CARDUACEAE 1249 



lucres campanulate to hemispheric : bracts rather narrow, in 2-3 series. Receptacle con- 

 vex or conic, chaffy. Ray-flowers pistillate, fruit-producing : ligules yellow. Disk-flowers 

 perfect, fruit-producing, enveloped in the bractlets. Stigmas tipped by hirsute appendages. 

 Achenes 3-4-angled, truncate. Pappus a low crown, 2-4 teeth, or wanting. 



Foliage, especially the leaf-blades, smooth or very slightly scabrous. 



Heads usually over 1 cm. high : achenes glabrous. 1. H. helianthoides. 



Heads usually less than 1 cm. high : achenes pubescent above. 2. H. minor. 



Foliage, especially the leaf-blades, very scabrous. 3. H. scabra. 



1. Heliopsis helianthoides (L.)B.S.P. Stems 3-15 dm. tall, usually branched, 

 smooth and glabrous or nearly so. Leaf-blades thinnish, ovate to lanceolate, 8-20 cm. 

 long, sharply serrate, cuneate to truncate at the base : heads showy, with a rounded disk 

 usually over 1 cm. high : bracts of the involucre oblong-lanceolate to oblong, ciliate, acute 

 or acutish, the outer with spreading or reflexed tips : ray-flowers several ; ligules bright 

 yellow, 2-3 cm. long : bractlets dilated and erose at the apex : achenes glabrous, truncate 

 or obscurely 2-4-toothed at the apex. \_H. laevis Pers. ] 



In thickets or open woods, Ontario to Illinois, Florida and Alabama. Summer. 



2. Heliopsis minor (Hook.) C. Mohr. Stems 2-7 dm. tall, simple or sparingly 

 branched, smooth and glabrous. Leaf-blades thinnish, lanceolate, elliptic or oblong-lance- 

 olate, 3-10 cm. long, sharply serrate, cuneate, rounded or truncate at the base : heads with 

 disks usually less than 1 cm. high : bracts of the involucre lanceolate to oblong, rather ob- 

 tuse, the outer, at least, with spreading or reflexed tips : ray -flowers few ; ligules bright 

 yellow, 1-2 cm. long : achenes 2.5-3 mm. long: pappus short, [H. gracilis Nutt. ] 



In woods or on hillsides, Georgia and Florida to Arkansas. Summer and fall. 



3. Heliopsis scabra Dunal. Stems 8-12 dm. tall, simple or sparingly branched, 

 scabrous-hispidulous like the leaves. Leaf-blades thick, deltoid to ovate or broadly 

 lanceolate, 5-15 cm. long, serrate, cuneate to truncate at the base : heads showy, with 

 broadly conic disks : bracts of the involucres linear-oblong to oblong, acutish or obtuse : 

 ray-flowers several ; ligules 2-2.5 cm. long, bright yellow : bractlets slightly dilated and 

 barely erose at the tip : achenes pubescent on the margins, at least when young, each with 

 a pappus of 1-3 short awns, or a laciniate crown. 



In dry soil, Maine to British Columbia, New Jersey and Arkansas. Summer. 



80. TETRAGONOTHECA L. 



Perennial caulescent herbs, with pubescent foliage. Leaves opposite : blades coarsely 

 toothed or pinnatifid, sessile or connate-perfoliate. Heads radiate, showy. Involucres 

 broad, many-flowered : bracts various, the 4 outer foliaceous, the inner 6-15, small, each 

 subtending a ray -flower. Receptacle conic, chaffy. Ray-flowers pistillate, fruit-producing : 

 ligules yellow. Disk-flowers perfect, fruit-producing, enclosed in the bractlets. Stigmas 

 of the disk-flowers hispid, their appendages elongated. Achenes 4-angled or nearly 

 terete, truncate. Pappus of several short scales or wanting. 



Achenes nearly terete or obscurely 4-sided : pappus wanting. 1. T. hdianthoides. 

 Achenes manifestly 4-angled : pappus of several scales, or rarely obsolete. 



Leaf-blades saliently toothed. 2. T. Ludoviciana. 

 Leaf-blades pinnatifid or repand. 



Corolla-tube glabrous : leaf-blades mainly repand. 3. T. repanda. 



Corolla-tube pubescent : leaf-blades mainly pinnatifid. 4. T. Texana. 



1. Tetragonotheca helianthoides L. Stems commonly tufted, 3-10 dm. tall, hirsute 

 or somewhat villous. Leaf-blades oblong to oval, or sometimes broadest above the middle, 

 acute or acuminate, remotely but sharply toothed, ciliate, the upper ones partly clasping : 

 heads showy, long-peduncled : involucres 4-angled, the outer bracts ovate to ovate-lance- 

 olate, acute, ciliate, cordate, 2-3 cm. long : ray-flowers with yellow ligules 3-4 cm. long : 

 achenes turgid, nearly terete, or obscurely 4-sided, 5-6 mm. long, without pappus. 



In dry soil, Virginia to Florida and Alabama. Spring to fall. 



2. Tetragonotheca Ludoviciana (T. & G.) A. Gray. Stems 5-12 dm. tall, glabrous 

 or nearly so, more or less branched. Leaf -blades oblong, oval or ovate, 5-17 cm. long, 

 acute, closely and saliently-toothed, the lower with broad ,' bases, the upper sessile or 

 connate-perfoliate : heads rather showy : involucres scarcely angled : the outer bracts ovate 

 to orbicular, not cordate : ligules of the ray-flowers 1-2 cm. long : achenes manifestly 4- 

 angled, 5-6 mm. long, mostly with a crown-like pappus. 



In sandy soil, Louisiana and Texas. Spring and summer. 

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