408 ORDER 70. COMPOSITE. 



ARTIFICIAL ANALYSIS OP THE GENERA. 

 A. SUBORDER, TUBULIFLOR^E. 



S Heads discoid, that is, without rays. (1) 



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

 2 Pappus a circle of 5 20 chaffy scales, (a) 

 2 Pappus none, or a short, toothed margin, (b) 

 2 Pappus composed of many capillary bristles. (3) 

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

 3 Leaves alternate. (4) 



4 Heads homogamous, fls. all perfect, (c) 

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

 5 Scales herbaceous, often deciduous, (e) 

 5 Scales scarions, persistent, often colored, (f) 

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

 6 Leaves alternate, (g) 



6 Leaves opposite, (h) 



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



7 Pappus none, or consisting of scales, (i) 

 7 Pappus composed of many bristles, (j) 



% Heads radiate, i. e., the outer flowers ligulato. (8) 



8 Receptacle naked (not chaffy), or (in No. 67) deeply honeycomb-celled. (9) 

 9 Pappus of 5-12 scales which are 1-awned or (in No. 61) cleft-bristly, (k) 

 9 Pappus none, or of a few short awns. (1) 

 9 Pappus of many capillary bristles. (10) 

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

 10 Kays cyanic, in several rows, (n) 

 10 Kays 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) 

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



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

 14 Rays yellow (a) 

 14 Ray's cyanic, (t) 



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

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



15 Achenia obcompressed, often beaked, (v) 



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



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



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



a Corolla lubes equal Leaves opposite. Pappus awned AGERATUM. 4 



Leaves whorled. Pappus obtuse SCLEROLEPIS. 5 



Leaves alternate. Pappus scales S 10 POLVPTEKIS. 63 



Pappus scales 12 20 HYMEXOPAPPUS. 64 



b Leaves opposite. Flowers dioecious, obscure AMBROSIA. 45 



b Leaves alternate. Flowers yellow. Disk conical ! MATRICARIA. 73 



Flowers yellow. Disk convex TANACETU 



Flowers whitish. Erect, leafless above ADKXOCAULO 



Erect, leafy ARTEMISI 



Low and depressed. SOLIV 



C Scales of the involucre in one row. Flowers cyanic CACALI 



C Scales of the involucre in one row. Flowers yellow SEXECI 



C Scales imbricated. Flowers yellow BIGF.LOVI 



Flowers whitish. EUPATOHIUM 30, and KUIIX 



Flowers purple. Pappus simple LIAI 



Pappus double . . YERXOX . 1 



d Achenia 10-striate. Flowers purple BRJCKELL . 9 



d Achenia 5-angled. Receptacle conical. Flowers blue COXOCLINITT 12 



Receptacle flat. Scales 4 or 5 MIKAXIA. 11 



Scales S 20 . . . .ETTPATORIPM. 10 



