m 



COMPOSITAE rCOMPOSITE FAMILY) 871 



• * * Heads 5-lS-nowered, racpmoi^e or pnnirulate., commonly ppttduloun • Uavet 

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



^ Involucre cylindrical (at least below the middle)-, bracts ncarious-margimd 

 the outer numerous, short, apprc.ssed. ' 



*+ Involucre of 6-8 primary bracts, S-]2-flowered. 



= Pappus deep reddish-brown. 



6. P. Alba L. (White Lettccr, Rattlesnakk-uoot.) Smootli an<l glau- 

 cous ; stem stout, usually purplish, 0.5-1. 5 m. high, corvnilxw-paiiidt'd at 

 summit; leaves angulate or triangular-halberd-fonn, sinuate-tooth.-d (.r;{-r>-cleft, 

 the uppermost oblong and undivided ; involucre whitish-green :in<i pnrplish' 

 glaucous; flowers whitish. (Xahahis Hook.) — Rich woods and thir-krta 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. (Lion's-foot, Gall-of-tue-earth.) Stem smooth, 

 3-12 dm. high, usually purplish, corymhose-panirlcd at summit; leaves thick, 



variously lobed, often piiinatifid with blunt or rounded lobes, 

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

 clustered at the tips of elongate branches; involucre funnel- 

 form, ciilindric hehno, its subherbaceous green or purplish 

 frequently setulose bracts abruptly spreading above the middle ; 

 flowers purplish, greenish-white, or cream-color; aelienea 

 1035. P. serpen taria. yellow-brown. (Nabalus Hook.)— Dry open soil, e. Mass. 

 Heads x%. to Fla. and Ala. Sept., Oct. Fig. 1035. 



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



8. P. trifoliolata (Cass.) Fernald. (GALL-OF-THK-EAnTii.) 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 scarioiis margins; outer calyculate bracts lance- 

 deltoid, rather firm, with pale hyaline margins, regularly 1086. P. trif..ii..i«ta. 

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

 brown. (Nabalus Cass.; P. serpentaria Man. ed. 6, in i)art, 



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

 mts. to Tenn. Aug., Sept. Fig. IO06. 



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

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

 raceme, rarely somewhat paniculate or subcorymbose ; involucre thick--cylin(lric, 

 glabrous ; bracts lead-color or blackish ; the prijnary ones linear- to lance-oblong, 

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

 bracts ovate to ovate-lanceolate, blacki.'<h-green, herbaceous or fleshy, very 

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

 (Nabalus DC; P. serpentaria, var. Gray; P. trifoliolata, var. Fernald.) — 

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

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



++ ■*-*■ Involucre of 5 primary bracts, f^-C^-flowered. 



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

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

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

 merely toothed or cleft, with naked or winged petioles, or frequeuUy :i-5-parted, 



