CARDUACEAE 1239 



nate, tomentose beneath, sessile or the upper clasping : heads showy, on stout peduncles : 

 involucres 1-1.5 cm. long : bracts ovate to oblong or spatulate, acutish or obtuse, tomentose 

 without : ray-flowers numerous ; ligules narrowly linear, 2-3 cm. long : achenes 4-5 mm. 

 long. 



In waste places, Nova Scotia to Ontario and Minnesota, North Carolina and Missouri. Summer. 



68. POLYMNIA L. 



Perennial large caulescent herbs, or shrubby plants. Leaves opposite or mainly so : 

 blades membranous, toothed, angled or usually lobed, petioled. Head* usually radiate. 

 Involucres many-flowered, double, an outer of about 5 loose bracts and an inner of as many 

 or more thin bracts subtending but not embracing the adjacent achenes. Receptacle flat. 

 Ray-flowers with short pubescent tubes and white or yellow ligules which are sometimes 

 very small. Disk-flowers not fruit-producing, subtended by chaffy bractlets. Anthers 2- 

 toothed at the base. Achenes swollen, relatively short, glabrous. Pappus wanting. The 

 plants flower in summer and fall. LEAF-CUP. 



Leaf-blades palmately lobed or angled : ray-flowers with yellow ligules : achenes prominently etriate. 



1. P. Uvedalia. 

 Leaf -blades pinnately lobed : ray-flowers with white, often small, ligules : achenes 3- 



5-ribbed or angled. 

 Foliage manifestly or copiously pubescent : achenes 3-ribbed or angled. 



Ray-flowers conspicuous : ligules 5-10 mm. long. 2. P. radiata. 



Ray-flowers inconspicuous : ligules 1-2 mm. long. 3. P. Canadansit. 



Foliage glabrous or the stem with merely puberulent nodes : achenes 5-ribbed. 4. P. laevigata. 



1. Polymnia Uvedalia L. Stems 1-3 m. tall, commonly tufted, pubescent or nearly 

 gfabrous : leaf-blades 1-5 dm. in diameter, 3-5-lobed or angled, decurrent on the short 

 petioles, which are often fully as long as the blades : outer bracts of the involucre ovate to 

 elliptic, 9-14 cm. long, obtuse, mucronulate or notched, ciliate : ray -flowers 10-14 ; ligules 

 yellow, linear-oblong to elliptic, 1.5-2 cm. long : disk yellow : achenes obovoid, black, 

 5-6 mm. long, laterally flattened, prominently striate, bluntly apiculate. 



In moist soil or thickets, New York to Missouri, Florida and Texas. 



2. Polymnia radiata (A. Gray) Small. Stems 0.5-1.5 m. tall, viscid-pubescent, 

 somewhat branched : leaf -blades oblong to oval or oblong-ovate, 1.5-3 dm. long, acute or 

 acuminate, pinnately lobed : outer bracts of the involucre linear-lanceolate to lanceolate, 

 9-12 mm. long, acute or acuminate, glandular-pubescent and ciliate : ray-flowers few ; 

 ligules white, conspicuous, cuneate to oval-cuneate, 5-10 mm. long, 3-lobed : achenes 

 oblong-obovoid, nearly 5 mm. long, with 3 sharply margined angles. 



On damp hillsides, New York to Wisconsin, Georgia and Missouri. 



3. Polymnia Canadensis L. Stems branching, 0.5-1.5 m. tall, viscid-hirsute : leaf- 

 blades 1-2 dm. long, oblong, oval or ovate, mainly pinnately lobed, the lobes toothed or 

 sinuate : heads drooping : outer bracts of the involucres lanceolate, pubescent : ray-flowers 

 few ; ligules inconspicuous, whitish or greenish, suborbicular to orbicular-reniform, 1-2 

 mm. long or shorter, slightly 3-lobed : achenes obovoid, about 3 mm. long, obtusely 

 3-angled. 



In thickets and on damp hillsides, Ontario to Minnesota, Georgia and Missouri. 



4. Polymnia laevigata Beadle. Stems 0.5-1 m. tall, branching, glabrous or merely 

 puberulent at the nodes : leaf-blades thin, the lower ones oval, pinnately 5-7-lobed, the 

 lobes acuminate ; upper ones deltoid, laciniate-dentate or repand, all slender-petioled : 

 heads nodding : outer bracts of the involucre oblong-lanceolate : ray-flowers 3-5 : ligules 

 white, 2-3 mm. long, 3-lobed : disk light yellow : achenes 5-ribbed. 



On hillsides, Tennessee and Georgia. Summer. 



69. MBLAMPODIUM L. 



Annual or perennial small caulescent herbs, or shrubby plants. Leaves opposite : 

 blades often narrow, thickish, entire, toothed or pinnatifid. Heads radiate, sometimes 

 conspicuous. Involucre double, the outer of 4-5 partially united flat bracts, the inner of a 

 series of bracts, each embracing an achene and deciduous with it, but unarmed. Recep- 

 tacle convex or conic. Ray -flowers in 1 series, pistillate : ligules white or yellow. Disk- 

 flowers perfect but not fruit-producing. Anthers entire at the base. Achenes broadened 

 upward, somewhat incurved. Pappus wanting. The plants flower mainly in the spring 

 and summer. 



Leaf-blades entire: ray-flowers with ligules 8-10 mm. long. 1. M. cinereum. 



Leaf- blades pinnatifid : ray-flowers with ligules about 5 mm. long. 2. M. ramosissimum. 



