824 COMPOSITAE (COMPOSITE FAMILY) 



summit of the stem ; bracts tawny, the inner often marked with purple. 

 Sandy or gravelly soil, coast of s. Me. to Fla.; and from O. to Kan., and 

 southw. (Trop. Am.) 



31. tNULA L. ELECAMPANE 



Heads many-flowered, radiate ; disk-flowers perfect and fertile. Involucre 

 imbricated, hemispherical, the outer bracts herbaceous or leaf -like. Receptacle 

 naked. Anthers caudate. Achenes more or less 4-5-ribbed; pappus simple, 

 of capillary bristles. Coarse herbs, not floccose-woolly, with alternate simple 

 leaves, and large yellow heads. (The ancient Latin name.) 



1. I. HELENIUM L. (ELECAMPANE.) Stout perennial, 1-1.5 m. high ; leaves 

 large, woolly beneath ; those from the thick root ovate, petioled, trie others 

 partly clasping ; rays very many, narrow. Roadsides and damp pastures. Aug. 

 Heads very large. Root mucilaginous. (Nat. from Eu.) 



32. ADENOCAULON Hook. 



Heads 5-10-flowered ; the flowers all tubular and with similar corollas, the 

 marginal flowers pistillate, fertile ; the others perfect but sterile. Involucral 

 bracts equal, in 1 row. Receptacle flat, naked. Anthers caudate. Achenes 

 elongated at maturity, club-shaped, beset with stalked glands above ; pappus 

 none. Slender perennials, with alternate thin petioled leaves smooth and green 

 above, white-woolly beneath, and few small (whitish) heads in a loose panicle, 

 beset with glands (whence the name, from dd-^v, a gland, and Kav\6s, a stem}. 



1. A. bicolor Hook. Stem 3-9 dm. high ; leaves triangular, rather heart- 

 shaped, with angular-toothed margins; petioles margined. Moist woods, shores 

 of L. Huron, L. Superior, and westw. 



33. POLYMNIA L. LEAFCUP 



Heads broad, many-flowered ; rays several (rarely abortive), pistillate ; disk- 

 flowers perfect but sterile. Involucral bracts in two rows ; the outer large, 

 spreading; the inner membranaceous, partly embracing the thick achenes. 

 Receptacle flat, membranous-chaffy. Pappus none. Tall branching peren- 

 nials, viscid-hairy, exhaling a heavy odor. Leaves large, thin, opposite, or the 

 uppermost alternate, lobed, with dilated appendages at the base. Heads in 

 panicled corymbs. Flowers light yellow, in summer and autumn. (Dedicated 

 to the Muse, Polyhymnia, for no obvious reason.) 



1. P. canadensis L. Clammy-hairy, 0.5-1.5 in. high ; lower leaves deeply 

 pinnatifid, the uppermost triangular-ovate and 3-5-lobed or -angled, petioled ; 

 heads small ; rays 5, obovate or wedge-form, shorter than the involucre, usually 

 minute or abortive, whitish-yellow, but sometimes (var. RADI!TA Gray) more 

 developed, 3-lobed, 1 cm. long, and whitish; achenes 3-costate, not striate. 

 Moist shaded ravines, w. Vt. to Ont., Minn., southw. and south westw. 



2. P. uvedalia L. Eoughish-hairy, stout, 1-3 m. high ; leaves broadly ovate, 

 angled and toothed, nearly sessile ; the lower palmately lobed, abruptly nar- 

 rowed into a winged petiole ; outer involucral bracts very large ; rays 10-15, 

 linear-oblong, much longer' than the inner bracts of the involucre, yellow ; 

 achenes strongly striate. Rich soil, N. Y. to Mo., and southw. 



34. ACANTHOSPERMUM Schrank 



Heads small, axillary or subsessile in the forks of the stem. Ray-flowers few, 

 fertile ; the ligules small, yellow, usually 3-dentate ; the disk-flowers with cam- 

 panulate yellow 5-toothed corolla, sterile. Involucre double, the outer bracts 

 herbaceous, the inner more or less strongly modified, closely enveloping the 

 fertile ray-achenes, muricate or prickly. Diffuse annuals with opposite toothed 

 or lobed leaves. (Name from dicavBa, a thorn, and <nrtp/ji.a, seed, from the prickly 

 fruit formed by the achene and its investing bract.) 



