278 COMPOSITE. (C031POSITE FAMILY.) 



diverging peduncles, 12 - 20-fowered ; achenia short, not tapering at the summit 

 — Open woods : rather common. 



78. NAB ALUS, Cass. Rattlesnake-root. 



Heads few - many-flowered. Involucre cylindrical, of 5 to 14 linear scales in 

 a single row, and a few small bractlets at the base. Achenia short, linear-ob- 

 long, striate or grooved, not contracted at the apex. Pappus of copious straw- 

 color or brownish and rough capillary bristles. — Perennial herbs, with upright 

 leafy stems arising from spindle-shaped (extremely bitter) tubers, very variable 

 leaves, and racemose-panicled mostly nodding heads. Flowers greenish-white 

 or yellowish, often tinged with purple ; in late summer and autumn. (Name 

 probably from ya/3Aa, a harp, in allusion to the lyrate leaves which these plant? 

 sometimes present.) Species of Prenanthes, L. 



* Involucre smooth or nearly so, 5 - 20-Jlowered. 



1. "N. albus, Hook. (White Lettuce. Rattlesnake-root.) Smooth 

 and glaucous (2° -4° high) ; stem corymbose-panicled at the summit: leaves angu- 

 late or triangular-halberd-form, sinuate-toothed, or 3-5-cleft; the uppermost 

 oblong and undivided; involucre (purplish) of about 8 scales, 8 - 1 2-flowered ; 

 pappus deep cinnamon-color. — Var. Serpent Aria is a form with deeply divided 

 leaves, their margins often rough-ciliate. — Borders of woods, in rich soil : 

 common, especially northward. — Stouter and more corymbed than the next, 

 with thickish leaves and often purplish branches. Heads 6'' long. 



2. N. altissimus, Hook. (Tall W.) Smooth; stem tall and slender 

 (3° -6° high) ; the heads in small 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 frequently 3 - 5-parted, with the divisions entire or again cleft ; in- 

 volucre slender (greenish), of 5 scales, o - 6- flowered ; pappus dirty white, or pale 

 straw-color. — Rich moist woods : common northward. 



3. N. Fraseri, DC. (Lion's-foot. Gall-of-the-earth.) Nearly 

 smooth ; stem corymbose-panicled at the summit (l°-4° high) ; leaves mostly del- 

 toid, roughish ; the lower variously 3- 7-lobed, on margined petioles ; the upper 

 oblong-lanceolate, mostly undivided, nearly sessile ; involucre (greenish or pur- 

 plish, sometimes slightly bristly) of about 8 scales, 8- \2 flowered : pappus dull 

 straw-color. — Varies greatly in foliage : the var. integrif6lius has the thick- 

 ish leaves all undivided and merely toothed. — Dry sandy or sterile soil, S. New 

 England to Virginia and southward. 



4. N. nanus, DC. Smooth; stem low and simple (5' -10' high) ; the 

 heads in axillary clusters forming a narrow racemed panicle; leaves triangular- 

 halberd-shaped and very variously lobed or cleft, on slender petioles ; involucre 

 (livid) 10- \3-fowered, of about 8 proper scales and several very short bract-like ones, 

 which are triangular-ovate and oppressed ; pappus straw-color. — Alpine summits, 

 White Mountains of New Hampshire, and Adirondacks, N. New York. 



5. N. Boottii, DC. Stem simple, dwarf (5' -6' high), pubescent at the 

 summit; the heads in an almost simple raceme; lowest leaves halberd-shaped 

 or heart-shaped, the middle oblong, the upper lanceolate, nearly entire, taper- 



