CARDUACEAE 1287 



white ; lobes somewhat shorter than the throat : achenes obconic, 3.5—4 mm. long, appressed- 

 pubescent. 



On plains and prairies, Nebraska to Texas. Summer and fall. 



116. FLORESTINA Cass. 



Annual caulescent herbs. Leaves alternate : blades pinnately or pedately 3-7-parted 

 or entire towards the top of the stem. Heads discoid, numerous, corymbose. Involucres 

 turbinate-campanulate : bracts few, nearly equal, broadened upward. Receptacle flat, 

 naked. Ray-flowers wanting : disk-flowers perfect, fruit-producing : corollas white or 

 purplish. Anthers slightly sagittate at the base. Stigmas with pubescent attenuate-subu- 

 late appendages. Achenes narrow, nearly terete, 4-5-ribbed. Pappus of 8-10 hyaline 

 obtuse or retuse scales. 



1. Florestina tripteris DC. Foliage cinereous-pubescent. Stems 3-7 dm. tall, often 

 extensively branched, striate-ridged : leaf-blades various, those of the lower leaves entire, 

 ovate to oblong, 1-5 cm. long, those of the upper leaves almost pinnately compound, the 

 segments similar to the blades of the lower leaves but smaller : peduncles shorter than 

 the involucres : heads not showy : involucres 4-5 mm. high ; bracts linear to spatulate, dull 

 white at the tip, minutely pubescent : achenes enlarged upward, 3.5-4 mm. long, strigillose. 



On hillsides and prairies, Texas and adjacent Mexico. 



117. POLYPTERIS Nutt. 



Annual or perennial, usually pubescent caulescent herbs. Leaves mainly alternate or 

 opposite on the lower part of the stem : blades narrow, mostly entire. Heads discoid or 

 radiate, disposed in corymbs. Involucres campanulate to turbinate : bracts narrow, imbri- 

 cated in one or two series. Receptacle flat, naked. Ray-flowers pistillate, fruit-producing, 

 or wanting : ligules deeply colored. Disk-flowers perfect, fruit-producing : corollas col- 

 ored. Anthers entire or emarginate at the base. Stigmas elongated, glandular. Achenes 

 rather narrow, 4-angled. Pappus of 8-12 narrow ribbed scales, that of the outer achenes 

 more or less reduced. 



Perennial : bracts of the involucre scarious : corolla-throat campanulate. 1. P. integrifolia. 



Annual : bracts of the involucre mainly herbaceous : corolla-throat obsolete or nearly 

 so. 

 Heads homogamous : achenes much broadened upward, less than 4 mm. long. 



Involucres 10-12-flowered : achenes less than 5 mm. long. 2. P. caUosa. 



Involucres 20-30-flowered : achenes over 5 mm. long. 3. P. Texana, 



Heads heterogamous : achenes scarcely broadened upward, over 6 mm. long. 

 Bracts of the involucre about 1 cm. long at maturity : leaf-blades indistinctly 



3-nerved. 4. P. Hookeriana. 



Bracts of the involucre 1.5-2 cm. long at maturity : leaf-blades prominently 3- 



ribbed. 5. P. maxima. 



1. Polypteris integrifolia Nutt. Perennial, glabrous or sparingly pubescent. 

 Stems 5-15 dm. tall, corymbose above : leaf-blades linear or linear-lanceolate, 3-7 cm. 

 long, rather obtuse, entire, short-petioled : peduncles enlarged under the heads, often with 

 several scales: heads homogamous: involucral bracts oblong to spatulate, mostly 5-11 

 mm. long, mainly scarious and petalloid, obtuse: ray-flowers wanting: corollas white or 

 flesh-colored, achenes narrowly obpyramidal, about 4 mm. long, pubescent : pappus scales 

 linear-subulate, about as long as the achenes or longer. 



In dry pine lands, Georgia and Florida. Summer and fall. 



2. Polypteris callosa (Nutt.) A. Gray. Annual, pubescent. Stems 3-7 dm. tall, 

 often widely branched above : leaf-blades narrowly linear, 2-7 cm. long, acute, entire, ses- 

 sile or short-petioled : peduncles glandular-pubescent : heads homogamous : involucres 

 10-12-flowered : bracts linear or linear-oblong, 3-4 mm. long, strigillose, herbaceous : 

 achenes narrowly obpyramidal, 3.5-4 mm. long, commonly pubescent : pappus-scales sub- 

 orbicular or obovate, obtuse or retuse, the costae scarcely reaching the apex. 



In various situations, Missouri to Texas. Spring to fall. 



3. Polypteris Texina (DC. ) A. Gray. Annual, finely pubescent. Stems 2-6 dm. tall, 

 more or less branched: leaf-blades lanceolate, linear- lanceolate or linear-oblong, 2-8 cm. 

 long, entire, often undulate, acute or attenuate, manifestly petioled : peduncles glandular : 

 heads homogamous : involucres 20-30-flowered ; bracts linear or linear-oblanceolate : 

 achenes gradually narrowed to the base, 5.5-G mm. long. 



In dry or gravelly soil, Texas, New Mexico and adjacent Mexico. Spring and summer. 



4. Polypteris Hookeriana (T. & G. ) A. Gray. Annual, glandular-pubescent and 

 somewhat viscid. Stems 3-12 dm. tall, branched : leaf-blades lanceolate or linear-lanceo- 



