus of a crown of many bristle-like squamellae; heads solitary, 



terminating leafy branches. 16. Pappothrix. 



Plant white-floccose. 



Ray-flowers ligulate; plant subacaulescent. 17. EaTonELEA. 



Ray-flowers wanting or with oblique campanulate throat and 3- 



toothed; plant caulescent. 18. Lembertia. 



Bracts in a single series, more or less united. 



Pappus present, of a crown of squamellae and 1 or 2 awns; leaves petioled 



with broad blades. 19. PericomE. 



Pappus wanting; leaves sessile, linear. 20. CrockERIA. 



11. NESOTHAMNUS Rydberg, gen. nov. 



Low white-tomentose shrubs. Leaves alternate, 3-divided and cleft. Heads discoid, 

 numerous in naked corymbs. Involucre hemispheric; bracts oblanceolate in two equal 

 series, boat-shaped, double-ribbed on the back. Flowers all tubular, hermaphrodite and 

 fertile, densely glandular; tube slender, about equaling the deeply campanulate throat; lobes 

 4, ovate. Style-appendages short, acute. Achenes 2-edged, sub-turgid, silky- villous. Pappus 

 of a crown of united squamellae; awns wanting. 



Type species, Perityle incana A. Gray. 



1. Nesothamnus incanus (A. Gray) Rydberg. 



Perityle incana A. Gray, Proc. Am. Acad. 11: 78. 1876. 



A low shrub, 5-10 dm. high; branches densely white-tomentose; leaves alternate; petioles 

 2-4 cm. long; blades 3-5 cm. long, densely white-tomentose, 3-divided, the divisions cuneate, 

 2-3-cleft, lobed and incised; heads numerous, corymbose; involucre hemispheric, 5 mm. high 

 and about 6 mm. broad; bracts oblanceolate, acute, puberulent; disk-corollas 2 mm. long, 

 densely glandular; achenes oblong, about 3 mm. long, sub-turgid, hirsute throughout; pappus 

 scarcely 0.5 mm. long. 



Type locality: Guadalupe Island, off Lower California. 

 Distribution: Guadalupe Island. 



12. PERITYLE Benth. Bot. Voy. Sulph. 23. 1844. 



Galinsogeopsis Schultz-Bip. in Seem. Bot. Voy. Herald 306. 1856. 



Glandular or viscid-puberulent herbs or cinereous slender undershrubs. Leaves opposite 

 or alternate, usually both, petioled; blades mostly ovate or cordate in outline, from nearly 

 entire to deeply dissected. Heads most commonly solitary, peduncled, terminating the branches 

 or rarely few in small corymbs, usually radiate. Involucre hemispheric; bracts narrow in a 

 single or in two subequal series, more or less boat-shaped, somewhat enclosing the marginal 

 achenes, double-ribbed. Receptacle naked, alveolate, flat. Ray-flowers pistillate, fertile; 

 ligules white or yellow, 3-toothed at the apex, deciduous. Disk-flowers numerous, yellow; 

 tube slender, glandular-puberulent; throat campanulate or funnelform, not much, if any, 

 exceeding the tube in length; limb 4- toothed. Achenes oblong or elliptic, strongly compressed, 

 the margins strongly ciliate, often more or less callous-thickened. Pappus of a small crown of 

 erose or laciniate squamellae and 1 or 2 (rarely 0) barbellate bristles at the summit of one 

 or both edges. 



Type species, Perityle californica Benth. 



Herbaceous glandular- or arachnoid -pubescent perennials or annuals. (EupERITYLE.) 

 Slender annuals with rather thin leaves. 



Margins of the achenes with distinctly callous margins; ligules yellow 

 or in P. microglossa often white. (Calif ornicae.) 

 Bristle 1, longer than the achene. 



