COMPOSITJE 333 



of 20 long-plumose bristles. On high stoney bills, near Stein mountain 

 Southern Oregon . 



Tribe iv Helianthoidese B. & H. Gen. ii, 166. Heads hetarog- 

 amous and the pistillate Howers ligulate and radiate, or rarely with 

 corolla wanting, and then sometimes moncecious: or sometimes homo- 

 gamous by the absence of the ray-flowers: disk-flowers all with regular 

 4-S-toothed tubular corolla. Receptacle usually with palese or chaff 

 subtending either all the flowers or the marginal ones only. Anthers 

 at most sagittate, not caudate at base. Style branches of the herma- 

 phrodite or sterile flowers truncate or continued into a hairy conical 

 to subulate appendage. Pappus various or none: never of truly cap- 

 illary bristles. 



SuBTEiBE I IvE^. Heads androgynous, having few fertile 

 flowers at the margin. 



86 Ira Fertile flowers 1-5, with or without the tube or cup representing 

 a corolla. 



SuBTEiBE II, Ambeosie^. Heads homopamous, moncecious: 

 the fertile ones with 1-4 apetalous flowers in a closed bur-like or 

 achene-like pointed involucre ; the sterile with numerous flowers 

 in an open involucre. 



* Involucre to the staminate flowers 5-12 lobed or almost truncate. 



86 Ambrosia Fertile involucres 1-flowered, achene-like, bearing no more 

 than one row of tubercles or short spines. 



87 Gaertneria Fertile involucres l-4-fl6wered, 1-4-celIed, armed with 

 more than one row of tubercles or prickles. 



* * Involucre of the staminate heads of a few distinct scales. 



38 Xanthlnm Fertile involucres bur-like, 2-celled, 2-flowered, beset with 

 numerous hooked prickles. 



SuBTEiBE III Veebesineje Hcads radiate with either neutral 

 or pistillate ray flowers or rayless : the disk-flowers perfect and 

 fertile. Receptacle chafiy. Achenes thick and 3-4-angled or 

 those of the disk laterally compressed. 



* Uecepta(;le elongated, becoming columnar. 



39 Bndbeckia Kays neutral or rarely wanting: achenes quadrangular 



and compressed. 



* * Beceptacle flat, concave or rarely conical ; 



*■ Bays pistillate and fertile, 



40 Balsamorhlza Pappus none : achenes of the ray obcompressed ; of the 

 disk prismatic-quadrangular or somewhat compressed. 



41 Wyethla Pappus a chaffy-coriaceous crown or cup, continuous with 

 the broad summit of the achene. 



-•- *■ Bays neutral, rarely wanting. 



48 Helianthella Achenes flat, the thin edges more or less wing-like: 

 pappus a pair of persistent awns or chaffy teeth and a crown of inter- 

 mediate chaffy scales. 



