CICHOKIACEAE 1319 



to ovate-lanceolate, 4-5 mm. long, becoming keeled, firm: achenes barely 1.5 mm. long, 

 ribbed and transversely wrinkled : pappus-scales broadly obovate, the bristles alternating 

 with those over the stronger ribs about as long as the pappus-scales or wanting. 

 On prairies, Missouri to Arkansas and Texas. Spring. 



2. Adopogon Carolinianus (Walt.) Britton. Annual, often pubescent, glauces- 

 cent. Leaf-blades spatulate or nearly linear in outline, 2-12 cm. long, coarsely toothed, 

 deeply pinnatifid : scapes erect or ascending, 3-40 cm. tall, usually glandular-hirsute under 

 the head : involucres glabrous ; bracts 9-18, linear to lanceolate, 4-5 mm. long, thin, nerve- 

 less : achenes 1.5 mm. long, 5-angled, narrowly turbinate : pappus-bristles about twice as 

 long as the achenes and many times longer than the rounded obovate scales. [Krigia 

 Virginica Willd.] 



In dry soil, Maine to Ontario and Minnesota, south to Florida and Texas. Spring and summer. 



3. Adopogon Virginians (L. ) Kuntze. Perennial, glabrous or nearly so. Stems 

 erect, 1-7 dm. tall, simple or branched, sometimes scape-like : leaf-blades spatulate, ob- 

 long or oval, 5-20 cm. long, obtuse or acute, entire, repand or somewhat lyrate, often nar- 

 rowed into broadly-winged petioles ; stem-leaves with small sessile partly clasping 

 blades : peduncles sometimes glandular-hirsute under the heads : involucres glabrous ; 

 bracts linear or linear-lanceolate: heads 1-1.5 cm. long, orange to reddish orange : 

 achenes 2 mm. long, nearly oblong : pappus 10-15 small oblong scales and as many or 

 more bristles longer than the achene. [Krigia amplexicaulis Nutt.j 



In meadows and moist open woods, Massachusetts to Ontario, Manitoba, Georgia, and Kansas. 

 Spring to fall. 



4. Adopogon montanus (Michx. ) Kuntze. Perennial, glabrous or nearly so. 

 Stems erect or decumbent, more or less branched : leaves often numerous ; blades linear or 

 linear-spatulate, elongated, 8-20 cm. long, entire or pinnatifid ; segments acute or narrow : 

 scapes few or numerous, 1-3 dm. long, sometimes glandular-hirsute under the head : invo- 

 lucres glabrous ; bracts linear to linear-lanceolate or oblong-lanceolate, 8-10 mm. long : 

 heads bright yellow, 2.5-3 cm. broad : achenes 2.5-3 mm. long, finely ribbed : pappus- 

 bristles barely 'twice as long as the achene. [Krigia montana (Michx.) Iraki* ] 



On cliffs, on the Blue Ridge, North Carolina to Georgia. Summer and fall. 



5. Adopogon Dandelion (L. ) Kuntze, Perennial, producing tubers. Stems want- 

 ing or very short : leaves usually clustered ; blades spatulate to linear-oblong or linear, 5- 

 15 cm. long, acute, undulate, denticulate or pinnatifid, the segments acute or narrow : 

 scapes erect or ascending, 0.5-5 dm. tall, often glandular-hirsute under the head : invo- 

 lucres glabrous ; bracts linear or narrowly linear-lanceolate : heads yellow, 2.5-3 cm. 

 broad : achenes slightly over 2 mm. long, glandular-ribbed : pappus-bristles twice as long 

 as the achene. [Krigia Dandelion (L. ) Nutt] 



In moist soil, Maryland to Kansas, Florida and Texas. Spring and summer. 



11. SERINEA Raf. 



Annual herbs, with low branching stems. Leaves sometimes apparently opposite : 

 blades entire or pinnatifid, some or all of them clasping. Heads small, commonly broadly 

 so : bracts often 8, membranous, all similar, concave at maturity. Receptacle flat, naked. 

 Flowers few ; ligules yellow or orange, truncate and toothed at the apex. Anthers sagit- 

 tate at the base. Stigmas slender. Achenes broadest above the middle, 8-10-ribbed. 

 Pappus wanting or obsolete. [Apogon Ell. ] 



Corollas pure yellow, slightly surpassing the involucre : heads less than 5 mm. high at maturity. 



1. S. oppositifolia, 

 Corollas orange, about twice the length of the involucres : heads over 5 mm. high 



at maturity. 



Achenes about 1 mm. long. 2. S. gracilis. 



Achenes about 1.5 mm. long. 3. S. Wrightii. 



1. Serinea oppositifolia (Raf.) Kuntze. Foliage glabrous, or glandular on the pe- 

 duncles under the head. Stems commonly branched at the base ; branches erect or spread- 

 ing, 0.5-3 dm. long, usually weak : leaf -blades various, spatulate to linear, 2-12 cm. long, 

 entire or sinuate-pinnatifid, conspicuously irregular : involucres 4 mm. high at maturity ; 

 bracts linear-lanceolate to ovate, acute : heads pure yellow : corollas slightly surpassing 

 the involucres : achenes oblong-obovate, 1.5 mm. long, ribbed and minutely wrinkled : 

 pappus wanting, f Apogon humilis Ell.] 



In sandy soil and fields, South Carolina to Kansas, Florida and Texas. Spring. 



2. Serinea gracilis (DC.) Kuntze. Foliage glabrous to the more or less copi- 

 ously glandular-pubescent peduncles. Stems branched at the base ; branches ascending or 



