270 ROBINSON. 



Sect. I. Cylindrocephala DC. Heads cylindrical (2-)3-5 times 

 as long as thick, 5-75-flowered; scales man^^-seried, regularly gradu- 

 ated, closely imbricated, concave, firmish in texture, often promptly 

 deciduous, usually pale or stramineous except at the mostly darker 

 often subherbaceous generally obtuse or rounded tip. Receptacle 

 small, flat or nearly so, glabrous. — Prod. v. 141 (1836). Eupatorium 

 ser. Imbricata DC. 1. c. in part. Eupatorium sect. Imbricafa (DC.) 

 Hoffm. in Engl. & Prantl, Nat. Pflanzenf. iv. Abt. 5, 139 (1890). 

 Osmia Sch. Bip. Pollichia, xxii.-xxiv. 250 (1866). Eupatorium sect. 

 Osmia (Sch. Bip.) Benth. ex Bak. in Mart. Fl. Bras. vi. pt. 2, 275 

 (1876). — Chiefly shrubby plants of warm climates. 



Key to Species. 



a. Leaves cordate, sessile or nearly so, deflexed, somewhat rigid, 



bullate above 1. E. buUatum. 



a. Leaves petiolate or cuneately narrowed to a subsessile base b. 

 b. Pedicels sulcate-angulate, glabrous c. 



c. Heads in dense flattish or nioderatelj^ convex corymbs d. 



d. Scales of the involucre oblong, rounded or subtruncate 



or even slightly retuse at the thinnish-margined apex; 



their nerves straight or even slightly diverging at the 



tip; leaves lanceolate, long-acuminate e. 



e. Heads thickish-cylindric to subcampanulate-cylin- 



dric, 45-75-flowered 2. E. pellium. 



e. Heads slender-cj'lindric, about 20-flowered. . . .3. E. Moritzianum. 

 d. Scales ovate-oblong, slightly thickened and with nerves 

 somewhat convergent toward the tij); leaves ovate, 



never long-acuminate 4. E. laevigatum. 



c. Heads in an elongated loose opposite-branched leafy- 

 bracted panicle /. 

 /. Leaves coarsely pellucid-punctate; veinlets scarcely 



at all translucent; heads about 26-flowered. . . .5. E. chrysostictum. 

 f. Leaves not punctate; veinlets forming a translucent 



network; heads about r2-flowered 6. E. diaphanophlebium. 



b. Pedicels pubescent or puberulent (smoothish and essentially 

 terete in E. subscandens) g. 



g. Scales (pale in color) provided at tip with a small l)ut 

 conspicuous lance-linear subherbaceous spreading or 



reflexed appendage 7. E. uromercs. 



g. Scales sometimes changed in texture toward the tip but 

 in no case bearing a narrow appendage /;. 

 /(. Leaves (ovate, never at all rhombic or hastate) 

 rounded at base, petiolate (sometimes in E. colum- 

 hianum abruptly short -acuminate on one or both sides 

 of the insertion from an otherwise rounded base) i. 

 i. Involucral scales dorsally woolh' near the tip. .8. E. columbianum . 

 i. Scales glabrous j. 

 j. Leaves merely acute or acutish. tomentose be- 

 neath, about 2 cm. long; pi^tioles about 3 mm. 

 long 9. E. hijpcricijolium. 



