1250 CAKDUACEAE 



3. Tetragonotheca repanda (Buckl.) Small. Stems 3-5 dm. tall, minutely pubes- 

 cent, sparingly, branched if at all : leaf-blades ovate to ovate-lanceolate or rarely narrow 

 toward the top of the stem or spatulate near the base of the stem, mostly acute, repand, 

 narrowed into slender petiole-like bases : heads slender-peduncled, showy : involucres about 

 2 cm. broad, the outer bracts ovate to triangular-ovate or broader, partially united, the 

 lobes merely acute : ray-flowers with ligules 2-2.5 cm. long : achenes about 2 mm. long, 4- 

 angled, minutely pubescent. [Halea repanda Buckl.] 



In dry soil, southern Texas. Spring to fall. 



4. Tetragonotheca Texana ( A. Gray) Gray & Engelm. Stems solitary or tufted, 

 3-7 dm. tall, finely pubescent or glabrate. Leaf-blades oblong, elliptic or oval in outline, 

 pinnatifid, incised or repand, 3-10 cm. long, the lower withcuneate bases, the upper sessile 

 and connate-perfoliate by a toothed disk : heads showy, on elongated peduncles : involucres 

 2-2.5 cm. broad ; the outer bracts ovate, at least 1 cm. long, united below the middle, the 

 lobes acute or slightly acuminate : ray-flowers with ligules about 1 cm. long : achenes 4- 

 angled, obpyramidal, 3 mm. long, pubescent. 



In rocky soil, Texas and adjacent.Mexico. Spring to fall. 



81. ECLIPTA L. 



Annual caulescent herbs. Leaves opposite : blades narrow, entire or somewhat 

 toothed. Head radiate but inconspicuous, short-peduncled. Involucres hemispheric or 

 campanulate : bracta in about 2 series, the outer sometimes longer than the inner. Recep- 

 tacle flat or convex, chaffy. Ray-flowers pistillate, fruit-producing : ligules small, white. 

 Disk-flowers perfect, chiefly fruit-producing. Bractlets awn-like. Stigmas of the disk- 

 flowers with obtuse or triangular tips. Achenes various : those of the ray 3-angled : those 

 of the disk flattened. Pappus of several short teeth, or wanting. 



Eclipta alba ( L. ) Hassk. Stems erect or procumbent, 2-9 dm. long, finely pubes- 

 cent, somewhat fleshy. Leaf-blades elliptic, oblong or lanceolate, sometimes nearly linear, 

 3-10 cm. long, acute or somewhat acuminate, remotely toothed or undulate, sessile : heads 

 inconspicuous : involucres broadly campanulate ; bracts united to about the middle, the 

 lobes ovate, acute, ciliolate : ray-flowers with white or nearly white ligules : achenes 

 cuneate, 2.5 mm. long, rugose, often truncate at maturity. 



In wet places, New York to Nebraska, Florida, and tropical America. Summer and fall. 



82. SCLEROCARPUS Jacq. 



Annual or perennial caulescent herbs with pubescent foliage. Leaves alternate or 

 opposite : blades often toothed. Heads radiate, peduncled. Involucres campanulate or 

 hemispheric : bracts distinct, in several series, the outer ones loose and spreading. Recep- 

 tacle convex or conic, chaffy. Ray-flowers several, neutral : ligules relatively broad. 

 Disk-flowers perfect, fruit-producing, permanently enveloped in the accrescent bractlets 

 "which fall away with the achene. Stigmas usually subulate-appendaged. Achenes smooth. 

 Pappus a low crown, or wanting. 



Ijigules of the ray-flowers 6-12 mm. long : achenes 3-4 mm. long. 1. S. unisenalis. 



lagules of the ray-flowers 17-28 mm. long : achenes 5-6 mm. long. 2. S. major. 



1. Sclerocarpus uniserialis (Hook.) B. & H. Annual, strigose-hispid. Stems 2-6 

 dm. tall, usually simple : leaves alternate ; blades 1.5-5 cm. long, deltoid or rhombic- 

 ovate, or the upper ones lanceolate, acute or acuminate, coarsely serrate-dentate, cuneate or 

 nearly truncate at the base : heads showy, long-peduncled : involucres lax ; bracts 6-8 

 mm. long: ray-flowers 5-8 ; ligules yellow, 6-12 mm. long, orbicular to oval; bractlets of 

 the disk becoming cartilaginous or bony, nearly terete, tuberculate-roughened : achenes 

 3-4 mm. long. 



In moist soil, Texas and adjacent Mexico. 



2. Sclerocarpus major Small. Similar to S. uniserialis in habit, but larger through- 

 out. Leaf-blades mainly 6-9 cm. long and somewhat acuminate, commonly broadly cuneate 

 at the base, long-petioled : bracts of the involucre 9-11 mm. long : ray-flowers with oblong 

 or ovate ligules 17-28 mm. long: achenes 5-6 mm. long. 



In rich soil, southern Texas and adjacent Mexico. 



83. MELANTHERA Rohr. 



Perennial caulescent herbs, with scabrous or pubescent foliage. Leaves opposite : 

 blades entire, toothed or hastately lobed, petioled. Heads discoid, rather inconspicuous, 



