CARDUACEAE 



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. Brintonia discoidea (Ell.) Greene. Stems 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. [Solidago discoidea (Ell.) 



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



29. FRIONOFSIS 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. Ray-flowers numerous, pistillate. Disk-flowers perfect. Corollas yel- 

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

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

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



1. Frionopsis ciliata 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 Nutt. ] 



Plants annual or biennial. 



Bracts of the involucre acute or acuminate. 



Inner bracts of the involucre about 1.5cm. 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. aureus. 



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. 

 Leaf-blades 2.5-4.5 cm. long, the segments mostly over 1 mm. wide. 

 Leaf-blades incised or merely pinnatifid. 

 Stem woolly-canescent with white hairs. 



6. 5. Cotula. 



7. S. Machaera nthera. 



8. S. australis. 



9. S. spinulosus. 



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

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

 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 : ray-flowers 

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



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

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