434 COMPOSITE. Prenanthes. 



# # * Heads 5-18-flowered, sometimes racemose, usually paniculate, commonly pendulous: 

 leaves diverse, but the cauline nearly all petioled; lower and radical or some of them cordate, or 

 hastate, or truncate at base: root mostly fusiform-thickened or tuberous, as in the preceding: 

 akenes obscurely or minutely striate and sometimes 3-4-costate or angled. 



-1 Involucre cylindraceous, distinctly calyculate with very short and ovate to triangular-subulate 

 appressed scale-like bracts: principal bracts with their covered margins white-scarious in dried 

 specimens. Species variously called WHITE LETTUCE, LION'S-FOOT, RATTLESNAKE-ROOT, 

 GALL-OF-TIIE-EARTH. 



H- Pappus cinnamon-brown: stem tall, generally purplish. 



P. alba, L. Glabrous, often glaucescent, 2 to 5 feet high, rather stout : leaves sometimes all 

 deltoid-hastate and nearly dentate, ou slender winged petioles, or uppermost oblong with 

 tapering base, or most of them 3-5-lobed or parted : inflorescence thyrsoid-paniculate : invo- 

 lucre 8-12- (rarely 5-) flowered, commonly purplish-tinged: flowers dull white: pappus 

 reddish-brown. L. as to Hort. Cliff. & Syu. Pluk., not of herb.; Michx. Fl. ii. 83, in part 

 (not of herb, proper) ; Sims, Bot. Mag. t. 1079 ; Pursli, Fl. ii. 499 ; Bigel. Fl. Bo.st. ed. 2, 286. 

 P. rulticiinda, Willd. Spec. iii. 2537, excl. syn. ; Pursh, 1. c. P. suavis, Salisb. Parad. Loud. 

 t. 85. P. Miamensis, ovata, & proteophylla, Riddell, Syu. W. PI., to be divided between this 

 aud following species. Harpalyce alba, Don ex Steud. ; Beck, 1. c. Nabalus trifoliolatus, 

 Cass. Diet, xxxiv. 95. N. snarls, DC. 1. c. 241. N. albus, Hook. Fl. ii. 294, chiefly; Torr. 

 & Gray, Fl. ii. 480, excl. var. Open oak-woods aud sandy or gravelly ground, Canada and 

 New England to Saskatchewan, Illinois, and the upper country of Georgia, &c. 



-w- -H- Pappus sordid straw-color or whitish: leaves diversely variable, assuming all the forms 

 of the preceding species. 



P. serpentaria, PURSH. Commonly 2 feet high, glabrous or a little hirsute-pubescent : 

 stem sometimes purple-spotted, rather stout : inflorescence corymbosely thyrsoid-paniculate ; 

 the heads mostly glomerate at summit of ascending or spreading flowering-branches or pe- 

 duncles : involucre green, rarely purplish-tinged, 8-12-flowered : flowers purplish, greenish 

 white, or ochroleucous. Fl. ii. 409, t. 24; Ell. Sk. ii. 261. P. alba, L. Spec., as to PI. 

 Gronov. ; AValt. Car. 193; Ell. Sk. ii. 259. Harpalyce serpentaria, Don, 1. c. ; Beck, 1. c. 

 Nabalus trilobatus, Cass. Diet. 1. c. ? N. serpentarius (Hook. 1. c.), N. trilubatus, N. 

 Fraseri, DC. 1. c. (N. ylaucus, Prenanthes glanca, Raf. Fl. Lud. 57, & Eso]>on glaucum, Raf. 

 1. c. 149, has no foundation.) Open grounds, commonly in sandy or sterile soil, New Bruns- 

 wick and Canada to Florida. 



Var. nana. Stem more simple aud strict, 6 to 16 inches high, smooth and glabrous : 

 inflorescence contracted; often sessile or snbsessile clusters of heads in the axils of most of 

 the cauline leaves: involucre livid-greenish. P. alba, var. nana, Bigel. Fl. Bost. 1. c. 

 Nabalus nanus (also N. serpentarius, var. la-i-is), DC. 1. c. ; Torr. & Gray, 1. c. A form with 

 leaves pedately parted into narrow divisions is probably JV. tri/'o/iolatus, Cass. Mountains 

 of N. New England to Canada, S. Labrador, and Newfoundland. 



Var. barbata. Sometimes hirsutulous-pubescent : leaves from oblong to deltoid- 

 hastate, from denticulate to sinuate-lobed, upper not rarely sessile : involucre sometimes 

 sparingly and sometimes copiously beset with bristles. P. crcpiilima. Ell. Sk. ii. 259, not 

 Michx. Nabalus integrifolius (Cass. 1. c. 96, with " subsagittate " leaves), & X. Fraseri in part, 

 DC. 1. c. N. Fraseri, var. integrifolius & var. barbatns, Torr. & Gray, Fl. ii. 481. N. (& 

 Prenanthes) Roanensis, Chickering in Bot. Gazette, v. 155, vi. 191, a mountain form, a span 

 to a foot high, with most of the leaves hastate-deltoid, and bristles on the involucre copious 

 and conspicuous. Mountains of N. and S. Carolina to Alabama; apparently first coll. by 

 Fraser, then by Macbride; the high mountain form by Chickering ou Roan Mountain. Oc- 

 casionally a few of these setose hairs are found on the involucre of ordinary P. serpentaria, 

 and in this variety some heads are almost destitute of them. 



P. altissirna, L. Commonly 3 to 7 feet high, slender, not glaucous, glabrous or nearly so 

 (in open ground sometimes purple-stemmed and hispidulous !) : leaves thin, disposed to be 

 hastate, deltoid, or cordate, sometimes ovate, and denticulate or dentate ; lower not rarely from 

 3-lobed to pedately 5-parted : panicle elongated and loose, very commonly subsessile clusters 

 in the axils of many cauline leaves : involucre narrow-cylindrical, greeuish, always glabrous, 

 5-6-flowered : flowers greenish-ochroleucous. Spec. ii. 797, from char., syn. Pluk. (Aim. 

 t. 317) & Vaill., and perhaps herb. (P. alba, L. herb., specimen from Kalm, is either this or 



