408 Order 70.— COMPOSITE. 



ARTIFICIAL ANALYSIS OF THE GENERA. 



A. Suborder, TUBULIFLOR^E. 



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



1 Receptacle naked, i. «., with no pales or t>ristles 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 hcterogamous, fls. not all perfect. (5) 

 5 Scales herbaceous, often deciduous, (e) 

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

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

 6 Leaves alternate, (g) 



6 Leaves opposite, (b.) 



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. CI) cleft-bristly, (k) 

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

 9 Pappus of many capillary bristles. (10) 

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

 10 Kays 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) 

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



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

 14 Kays yellow (s) 

 14 Rays 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) 



ft Corolla lobes one-sided. Head large, many-flowered Stokesia. 2 



a Corolla lobes one-sided. Heads 4— 5-flowered, aggregated Eleph antopcs. 3 



a Corolla lobes equal—Leaves opposite. Pap_pus awned Ager atum. 4 



—Leaves whorled. Pappus obtuse Sclerolepis. 5 



—Leaves alternate.— Pappus scales 8—10 Polypteris. 63 



—Pappus scales 12—20 IIymenopappus. 64 



b Leaves opposite. Flowers dioecious, obscure Ambrosia. 45 



b Leaves alternate.— Flowers yellow. Disk conical ! Matricaria. 73 



—Flowers yellow. Disk convex Tanacetcm. 75 



—Flowers whitish.— Erect, leafless above Adenoc aulon. 15 



—Erect, leafy Artemisia. 78 



— Low and depressed Soli va. 77 



C Scales of the involucre in one row. Flowers cyanic Cacalia. 84 



C Scales of the involucre in one row. Flowers yellow Senecio. 88 



C Scales imbricated.— Flowers yellow Bigelovia. 27 



— Flowers whitish. Eupatorirum. Kuiinia. 8 



— Flowers purple. — Pappus simple Liatris. 7 



—Pappus double Vernonia. 1 



d Achenia 10-striate. Flowers purple BriCKELLIA. 9 



d Achenia 5-angled. — Receptacle conical. Flowers blue Conoci.inium. 12 



—Receptacle flat.— Scales 4 or 5 Mikakia. 11 



—Scales S— 20 Ecpatorium. 10 



