COMPOSIT.E. 53 



20. XANTHOCEPHALUM. Heads many-flowered, pluriradiate. Involucre broadly 

 campanulate or hemispherical. Kcccptacle fiat or convex. Ligules usually elongated, 

 numerous. Akeues truncate and naked at summit, or edged with a ring bearing a minute 

 coroniform or sijuameUate pappus, or none. Heads larger, solitary at the end of the branch- 

 lets or in open cymes. 



21. GUTIERREZIA. Heads few-many-flowered. Involucre oblong-clavate or turbi- 

 nate to campanulate. Receptacle from plane to conical, commonly alveolate or fimbriUate. 

 Style-appendages mostly slender. Ligules 1 to 8. Akenes short, obo\ ate or oblong, terete 

 or 5-angled. Pappus pluripaleaceous, but the pale* often reduced to a crown or miuute, in 

 the ray commonly smaller and sometimes wanting. Heads small, paniculate or cymose- 

 clustered. Disk-flowers, or some of the central ones, uccasi(mally infertile. 



22. AMPHIACHYRIS. Heads few-mauy-rtowered ; the ray-flowers only fertile ; those 

 of the disk hermaphrodite or subhermaphrodite but infertile. In\olucre, &c. of Gutierrezia. 

 Style-appendages lanceolate; the stigmatic lines below them indistinct or obsolete. Fertile 

 akeues pubescent. Pappus of the ray-fluwcrs obsolete or coroniform, or of a few setiform 

 S([uamella; ; of the disk setiform-paleaceous, viz. of 5 to :2n aristiform palese or weak bristles 

 more or less dilated and united at base, nearlv equalling the corolla. 



33. BRACHYCH^TA. Heads, ic. as in Solidarjo. Pappus both in the ray and disk of 

 bristles abbreviated to siiuamelkc. 



* * Pappus pauciaristate, i. e. of few (less than 10) elongated awns or rigid bristles, some- 

 times caducous or wanting : heads radiate or in same genus rayless, solitary at the end 

 of the brandies. 



23. GRINDELIA. Involucre many-flowered, hemispherical or at first globose ; its bracts 

 numerous and narrow, imbricated in many series, firm and rigid, with more or less herbaceous 

 tips. Style-appendages lanceolate or linear. Akenes sliort and thick, compressed or turgid, 

 or the outer triangular, truncate, glabrous. Pappus of 2 to 8 caducous nearly smooth awns 

 or corneous bristles. 



24. PENTACH-^TA. Involucre many-several-flowereil, hemispherical or campanulate, of 

 thiu and scarious-maxgined appressed lirncts, destitute of herbacei.'us tips, commonly tipped 

 with a delicate mucro. Style-appendages filiform-subulate, hisi)id. Akeues oblong to fusi- 

 form-oboiate, somewhat compressed and villous. Pappus of mostly 5 (rarely 3 to 6 or 

 even 8) slender and persistent scabrous bristles with somewhat enlarged base, sometimes 

 reduced to this base, or even this obsolete. Eeceptacle sliort-alveolate. liays either yellow, 

 or white or pink ! 



* * * Pappus multisetose in either the disk or ray, but not in both, and akenes of disk 

 and ray unlike. 



25. BRADBURIA. Involucre campanulate, of rather broad and thin scarioasly margined and 

 mucronate-actrminate apjiresscd bracts. Ray-flowers about 12, fertile; the style very short. 

 Uisk-flowers about the same uumber, infertile ; their style-branclies destitute of stigmatic 

 lines, filiform, barbellate-hispid. Akeues of the ray sparsely villous, trigoual-turbinate with 

 a strong rib at each angle; the pappus of nunieroiLs unequal rigid capillary bristles, little 

 longer than the akene : those of the disk abortive, with pappus of very few (usually 2 ) bristles 

 which are somewhat chaffy-dilated at base. 



26. HETEROTHEOA. Involucre hemispherical or broadly campanulate, of narrow rather 

 rigid bracts. Receptacle alveolate. Ray- and disk-flowers numerous, both fertile. Style- 

 branches of the hermaphrodite flowers tipped with a lanceolate or sometimes (in the same 

 species ?) ovate-triangular appendage. Akeues of the ray thickish, often triangular, with no 

 pappus or an obsolete crown, rarely a bristle or two; of the disk compressed, sericeous- 

 hirsute, and with a double pappus : the inner of copious and long capiOary scabrous bristles, 

 outer of numerous short and stout bristles or setiform sijnamellte. 



* * * * Pappus multisetose and double, both in disk and (when present) in the ray; the 

 inner capillary; outer very short and setulose or sciuamellate. 



27. CHRYSOPSIS. Heads many-flowered, with rays numerous, or rarely wanting. In- 

 volucre campanulate or hemispherical, of narrow regularly imbricated bracts, style- 

 appendages from linear-fUiform to slender-subulate. Akenes compressed, but often turgid, 

 from obovate to linear-fusiform. Principal pappus of numerous capUlary scabrous bristles ; 



