BLAKE. — ENCELIA AND RELATED GENERA. 385 



o o Leaves merely puberulent beneath except along the veins; scales gland- 

 ular-hispid. 



10. S. Chaseae (Millsp.) Blake, n. comb. Herbaceous, the base 

 unknown; stem and branches striate, glandular-hispid particularly 

 in the inflorescence; only the lower leaves opposite, thin, ovate-deltoid, 

 acute, broadly wedge-shaped at base, crenate-dentate with blunt 

 teeth, above granular-scabrous, beneath rather softly puberulent and 

 somewhat pilose along the veins, 5-6 cm. long, 3-5.5 cm. wide, nar- 

 rowed into margined glandular-setose petioles 1.5 cm. or less long, the 

 upper sessile and oblong-lanceolate; heads corymbose-paniculate, 

 1-1.2 cm. high; scales somewhat triseriate, the outer ovate-lanceolate, 

 glandular-hispid, shorter than the lance-oblong inner ones which are 

 glandular on back and ciliate toward tip; rays sometimes wanting, 

 when present 8-10, yellow, elliptic, 4-7 mm. long; disk-corollas 5.5 

 mm. long, pubescent, yellow; pales 8-9 ram. long, broad, the margin 

 denticulate, green-ribbed, hispidulous on the keel; achenes 6-7 mm. 

 long, 3.5—4 mm. broad, appressed-pubescent and short-ciliate, bearing 

 two upwardly ciliate awns about half their length. 



Eticelia Chaseae Millsp. in Millsp. & Chase, Field Col. Mus. Pub. 

 Bot. iii. 125, pi. (1904). 



Specimens examined: Yucatan: ruins of Kobah, 26 Nov. 1865, 

 Schoff 911 (type no. 176020, Field Mus.); "herb, 5 feet high, common 

 at Izamal, Oct.," Gaumcr 910 (FG); Chichankanab, Gaumer 2045 

 (F); San Anselmo, Gaumer 2046 (F). 



++ ++ Involucral scales subequal, or the outer if shorter linear-lanceolate to 



lance-oblong. 



= Leaves ovate or ovate-deltoid, unlobed except in S. foetida, the lobes when 



present broad. 



X Leaves not silky-pubescent beneath. 



o Involucral scales herbaceous throughout, scarcely striate; the usually lobed 

 leaves generally broadly auriculate-clasping at base of petiole; achenes 

 small, 4-4.5 mm. long. 



11. S. foetida (Cav.) Blake, n. comb. Annual, erect, often much 

 branched, the stem usually purplish, glandular-puberulent and hispid 

 with tuberculate-based hairs; lower leaves opposite, the upper often 

 alternate, ovate or deltoid, often 3-lobed, particularly the upper, 

 crenate-dentate, acute at apex, broadly cuneate or cordate at base, 

 hispid with tuberculate-based hairs longer along the veins, the blade 

 5-14 cm. long, 3-12 cm. wide, the petioles usually margined, often 

 broadly so, and generally auriculate-clasping at base; heads numerous, 

 panicled, the peduncles glandular-hispid; heads 1 cm. high, radiate; 



