CAKDUACEAE 1185 



28. BRINTONIA Greene. 

 Perennial caulescent herbs with pubescent foliage. Leaves alternate : blades broad, 

 coarsely toothed or partially entire, with broad petiole-like bases. Heads discoid. Invo- 

 lucres campanulate, 10-20-flowered : bracts in several series. Keceptacle naked, pitted. 

 Corollas regular, with rather long lobes. Stigmas with lanceolate appendages. Achenes 

 ribbed. Pappus of rough hair-like bristles, the inner club-shaped at the apex. 



1. Briiitonia discoidea (Ell.) Greene. Steros finely hirsute with gray hairs, 8-15 

 dm. tall, often widely branched above. Leaf-blades oval, ovate or oblong-ovate, 4-9 cm. 

 long, acute or slightly acuminate, coarsely serrate or the upper ones entire, all rather ab- 

 ruptly narrowed into broad petiole-like bases : racemes open : heads rayless, yellowish white : 

 involucres 6-8 mm. high : corollas various, the outer with shorter lobes than the inner : 

 pappus-bristles with the club-shaped tips often purple-tinged. ISolidago discoidea (Ell. ) 

 T. &G.] 



In dry soil, Georgia and Florida to Louisiana. Summer and fall. 



29. PRIONOPSIS Nutt. 



Annual or biennial caulescent glabrous herbs. Leaves alternate : blades spinulose- 

 toothed, sessile. Heads radiate, showy. Involucres broadly hemispheric, many-flowered : 

 bracts in several series, the outer often slightly spreading, the inner successively longer. 

 Receptacle naked. Pay-flowers numerous, pistillate. Disk-flowers perfect. Corollas yel- 

 low. Anthers obtuse at the base. Stigmas with linear-lanceolate appendages. Achenes 

 glabrous, those of tlie ray stouter and broader than those of the disk. Pappus of few firm 

 hair-like bristles, the outer often shorter, all deciduous. 



1. Prionopsis cilia ta Nutt. Stems 8-15 dm. tall, sparingly branched. Leaves 

 numerous ; blades obovate to oblong or oval, 2-9 cm. long, acutish or rounded at the apex, 

 closely dentate-serrate, sessile : heads few, in contracted corymbs, showy : involucres hemi- 

 spheric, about 1 cm. high, 2-2.5 cm. broad ; bracts linear-lanceolate to linear, acuminate : 

 ray-flowers numerous; ligules yellow, 1-1.5 cm. long: achenes 2.5-3 mm. long. 



On river banks and hillsides, Missouri and Kansas to Texas. Summer and fall. 



30. SIDERANTHUS Eraser. 



Annual or perennial herbs or shrubs. Leaves alternate : blades flat, spinulose-toothed 



or lobed, or pinnatifid, commonly sessile. Heads radiate and showy or rarely discoid. 



Involucres hemispheric or campanulate, many-flowered : bracts in several series, the inner 



successively larger. Receptacle flat or nearly so, naked, generally pitted. Ray-flowers 



pistillate. Disk-flowers mostly perfect. Corollas yellow : tube scarcely dilated into a 



throat. Anthers obtuse at the base. Stigmas flattened, with lanceolate appendages. 



Achenes obtuse, pubescent, mostly 8-10-nerved. Pappus of 1-3 series of many unequal 



hair-like bristles, persistent. [Eriocarpum ^iitt.'} 



Plants ainiual or biennial. 



Bracts of the involucre acute or acuminate. 



Inner bracts of the involucre about 1.5 cm. long. 1. S. megacephalus. 



Inner bracts of the involucre 6-9 mm. long. 



Involucres terminating leafy branches : stem-leaves pinnatifid. 2. S. phyUocephalus. 



Involucres terminating naked peduncles : stem-leaves merely toothed. 3. S. rubiginosus. 

 Bracts of the involucre obtuse or rounded at the apex. 4. S. aui-eiis. 



Plants perennial, often woody at the base. 



Stem glabrous or merely minutely puberulent. 5. S. glaberrimus. 



Stem woolly or glandular. 

 Stem glandular-pubescent. 

 Leaf-blades bipinnatifid. 



Leaf-blades 1-2 cm. long, the segments mostly less than 1 mm. wide. 6. S. Cotula. 

 Leaf-blades 2..5-4.5 cm. long, the segments mostly over 1 mm. wide. 7. S. Machaer anther a. 

 Leaf-blades incised or merely pinnatifid. 8. S. ausfraJis. 



Stem woolly-canescent with white hairs. 9. S. spmulosus. 



1. Sideranthus megac6phalus (Nash) Small. Stems finely pubescent, 8-12 dm. 

 tall, much branched. Leaves numerous ; blades lanceolate to linear-oblong, 2-7 cm. Ion" 

 with distant spreading or recurved teeth, sessile : heads showy, on stout hirsute peduncles : 

 involucres about 1 cm. high ; bracts linear-lanceolate to linear, acute, ciliate : rav-flowers 

 with linear or oblong-linear ligules about 1 cm. long. [Eriocarpum megacephalum Nash.] 



In sandy soil, Florida and Texas. Summer and fall. 

 75 



