CARDUACEAE 1309 



ends of the branches. Invohicres bristly : bracts in several series, the inner narrower than 

 the outer, and tipped with pinnately branched spines. Receptacle flat, bristly. Flowers 

 perfect : corollas tubular, yellow. Anther tailed at the base. Stigmas unappendaged. 

 Achenes laterally attached, terete, striate. Pappus double, the outer series of naked 

 awns, the inner of shorter fimbriate scales. 



1. Cnicus benedictus L. Foliage hirsute or villous. Stems 1-4 dm. tall, branched : 

 leaf-blades papery, reticulated, irregularly spiny dentate or sinuate-pinnatifid, 5-15 cm. 

 long, those of the basal or lower stem-leaves narrowed into winged petioles, those of the 

 upper leaves sessile and partly clasping : involucres 4-5 cm. high ; bracts thin, ovate, 

 lanceolate or linear-lanceolate, each tipped with a spine with pectinately prickly margins : 

 receptacle densely beset with hair-like bristles : outer pappus-awns alternating with the 

 inner scales. 



In waste places, Nova Scotia to Georgia and Alabama. Spring and summer. Blessed Thistle. 



147. GOCHNATIA H.B.K. 



Shrubby plants, with more or less tomentose or glutinous foliage. Leaves alternate: 

 blades leathery, entire. Heads homogamous, few- many-flowered, cymose or paniculate. 

 Involucre of several dry or leathery imbricated bracts. Receptacle flat, naked. Corollas 

 essentially regular. Anthers sagittate at the base, the auricles tailed. Stigmas relatively 

 short, roundish obtuse or nearly truncate at the apex. Achenes oblong or nearly so, more 

 or less 5-ribbed, pubescent. Pappus copious, of rather rigid scabrous or barbellulate 

 bristles. 



1. Gochnatia hypoleuca (DC.) A. Gray. A rigid branching shrub 2-3 m. tall, 

 or a small tree, tlie branchlets pale or white-canescent. Leaf-blades oblong, elliptic or 

 oval, 1-3.5 cm. long, dark green and glabrous above, finely white-tomentose beneath, short- 

 petioled : heads in leafy-bracted panicles: involucres cylindric-campanulate, 5-6 mm., 

 high, 5-7-flowered ; bracts ovate to oblong-elliptic, acutish : flowers perfect : corollas white : 

 achenes 3 mm. long. 



On hillsides, southern Texas and adjacent Mexico. Throughout the year. 



148. THYRSANTHEMA Neck. 

 Perennial scapose herbs, with floccose-tomentose foliage. Leaves basal : blades flat 

 persistent pubescent beneath. Heads heterogamous, radiate, solitary and terminal, nod- 

 ding when young. Involucre many-flowered : bracts narrow, in few series, the inner suc- 

 cessively larger. Ray-flowers pistillate, fruit-producing : ligules about h as long as the 

 style, sometimes rose-purple. Disk-flowers perfect, wholly or partially neutral : corollas 

 white or purplish, more or less 2-lipped, the outer with 3 lobes to the lower lip, the inner 

 with 2 lobes. Achenes 5-nerved, columnar or fusiform. Pappus of numerous soft hair- 

 like bristles. \_Chaptalki Vent.] 



All achenes perfect, each with a beak as long as the body : leaf-blades lyrate or repand-lyrate. 



1. C. nutans. 

 Achenes of perfect flowers abortive, those of the pistillate flowers each narrowed 



into a neck : leaf-blades entire or remotely denticulate. 2. C. semiflosculare. 



1. Thyrsanthema nutans (L. ) Kuntze. Leaves basal ; blades oblanceolate or oblong- 

 oblanceolate, 5-15 cm. long, acute or apiculate, lyrate or repand-lyrate, thinly floccose or 

 glabrate above: scapes solitary or tufted, 1-5 dm. tall, simple: involucral bracts subulate 

 to narrowly linear, acuminate : achenes all perfect, pubescent, the beak as long as the 

 body. 



In open woods and on prairies, Texas and Mexico. 



2. Thyrsanthema semifloscul^re (Walt. ) Kuntze. Leaves basal : blades oblong to 

 oblanceolate, 4-10 cm. long, apiculate, entire or remotely denticulate, green and glabrous 

 above, densely white tomentose beneath : scapes 1-3 dm. tall, sometimes tufted, simple : 

 involucral bracts subulate to linear : ligules of the ray-flowers usually purple, broadly 

 linear, 7-10 mm. long : achenes of the pistillate flowers perfect, glabrous, 3 mm. long, 

 each constricted into a short neck. \_Chaptalia tomentosa Vent.] 



In moist pine lands, North Carolina to Florida and Texas. 



149. PEREZIA Lag. 

 Perennial caulescent herbs, often woolly near the base. Leaves alternate. Heads 

 homogamous, the flowers perfect and fruit-producing. Involucre few- or many-flowered: 



