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. Receptacle 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: 
eos inde with the club-shaped tips often purple-tinged. [Solidago discoidea ( Ell.) 
DIC. sg 
In dry soil, Georgia and Florida to Louisiana. Summer and fall. 
29. PRIONÓPSIS 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. Prionopsis 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 em. high, 2-2.5 em. 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 billsides, Missouri and Kansas to Texas. Summer and fall. 
30. SIDERÁNTHUS Fraser. 
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. [Hriocarpum Nutt. ] 
Plants annual or biennial. 
Bracts of the involucre acute or acuminate. 
Inner bracts of the involucre about 1.5 em. long. 1. S. megacephalus. 
Inner braets of the involucre 6-9 mm. long. 
Involucres terminating leafy branches: stem-leaves pinnatifid. 2. S. phyllocephalus. 
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. f 
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 em. long, the segments mostly over 1 mm. wide. 7. S. Machaera nthera. 
Leaf-blades incised or merely pinnatifid. 8. S. australis. 
Stem woolly-canescent with white hairs. 9. S. spinulosus. . 
1. Sideranthus megacéphalus (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 em. long. [Eriocarpum megacephalum Nash.] 5 
In sandy soil, Florida and Texas. Summer and fall. 
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