COMPOSITAE. 



[Vol. III. 



3. Thelesperma gracile (Torr.) A. Graj-. 

 Rayless Thelesperma. (Fig. 3953.) 



Bideiii gracilis Torr. Ann. Lye. N. Y. 2: 215. 1827. 

 Thelesperma gracile A. Gray, Kew Joum. Bot. i: 252. 



1S49. 



Perennial from a deep root; stem rigid, branched, 

 i°-3° high, the branches nearly erect. Leaves 

 rigid, erect or ascending, i'-^' long, pinnately or 

 bipinnately divided into linear segments, or the 

 upper linear and entire; heads 6"-to" broad; rays 

 usually none, sometimes present and 2"-3" long; 

 outer bracts of the involucre 4-6, oblong or ovate, 

 mostly obtuse, very much shorter than the inner 

 ones which are united to the middle or beyond; 

 disk yellow or brownish; outer achenes slightly 

 papillose; pappus-awns longer than the width of 

 the summit of the achene. 



On dry plains, Nebraska and Wyoming to Texas, 

 northern Mexico and .\rizona. May-Aug. 



69. GALINSOGA R. & P. Prodr. Fl. Per. no. //. ^-^. 1794. 

 .\nnual branching herbs, with opposite, mostly petioled, dentate or entire leaves, and 



small peduncled heads of both tubular and radiate flowers, terminal and in the upper axils. 

 Involucre hemispheric or broadly campanulate, its bracts in 2 series, ovate, obtuse, mem- 

 branous, striate, nearly equal, or the outer shorter. Receptacle conic or elongated, its thin 

 chaff subtending the disk-flowers. Ray-flowers white, pistillate, fertile, the rays 4 or 5. short. 

 Disk-flowers yellow, perfect, the corolla 5-toothed. Anthers minutely sagittate at the 

 base. Style-branches tipped with acute appendages. Achenes angled, or the outer ones flat. 

 Pappus of the disk-flowers of several short laciniatcor fimbriate scales, that of the ray-flow- 

 ers of several or few short slender bristles, or none. [Named in honor of JI. M. Galinsoga, 

 superintendent of the Botanic Gardens at Madrid] 



.About 5 species, natives of tropical and warm temperate .America. 



I. Galinsoga parviflora Cav. Galinsoga. (Fig. 3954.) 



Galinsoga par-'iflora Cav. Icon. 3: 41. pi. 2S1. 1794. i^ 



Slightly appressed-pubescent, i°-3° high. Leaves 

 thin, ovate or deltoid-ovate, 3-nerved, i'-3' long, acute 

 at the apex, mostly obtuse at the base, dentate, the 

 lower sleuder-petioled, the upper short-petioled or ses- 

 sile, and sometimes nearly or quite entire; heads usu- 

 ally numerous, 2"-3" broad, slender-peduncled; bracts 

 of the involucre glabrous or nearly so, the outer 

 shorter; pappus of the disk-flowers 4-H\ oblong to 

 spatulate, fimbriate obtusish scales, shorter than the 

 finely pubescent obpyramidal achene. 



In door-yards and waste places, eastern Massachusetts 

 to Oregon, North Carolina, Missouri and Mexico. Natu- 

 ralized from tropical .America. Introduced into Europe 

 as a weed. June-Nov. 



Galinsoga parviflora hispida DC. Prodr. 5: 677. 1S36. 



Pubescence more abundant, especially above, spreading; 

 pappus of the disk-flowers attenuate, bristle-tipped. In 

 waste places, Rhode Island to Pennsylvania, North Caro- 

 lina and Wisconsin. 



70. ACTINOSPERMUM Ell. Bot. S. C. & Ga. 2: 448. 1S24. 

 [B.\LDiiXA Nutt. Gen. 2: 175. 1818. Not Baldwiiiia Raf F. iSiS.] 



.Annual or perennial,simple or branched, erect herbs, with alternate entire narrow punctate 

 leaves, and large terminal heads of both tubular and radiate, yellow flowers, or those of the 

 disk purplish. Involucre hemispheric, its small bracts imbricated in several series, appressed, 

 or with spreading tips, the outer shorter. Receptacle convex, deeply honey-combed, chaffy, 

 the persistent chaff coriaceous or cartilaginous, laterally united, subtending the disk-flowers. 

 Rays large, neutral, toothed. Disk-flowers perfect, fertile, the corolla 5-toothed. .Anthers 

 sagittate at the base. St}'le-brauches with truncate subulate tips. .Achenes turbinate, silky- 

 villous. Pappusof 7-12 scarious nearly equal scales. [Greek ray-seed.] 



Two known species, natives of tba southeastern Inited States. 



