358 PROCEEDINGS OF THE AMERICAX ACADEMY. 



ENCELIA Adans. (to Christopher Encel, who pubhshed a work on 

 oak-galls in 1577). — Heads small or medium, radiate or rarely discoid, 

 flowers yellow or purple. In^■olucral scales 2-3-rowed, subequal or 

 the outer shorter, lanceolate to ovate-lanceolate. Receptacle convex; 

 pales scarious, soft, embracing the achenes and falling with them. 

 Rays entire or 2-3-toothed or -lo})ed, yellow, rarely absent; disk- 

 corollas with short tube and usually cylindric-funnelform throat, the 

 limb hairy and 5-toothed. St\'le-branches obtuse, short-pubescent 

 outside. Disk-achenes compressed, ver}' flat, oblong or obovate, 

 villous on margins and glabrous or pubescent on the sides, narrowly 

 white-margined, usually pappusless but in some species with two 

 slender upwardly pubescent awns. — Alternate-leaved generally pubes- 

 cent perennials, sometimes frutescent, with solitary to paniculate 

 heads of usually yellow flowers. Type species E. canescens Lam. — 

 About 14 species of western America, in arid regions and on the sea- 

 coast, from Nevada to Lower California and central ^Mexico, and again 

 from Peru to central Chili; one species on the Galapagos Islands. 



Encelia Adans. Fam. ii. 128 (1763). 



Pallasia L'Her. ["Diss. (1784)"] in Ait. Hort. Kew. iii. 498 

 (1789), not of Houtt. 1775, nor Scop. 1777, nor L. fil. 1781, nor 

 Klotzsch 1853 (the last a valid genus of Ruhlaceae, the others all 

 synonyms of various genera). 



Eucalia Raeuschel, Nom. ed. 3. 251, 385 (1797), a nomen nudum. 



Enchelya Lem. in Orb. Diet. Hist. nat. v. 300 (1844). 



Encclya and Enchelia Baillon, Diet. Bot. ii. 517 (1886). 



Key to the Species of Encelia. 



A. Suffrutescent, leaves laciniately lobed. 



B. Leaves linear 1. E. ventorum. 



B. Leaves ovate 2. E. laciniala. 



A. Leaves linear, unlobed. 



B. Heads panicled; plant resinous 14. E. stenophylla. 



B. Heads solitarj^; leafy-stemmed; leaves glabrous beneath. 



12. E. angusiifolia. 

 B. Heads solitary; scapose; leaves puberulent both sides. 



13. E. scaposa. 

 A. Leaves oblong to ovate, unlobed. 



B. Heads paniculate, numerous; branches of inflorescence glabrous. 



3. E. farinosa. 

 B. Heads few or solitary; peduncles pubescent. 



C. Leaves cordate 11. E. Palmeri. 



C. Leaves rounded or cuneate at base. 



D. Shrubby; disk j-ellow. 4. E. frulescens. 



5. E. albescens. 



