POLYMNIA. COMPOSITE. 



371 



Tribe IV. SENECIONIDE^. Less. 

 Heads heterogamous or hcterocephahus {dioecious or moncecious). Style {in the perfect 

 flowers) cyhndraceous above ; the branches linear, someivhat pencillate or hairy at the 

 apex, either truncate or produced beyond the pencillum into a hairy cone ; the stigmatic 

 hnes terminating in the base of the cone or appendage, not confluent.- Leaves opposite 

 or alternate. ■'^ 



CONSPECTUS OF THE SUBTRIBES. 

 Subtribe I. Mel^mpod^e^. Flowers diclinous: the staminate and pisfllatc either occupying the same or different 

 heads, in the same or different plants. 

 . Subtribe II. H^UANTnE^. Heads heterogamous and radiate, or homogamous and discoid. Receptacle partly or en- 

 opposite ^^^"' """^ "" '="''"""''""■ °' '''"""^- ^""»"« blackish, without tails. - Laves often 



Subtribe III. Helenie^. Heads mostly heterogamous. Pappus consisting of numerous distinct scarious chaffy scales 



in a single series, rarely wanting. — Leaves mostly alternate 

 Subtribe IV. Anthemi.e^ Heads mostly heterogamous. Anthers not caudate. Pappus none or coroniform rarely 



cons,sUngo scaes. Branches of the style truncate and bearded at the apex, rarely ,erminatdl,y a 



conical point.— Leaves mostly alternate. "laieu uy a 



Subtribe V. Gnaphalie^. Heads homogamous and discoid, or rarely heterogamous. Anthers caudate. Pappus 



capiUary or setaceous, rarely wanting. — Leaves mostly alternate ^'»ppus 



Subtribe VI. Sen-ec,one.e. Heads homogamous or heterogamous, discoid or radiate. Anthers not caudate Pappus 



capillary, or rarely wanting in the exterior flowers. — Leaves alternate. 



Subtribe I. Melampodine^, DC. Flowers diclinous {none of them perfect); the pistillate 

 and staminate either on different plants {dioecious), or in different heads of the same 

 plant {heterocephalous), or in different fl.oioers of the same head {monaicious\ Anthers 

 not caudate at the base. Receptacle almost always chaffy. Pappus none or somewhat 

 coroniform, never consisting of bristles. 



CONSPECTUS OF THE GENERA. 



* Pleads moncEcious. 



K. Toltmnia. Heads radiate. Achenia ohovoid, not winged. 



17. SiLPnitjM. Heads radiate; the ray deciduous. AchenFa winged, in more than one series. Pappus of 2 teeth or 

 short awns. ''^ ' "' 



la. IvA. Heads not radiate, bracteato, Anthers scarcely united. Receptacle chaffy. Flowers smooth. 



*• Heads heterotcphalous, not radiate. Anthers dislinct. 



19. Ambbosia. Fertile involucre 1-cellcd, 1-fIowercd, not spinous throughout. 



20. Xantiiicm. Fertile involucre 2-celledi "»c scales of the sterile distinct. 



16. POLYMNIA. Linn. ; DC. prodr. 5. p. 514 ; Endl. gen. 2475. leaf-cup 



[Potymnia U the name of one of the Muses; but we know not why Linnaeus applied it to this homely genus.] 



Heads many-flowered ; ihc ray-flowers few, pistillate ; those of the disk tubular, sterile. 

 Scales of the involucre in a double series ; the exterior 4-5, large and foliaceous ; the 

 interior snialler, membranaceous, partly embracing the achenia. Receptacle chafl-y ' flat 



47* 



