37- 



COMPOSITAE. 



Vol. III. 



13. HETEROTHECA Cass. Diet. Sri. Nat. 21: 130. 1821. 



Erect, hirsute or pubescent, branching herbs, with alternate, mostly dentate leaves, and 

 rather large heads of both discoid and radiate yellow (lowers, generally solitary at the ends 

 of the branches. Involucre hemispheric or broadly campanulate, its bracts imbricated in 

 several series, the outer shorter. Receptacle flat, alveolate. Kay-flowers pistillate. Disk- 

 flowers perfect, or some of them only staminate. Style-branches flat, their appendages 

 lanceolate or triangular. Achenes pubescent, obtuse, those of the ray-flowers thick, those 

 of the disk-flowers flattened. Pappus of the ray-flowers obsolete or of a few caducous bristles, 

 that of the disk-flowers of an inner row of numerous capillary rough bristles, and an outer 

 row of shorter stouter bristles or scales. [Greek, different-case, from the dissimilar achenes.] 



Five or 6 species, natives of the southern United States and Mexico, the following typical. 



i. Heterotheca subaxillaris ( Lam.) Britton & Rusby. Heterotheca. Fig. 4194. 



Inula subaxillaris Lam. Encycl. 3: 259. 1799. 



Heterotheca Lamarckii Cass. Diet. Sci. Nat. ax: 131. 

 iSji. 



Heterotheca subaxillaris Britton & Rusby, Trans. N. Y. 

 Acad. Sci. 7 : 10. 1887. 



Biennial or sometimes annual, l-3 high. Basal 

 and lower leaves petioled, ovate or oblong, 2' -J,' 

 long, the upper ones oblong, sessile or clasping, 

 smaller, all acutish or obtuse, dentate ; heads rather 

 numerous, 6"-g" broad ; involucre nearly hemispheric, 

 3"s" high, its bracts linear, or slightly dilated above, 

 the inner with scarious margins ; rays 10-25 ; inner 

 bristles of the pappus of the disk-flowers about 2" 

 long. 



In dry soil, Delaware to Florida, Louisiana, Kansas. 

 Arizona and Mexico. In ballast, at Philadelphia. July- 

 Sept. 



14. CHRYSOPSIS [Ntttt.] Ell. Bot. S. C. & Ga. 2: 333. 1824. 

 [Diplogon Raf. Amer. Month. Mag. 2: 268. 1818. Not Poiret, 1811.] 

 Perennial or biennial, rarely annual, branching herbs, with alternate sessile entire leaves, 

 or the basal ones dentate, and large many-flowered heads of both tubular and radiate yellow 

 flowers (rays wanting in some western species), loosely corymbose, or solitary at the ends 

 of the branches. Involucre campanulate to hemispheric, its bracts narrow, imbricated in 

 several series, the outer shorter. Receptacle usually flat, more or less foveolate. Ray-flowers 

 pistillate. Disk-flowers mostly all perfect. Pappus double in both the disk- and ray-flowers, 

 the inner of numerous rough capillary bristles, the outer of smaller or minute scales or 

 bristles. Achenes flattened, oblong-linear or obovate, pubescent. Style-branches narrow, 

 somewhat flattened, their appendages linear or subulate. [Greek, of golden aspect.l 



About 20 species, natives of North America and Mexico. Besides the following, about 8 others 

 occur in the southern and western United States. Type species: Ckrysopsis gossypina (Michx.) Ell. 



Leaves elongated-linear, entire, parallel-veined ; achenes linear ; involucre campanulate. 



Plants i-3 high, silvery-pubescent; leaves grass-like, 3'-'-' long. 1. C. graminifolia. 



Plants 4'-io' high, woolly-pubescent ; leaves rigid, 1' 4' long. 2. C. falcata. 



Leaves oblong, lanceolate, or linear, pinnately veined ; achenes obovate, or oval ; involucre hemi- 

 spheric. 

 Plant densely woolly-pubescent. 3- G. gossypina. 



Plants hirsute, or villous-pubescent. 



Heads numerous, corymbose-paniculate ; pubescence of long deciduous hairs ; eastern species. 



4. C. niariana. 

 Heads fewer, corymbose, or terminating the branches ; pubescence persistent ; western species. 

 Villous-pubescent. hirsute or hispid ; perennials. 



Villous-pubesct-nt and canescent with appressed hairs. 5. C. villosa. 



Hirsute or hispid-pubescent. 



Leaves linear, acutish. 6. C. stenophylla. 



Leaves mostly spatulate, obtuse. 7. C. hispida. 



Pilose-pubescent with soft spreading hairs ; annual. 8. C. pilosa. 



