ORDER 70. COMPOSITE. 153 



III. IiA BIATIFLOR^. Corolla of the perfect flowers bilabiate. (C.) 

 TRIBE 7, MULISIACE^E. Style nearly as in Cynarese, the branches obtuse., very convex 



outside : minutely downy at the top No. Ill 



A. SUBORDER TUBULIFLOILE. 



I Heads discoid, that is, without rays... a) 



| Heads radiate, t. e., the outer flowers ligulate.-.(S) 



1 Receptacle naked, '. e., with no pales or bristles among the flowers... (2) 

 1 Receptacle chaffy, bearing pales among the flowers. . .(6) 

 1 Receptacle bearing bristles, or deeply alveolate (honey combed)... (7) 

 2 Pappus a circle of 520 chaffy scales... (a) 

 2 Pappus none, or a short, toothed margin... (&) 

 2 Pappus composed of many capillary bristles... (3) 

 3 Leaves opposite. (Heads homogamous)...(ci) 

 3 Leaves alternate... (4; 



4 Heads homogamous, flowers all perfect... (r) 

 4 Heads heterogamous, flowers not all perfect... (5) 

 5 Scales herbaceous, often deciduous... (e) 

 5 Scales scarious, persistent, often colored... (/) 

 6 Leaves alternate... (.7) 

 6 Leaves opposite... (ft) 



7 Pappus none, or consisting of scales. ..(') 

 7 Pappus composed of many bristles. . .(j) 



8 Receptacle naked (not chaffy), or (in No. 67) deeply honeycomb-celled... (S) 

 8 Receptacle chaffy, with pales among the flowers... (13) 



9 Pappus of 512 scales, which are 1-awned or (in No. 62) cleft-bristly...^ 

 9 Pappus none, or of a few short awns.. .(I) 

 9 Pappus of many capillary bristles... (10) 

 10 Rays cyanic, in a single row. . .(m) 

 10 Rays cyanic, in several rows...(n) 

 10 Rays yellow, in about one row. . .(11) 



11 Pappus double, or of very unequal bristles... (o) 

 11 Pappus simple, the bristles all similar... (12) 



12 Involucre scales imbricated, the outer shorter. ..(p) 

 12 Involucre scales equal, not imbricated... (r) 

 13 Disk and ray flowers both fertile, the latter pistillate. ..(14) 

 13 Disk flowers sterile, ray flowers fertile. . .() 

 13 Disk flowers fertile, ray flowers sterile... (15) 

 14 Raysyellow...(.v) 

 14 Rays cyanic. ..(<) 



15 Achenia obcompressed, often beaked... (c) 



15 Achenia compressed laterally, or not at all. . .(i) 



a Corolla lobes one-sided. Head large, many-flowered StOKESlA. 2 



a Corolla lobes one-sided. Heads 4--5-flowered, aggregated ELEFHAJN-TOPUS 3 



a Corolla lobes equal. Leaves opposite. Pappus awned AQERATUM. 4 



Leaves whorled. Pappus obtuse SCLEROLEFIS. 5 



Leaves alternate. Pappus scales 8 10 PALAFOXIA. 65 



Pappus scales 1220 HYMEXOFAFFUS. 68 



6 Leaves opposite. Flowers dicecious, obscure AMBROSIA. 47 



A Leaves alternate. Flowers yellow. Disk conical MATRICARIA. 73 



Flowers yellow. Disk convex TANACETCM. 74 



Flowers whitish. Erect, leafless above ADENOOADLOIT. 15 



Fls. 8 ....ARTEMISIA. 76 Fta. 9 ....HDMEA. (82 a) 116 



Low and depressed SOLIVA. 77 



c Scales of the involucre in one row. Flowers cyanic CACALIA. 8<J 



Flowers yellow. Receptacle flat SE^ECIO. 87 



Receptacle convex RUOELIA. 89 



c Scaltfi Imbricated. Flowers yellow BIGELOV; i. 27 



Flowers whitish EUPATOKIUM, 10, and KUHMA. 8 



Flowers purple. Pappus simple. Involucre not radiate... LIATRIS. 7 



Pappus simple. Involucre dry, radiate. ..RIIODANTHK. SJ 

 p ; ------ " .... VKRMOMA. I 



