460 Petrak, Die nordamerikanischen Arten der Gattung Cirsium. 
circiter ramosissimus, ramis plus minnsve 
elongatis polycephalis. Folia radicalia utrinque 
arachnoideo-tomentosa, canescentia vel 
a 1 b i d a , in petiolum anguste alatum remote spinoso-dentatum 
paullatim attenuata, dentibus fere omnino ad spinas reductis, 
ambitu oblonga vel o b 1 o n g o - 1 a n c e o 1 a t a , 
alte sinuato-pinnatif ida, laciniis late ob- 
longis vel ovato-oblongis, apice bi- vel tri- 
dentatis, dentibus triangularibus acumina- 
tis, spinis subvalidis 4 — 6 mm longis strami- 
neis terminatis, margine spinuloso-ciliatis. Folia caulina 
inferiora et media basi late scmiauriculato-semiamplexicauli 
sessilia, plus minusve, saepe fere omnino d e - 
currentia, alis latis vel latissimis, profunde 
spinoso-dentatis, utrinque arachnoideo-tomentosa, canes- 
centia vel albida, ambitu oblongo-lanceolata vel lanceolata ad 
medium vel ad duas tertias fere sinuato-pinnatifida, laciniis inaequa- 
liter bi- vel trifidis, lobis lanceolatis abruptiuscule acuminatis vel 
subobtusis, spinis stramineis, basin versus saepe plus minusve 
purpurascentibus subvalidis, 3 — 6 mm longis terminatis; caulina 
superiora et suprema ambitu e basi ovato-oblonga lanceolata, 
sessilia, breviter decurrentia, ad duas tertias circiter remote vel 
subdense sinuato-pinnatifida, laciniis late triangularibus vel tri- 
angulari-ovatis, ad medium, vel ad basin fere inaequaliter bi- vel 
trifidis, lobis triangularibus vel linearibus, interdum ad spinas 
fere omnino reductis, acuminatis, spinis subvalidis vel validis 
6—10 mm longis terminatis, ceterum ut folia caulina inferiora 
et media. 
Capitula in apice caulis et ramorum raro solitaria, saepe 
2 — 5 aggregata vel subaggregata, breviter 
pedu neu lata vel subsessilia, bracteis 1 — 2 
multo minoribus linearibus, margine spinu- 
loso-ciliatis suffulta, ovato-globosa vel 
o v a t a , raro fere globosa, basi parum dilatata et excavata, 
cum flosculis 24—30 mm longa, 12 — 25 mm lata. Involucri p a r c e 
arachnoidei vel glabrescentis foliola exteriora 
et media e basi ovato-oblonga lineari-lanceo- 
lata, abruptiuscule acuminata, dorso plus 
minusve viscido-carinata, spinulis infirmis 
vel subvalidis stramineis, horizontaliter 
vel erecto-patentibus 1 — 5 mm longis ter- 
minata, interiora et intima multo longiora lineari-lan- 
ceolata, elongato-acuminata, apice plus mi- 
nusve undulato-curvata, interdum fere subscariosa. 
Corollae purpureae, roseae vel albidae limbus vix ad medium 
inaequaliter quinquefidus, laciniis angustis linearibus subobtusis, 
a tubo vix distinctus eoque subduplo longior. Filamenta omnino 
dense longiuscule crispule papilloso-pilosa. Pappus sordide albus, 
flosculis parum brevior, setis plumosis apice interdum tantum 
scabridis, parum vel vix clavellatis. Achaenia matura ovato- 
