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 cf many bristle-like squamellae; heads solitary, 



terminating leafy branches. 16. Pappothrix. 



Plant white-floccose. 



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



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 mostcommonlysolitary.peduncled, terminating the branches 

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

 single or in two sultequal 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 

 arose or laciniate squamellae and 1 05 2 (rarely 0) barbellate bristles at the summit of one 

 or both edges. 



Type species, Perityle calif ornica Benth. 



Herbaceous glandular- or arachnf)id-pubescent perennials or annuals. (Ei'pERITylE.) 

 Slender annuals with rather thin leaves. 



Margins of the achenes with distinctly callous margins; ligules yellow 

 or in P. microglossa often white. (Californicae.) 

 Bristle 1, longer than the achene. 



