COMPOSITAE COOMPOSITE FAMILY) 871 



** * Heads 5-lS-flowerecl, racemose or paniculate, commonly pendulous ; leaves 

 variable, mostly petiolate, the lower cordate or truncate or hastate at base. 



•^ Involucre cylindrical (at least below the middle) ; bracts scarious-margined, 

 the outer numerous, short, appressed. 



♦♦ Involucre of 6-8 primary bracts, 8-12-Jlowered. 



— Pappus deep reddish-brown. 



6. P. dlba L. (White LETTncB, Rattlesnake-root.) Smooth and glau- 

 cous ; stem stout, usually purplish, 0.5-1.5 m. high, oorymbose-panicled at 

 summit; leaves angulate or triangular-halberd-form, sinuate-toothed or 3-5-oleft, 

 the uppermost oblong and undivided ; involucre whitish-green and purplish, 

 glaucous ; flowers whitish. {Ndbalus Hook.) — Rich woods and thickets, s. 

 Me. to the Saskatchewan, s. to Ga., Ky., and 111. Late July-early Oct. 



= = Pappus whitish or brownish-white. 



a. Primary bracts scarcely as long as the pappus, the small outer ones 



lanceolate. 



7. P. serpentkria Pursh. CLion's-eoot, Gall-of-the-earth.) Stem smooth, 

 3-12 dm. high, usually purplish, corymbose-panicled at summit; leaves thick, 



variously lobed, often pinnatifid vfith blunt or rounded lobes, 

 or even entire, the lower on margined petioles ; heads chiefly 

 clustered at the tips of elongate branches ; involucre funnel- 

 lii^^W form, cylindric below, its subherbaceous greeu or purplish 

 Mp \Jk^ frequently setulose bracts abruptly spreading above the middle ; 



' flowers purplish, greenish-white, or cream-color ; achenes 



1085. P. serpentaria. yellow-browu. (Nabalus Hook.) — Dry open soil, e. Mass. 

 Heads X 2/3. to Fla. and Ala. Sept., Oct. Fie. 1035. 



6. Primary bracts as long as the pappus, the small outer ones deltoid to ovate. 



8. P. trifollolata (Cass.) Fernald. (Gall-of-the-earth.) Glabrous, 1.5-15 

 dm. high ; leaves thinnish, nearly all petioled ; the lower mostly 3-divided or 

 angulate, occasionally uncleft or with the divisions finely dis- 

 sected ; inflorescence an elongate panicle, the heads clustered 

 at the tips of comparatively short ascending branches or in the 

 upper axils; involucre cylindric, glaucous; its pale green or 

 purple-tinged primary bracts linear-lanceolate, acute, the inner 

 with broad scarious margins; outer calyculate bracts lance- 

 deltoid, rather firm, with pale hyaline margins, regularly 1086. P. trifolioiatn. 

 imbricated, the longest 1.5-2.5 mm. long; achenes yellow- Heads x%. 

 brown. {Nabalus Cass.; P. serpentaria Man. ed. 6, in part, 



not Pursh.) — Thickets and woods, Nfd. and Que. to Del., Pa., and along the 

 mts. to Tenn. Aug., Sept. Fig. 1036. 



9. P. naaa (Bigel.) Torr. Stem simple and strict, 0.5-7.5 dm. high ; leaves 

 much as in the preceding, very variable in outline; inflorescence a thyrse or 

 raceme, rarely somewhat paniculate or subcorymbose ; involucre thick-cylindric, 

 "labrous ; bracts lead-color or blackish ; the primary ones linear- to lance-oblong, 

 blunt or'acutish, the inner with narrow scarious margins; outer calyculate 

 bracts ovate to ovate-lanceolate, blackish-green, herbaceous or fleshy, very 

 unequal, the longest 3-6 mm. long; achenes yellowish- to reddish-brown. 

 (Nahalus DC; P. serpentaria, var. Gray; P. trifollolata, var. Fernald.) — 

 Rooky or mossy places, Lab. and Nfd. to the coast of N. S., and the higher mts. 

 of n. N. E. and n. N. T. July-Sept. 



++ ++ Involucre of 5 primary bracts, b-Q-flowered. 



10. P. altfssitna L. Smooth, tall and slender, 1-2 m. high ; heads in small 

 axillary and terminal loose clusters forming a long and wand-lilre leafy panicle ; 

 leaves membranaceous, all petioled, ovate, heart-shaped, or triangular, and 

 merely toothed or cleft, with naked or winged petioles, or frequently 3-5-parted, 



