lei 
NEW PLANTS FROM NORTH DAKOTA 147 
foliis languescentibus glabrescente, ramis late divaricatis et hor- 
izontalibus quoque et retroflexis paniculate ramosus. Rami 
etiam in lineis longitudinalibus pubescentes, inferiores quidem 
vel medii longitudinem 3 dm. saepe obtinentes. Folia lanceolata 
usque lineari-lanceolata, serrulata vel integra, 0.5—1.5 dm. longa, 
5-17 mm. lata, acuminata, in basin sessilem, 4-5 mm. latam 
attenuata, marginibus ciliatis exceptis glabra. Capitula 20-28 
mm. diametro, numerosa. Involucra ccnica, 5 mm. alta et 5 mm. 
lata. Bracteae in 4 series dispositae, laxae vel apicibus paene 
squatrosis praeditae, lineares, acutae, apicibus autem longe at- 
tenuatis absentibus, cilio-rrarginatae, externae virides, latiores 
internis quae plerumque apices cblanceolatos, virides habent. 
Flores radiati 1-1.2 cm. longi, circiter 45, violacei vel purpureo- 
albi. Pappus sordide albus. 
Stem 7-18 dm. high, with longitudinal lines of pubescence 
decurrent from the leaves, else glabrous, the lower part becoming 
glabrate as the leaves are fading, paniculately branched with 
divaricate and even horizontal and retrcflexed branches, these 
also pubescent in longtudinal lines, and the lower and :middile 
ones often reaching 3 dm. in length. Leaves lanceolate to linear- 
lanceolate, serrulate or entire, 0.5-1.5 dm. long, 5-17 mm. wide, 
acuminate ,narrowed into a sessile, 4-5 mm. wide base, glabrous 
except on the ciliate margins. Heads numerous, 20-28 mm. 
broad. Involucre conical, 5 mm. high and 5 mm. bread. Bracts 
in 4 series, loose or almost squarrose-tipped, linear, acute, but 
without long-attenuate tips, ciliate-margined, outer bracts alto- 
gether green, broader than the inner ones which usually have 
oblanceolate, green tips. Rays 1~1.2 cm. long, about 45, violet or 
purplish-white. Pappus dull white. 
Species apt to be confounded with this are A. longifolius 
Lam., which has a more contracted inflorescence on erect or ascend- 
ing branches, the pubescence on the branches scattered, its bracts 
glabrous, erect, almost equal, imbricated in cnly 1 or 2 series, 
and its pappus pale; A. salictfolins Lam., which has a contracted 
inflorescence on erect or ascending branches, leaves thickish and 
shorter, 0.5-1 dm. long, 0.5—1.5 cm. wide, “ broad-linear or linear- 
oblong bracts with conspicuous elliptic or subrhombric green 
tips’”’ (Gray’s Manual VII., page 803), and pappus white; and 
A. laetevirens Greene, which has broader leaves, fewer heads, bracts 
with white midrib, and outer bracts broader than the inner. 
