56 NORTH AMERICAN FLORA 
Cymes curved; leaf-blades abruptly narrowed to the base; 
pappus white, the scales of the outer series 0.7 mm. long. 
Cymes straight or nearly so; leaf-blades gradually narrowed 
to an obtuse base; pappus pale-brown, the scales of 
the outer series 0.3 mm. long. 
Cymes freely branched, numerous, forming a paniculate or corym- 
biform inflorescence. 
Involucral scales villous with ascending hairs, the middle ones 
triangular-subulate; pappus white. 
Leaf-blades sericeous-hirsute and resinous-dotted beneath. 
Leaf-blades tomentose beneath. 
Involucral scales arachnoid or ciliate, the middle ones acute to 
rounded, not subulate. 
Leaf-blades tomentose or tomentulose beneath; heads 18— 
21- (rarely 13-) flowered. 3 
Achenes pubescent but not glandular; pappus-bristles 
tawny, 4mm. long. 
Achenes glandular and pubescent; 
white or very pale-brown, 6 mm. long. 
Leaf-blades pubescent on the surface beneath with short 
conic hairs. 
Heads 11-flowered. 
Heads 21-flowered; leaf-blades firm in texture, the veins 
reticulate. 
Leaf-blades obtuse or subacute, about two-fifths as 
wide as long, tomentulose above, not olivaceous. 
Leaf-blades acuminate, one-third to one-sixth as 
wide as long, puberulent with conic hairs above, 
olivaceous. 
Heads chiefly or all peduncled, in corymbiform or paniculate clusters, 
never in definitely scorpioid cymes. 
Inflorescence repeatedly and somewhat dichotomously branched, 
the internodes successively and uniformly shorter, producing 
uniform rounded panicles; involucral scales resinous; species 
of Cuba and the Isle of Pines. 
Heads 11—29-flowered. 
Involucre 3—5 mm. high; heads 11—18-flowered; leaf-blades 
scabrellate or scabrous above. 
Leaf-blades oblong-lanceolate to. ovate; 
regularly dichotomous. 
Leaf-blades oblanceolate to obovate; inflorescence ir- 
regularly branched. 
Involucre 5-8 mm. high; heads 18—29-flowered; leaf-blades 
glabrous and usually punctate above. 
Heads 5—6-(rarely 8-) flowered. 
Inflorescence umbelliform, with few to many heads, its branches 
aggregated or separated by short internodes; peduncles all 
about the same length; species of Mexico and Central Amer- 
ica. : 
Principal scales of the involucre 3-8 mm. wide, loosely spread- 
ing at least at the tip. 
Tips of the involucral scales reticulately veined. 
Outer involucral scales appressed at base. 
Leaves green and strigose-pubescent beneath. 
Leaves densely white-tomentose beneath. 
Outer involucral scales foliaceous throughout. 
Tips of the involucral scales not prominently reticulate. 
Leaves prominently reticulate and densely pubescent 
beneath. 
Leaves thinly pubescent to glabrous beneath, not prom- 
inently reticulate. 
Principal scales of the involucre not more than 2 mm. wide. 
Heads with 18 flowers or more; involucres 7 mm. high, or 
pappus-bristles 
inflorescence 
larger. 
Principal involucral scales abruptly rounded and mu- 
cronate. 
7 Principal involucral scales subulate with straight sides 
and prominent midvein. 
Principal involucral scales acute to acuminate, the mid- 
vein not prominent. : 
Leaves thin, not scabrous above. 
Leaves very thick and scabrous. 
Heads with 15 (rarely 18) flowers or less. 
Involucre 7—8 mm. high; inflorescence large, pyramidal. 
Involucre 3-5 mm. high; inflorescence usually broader 
or depressed. 
Pubescence of the lower leaf-surface of floccose to- 
mentum. 
62. 
63. 
64. 
65. 
66. 
67. 
68. 
69. 
70. 
83. 
V. 
[VOLUME 33 
scor pioides. 
V. brachiata. 
Seay OS SS 
SNS 
. canescens. 
. mollis. 
. stellaris. 
. morelana. 
. Aschentborniana. 
. salamana. 
. patens. 
! 
. menthaefolia. 
. cubensis. 
. havanensis. 
. hieracioides. 
. Salvinae. 
. mexicana. 
. callilepis. 
. dictyophlebia. 
. Alamani. 
. Conzatlii. 
. corymbiformis. 
. Karvinskiana. 
. jaliscana. 
. serratuloides. 
. Odxacand,. 
