46 NORTH AMERICAN FLORA 
[VoLUME 33 
flowers are alike in sex, and heterogamous when unlike, then the disk-flowers 
usually are hermaphrodite or by abortion of the pistil male, and the marginal 
flowers pistillate or neutral. 
Anthers not caudate at the base. 
Style vernonioid. 
Involucre of distinct, imbricate, or valvate bracts. 
Flowers varying from white to red or blue, never yellow; 
heads discoid (or radiate in some species of Othake, 
with cuneate ligules). 
Achenes not 4-angled and clavate; pappus-squamellae, 
if any, not with strong midribs. 
Achenes 4-angled, clavate; pappus of scarious elongate 
squamellae with strong midribs. (Palafoxianae in) 
Flowers yellow, rarely orange; heads if radiate with linear 
ligules; pappus of numerous capillary bristles. 
Bracts many, in several series, well imbricate. 
Bracts subequal, mostly in a single series. (Genera in) 
Involucre of mostly 5 bracts united into a tube; heads 1- or 2- 
flowered, collected into head-like clusters. 
Style eupatorioid. 
Style asteroid. 
Style senecioid, helianthoid, or rarely inuloid. 
Leaves or bracts, or both, with conspicuous resinous glands. 
Leaves and bracts not with resinous glands (rarely punctate 
with oil-glands). 
Pappus of squamellae or stiff bristles, or coroniform, or 
wanting. 
Involucral bracts not scarious-margined, usually green 
and more or less foliaceous. 
Receptacle chaffy. 
Receptacle usually chaffy throughout. 
Receptacle with a ring of chaff between the ray- 
and disk-flowers. 
Receptacle not chaffy (fimbrillate in Gaillardia and 
Chaenactis). 
Disk-flowers usually sterile; heads 2—8-flowered, 
and leaves opposite or basal; if fertile, the 
ray-corollas actinomorphic, their achenes not 
enclosed by the bracts. 
Disk-flowers usually fertile and ray-corollas ligu- 
late or wanting, or if actinomorphic, their 
achenes enclosed by the involucral bracts (A m- 
blyopappus); if sterile, the heads 8-—many- 
flowered and leaves alternate, pinnatifid 
(Plummera and Blennos perma). 
Involucral bracts with dry 
Pappus squamellate; style helianthoid. 
Pappus coroniform or wanting; style senecioid. 
Pappus, at least in part, of many capillary bristles. 
Involucral bracts imbricate in several series; receptacle 
chaffy. 
Involucral bracts in 1 or 2 subequal series; receptacle 
not chaffy. 
Anthers caudate at base. 
Styles not cynaroid, 7. e., without a ring of longer hairs below. 
Disk-corollas not 2-lipped. 
Pistillate flowers with filiform corollas without ligules. 
Pistillate flowers with ligulate corollas, or heads discoid and 
all flowers hermaphrodite. 
Disk-flowers fertile. 
Style-branches hispid. 
Style vernonioid; 
yellow. 
Style inuloid; heads radiate; corollas yellow. 
Style-branches naked; disk-corollas deeply cleft. 
Disk-flowers hermaphrodite but sterile; pappus none. 
Disk-corollas more or less 2-lipped. 
Style cynaroid, 7. e., with a ring of longer hairs at the base of the 
stigmatic portion; heads discoid or the ray-flowers actinomorphic 
and sterile. 
heads discoid; corollas never 
scarious or hyaline margins. 
Tribe 1. 
Tribe 10. 
Tribe 13. 
Se 
Tribe 
Tribe 6. 
Tribe 2. 
Tribe 3. 
Tribe 11. 
Tribe 8. 
Tribe 9. 
Tribe 7. 
‘Tribe 
‘Tribe 
Tribe 12. 
10. 
Tribe 14. 
Tribe 15. 
Tribe 4. 
Tribe 1. 
Tribe 5. 
‘Tribe 18. 
Tribe 16. 
‘Tribe 19. 
Tribe 17. 
10. 
VERNONIEAE. 
HELENIEAE. 
LIABEAE. 
SENECIONEAE. 
NOCCEAE. 
EUPATORIEAE. 
ASTEREAE. 
TAGETEAE. 
HELIANTHEAE. 
MADIEAE. 
MILLERIEAE. 
HELENIEAE. 
HELENIEAE. 
ANTHEMIDEAE. 
NEUROLAENEAE. 
SENECIONEAE. 
GNAPHALIEAE. 
VERNONIEAE. 
INULEAE. 
GOCHNATIEAE. 
CALENDULEAE. 
MUuTISIEAE. 
CYNAREAE. 
