1286 CAKDUACEAE 



achenes 3-3.5 mm. long, hispidulous : pappus sordid, the bristles much longer than the 

 achene. 



In sandy soil, southern Texas and New Mexico. Summer. 



115. HYMENOPAFPUS L'Her. 



Biennial or perennial caulescent herbs, sometimes with woolly foliage. Leaves alter- 

 nate, sometimes mainly basal : blades pinnatifid or dissected or rarely entire. Heads dis- 

 coid, often corymbose. Involucres campanulate or hemispheric : bracts more or less petal- 

 like, 6-12 in 1-2 series. Receptacle small, naked. Ray-flowers wanting. Disk-flowers 

 perfect, fruit-producing : corollas white or yellow. Anthers entire at the base. Stigmas 

 with conic appendages. Achenes broadened upward, 4-5-angled, the faces 1-3-nerved. 

 Pappus of 10-20 thin obtuse scales, or sometimes obsolete. 



Corolla-lobes as long as the throat. 



Pappus-scales much shorter than the breadth of the top of the achene. 



Bracts of the involucre bright white : achenes pubescent. 1. H. Carolincnsit. 



Bracts of the involucre whitish or sulphur-yellow at the top : achenes pu- 



berulent. 



Leaf-segments, at least those of the lower leaves, oblong or broadly linear. 2. //. corymbosut. 

 Leaf-segments narrowly linear. 3. H. tulphureus. 



Pappus-scales about as long as the breadth of the top of the achene. 4. H. arttmifiatfoliut. 



Corolla-lobes shorter than the throat. 



Foliage densely tomentose : corollas yellow ; throat slightly longer than the 



lobes. 5. H. flavescens. 



Foliage thinly tomentose : corollas dull white ; throat much longer than the 



lobes. 6. H. tcnuifolius. 



1. Hymenopappus Carolinensis (Lam.) Porter. Foliage thinly tomentose. Stems 

 3-7 dm. tall, corymbose above : leaf-blades once or twice pinnately parted, or those at the 

 base of the stem rarely entire : involucral bracts oblong to obovate, thin, mostly bright 

 white : corolla-lobes about as long as the throat : achenes 2.5-3 mm. long, obconic, ribbed, 

 minutely pubescent : pappus-scales obovate, much shorter than the breadth of the top of 

 the achene. [H. scabiosus L'Her.] 



In dry soil or pine lands, South Carolina and Kansas to Florida and Texas. Spring. 



2. Hymenopappua coiymbosus T. & G. Foliage sparsely pubescent. Stems 2-7 

 dm. tall, corymbose above : leaf-blades once or twice pinnately parted, the segments nar- 

 rowly linear : involucral bracts oblong-obovate or obovate, the tips greenish white : corolla- 

 lobes as long as the throat or longer : achenes obconic, 3 mm. long, puberulent, finely 

 ribbed : pappus-scales shorter than the breadth of the top of the achene. 



On prairies, Nebraska to Arkansas and Texas. Spring and summer. 



3. Hymenopappus aulphureus Rydb. Foliage more or less permanently white- 

 woolly. Stems 3-6 dm. tall, branched above : leaf -blades white-woolly beneath, glabrate 

 above, those of the lower leaves pinnately divided into oblong or broadly linear often ob- 

 tuse segments, those of the upper leaves twice pinnately divided into narrower segments 

 than the lower : involucral bracts mainly obovate, the tips light or pale sulphur yellow, 

 otherwise as in H. corymbosus. 



On prairies, Kansas to Texas. Summer. 



4. Hymenopappus artemisiaefolius DC. Foliage felty or floccose-tomentose. 

 Stems 2-8 dm. tall, corymbose above : leaf-blades various, oblong to lanceolate in outline, 

 undulate, pinnatifid, sometimes lyrately so, or pinnately parted, the segments broadly 

 linear or narrowly oblong, toothed 'or lobed : involucral bracts obovate-oblong, white or 

 the lower pale green : corolla-lobes about as long as the throat : achenes about 3 mm. long, 

 hirsute : pappus-scales obovate-spatulate, about as long as the breadth of the top of the 

 achene. 



On plains or prairies, Texas. Spring. 



5. Hymenopappus flavescens A. Gray. Foliage densely white-tomentose. Stems 

 2-6 dm. tall, corymbose above ; leaf-blades once, twice or rarely thrice pinnately parted ; 

 the segments narrowly to broadly linear : involucral bracts ovate to oblong-ovate, with 

 greenish white or yellowish margins : corolla-lobes about as long as the campanulate 

 throat : achenes 2.5-3 mm. long, villous-pilose : pappus-scales spatulate. 



On sandy plains, Texas to Arizona and adjacent Mexico. Spring and summer. 



6. Hymenopappus tenuifolius Pursh. Foliage thickly tomentose. Stems 3-7 

 dm. tall, corymbose above : leaf-blades 2-10 cm. long, once or twice pinnately parted, 

 or those at the base of the stem thrice pinnately parted, the segments narrowly linear or 

 linear-filiform : involucres hemispheric, 5 mm. high ; bracts oblong-obovate : corollas dull 



