In moist usually calcareous places, in marshes along streams and along irriga- 

 tion ditches in Okla. (Waterfall), in n.-cen. and e. Tex. and the Edwards Plateau 

 and Plains Country, N. M. (Sierra, Taos, Chaves, Otero and San Miguel cos.) 

 and Ariz. (Navajo, Yavapai and Cochise cos.), (Aug.-) Sept.-Oct.; widespread 

 in temp. N.A. 



7. Helenium arizonicum Blake. Fig. 775. 



Root biennial, vertical, slenderly conic, about 10 cm. long, 1 cm. thick above, 

 with few strong rootlets; stem solitary, erect, stout, striate-angled and sulcate, 

 greenish-white, erect-branched essentially from base to apex, obscurely incurved- 

 puberulous below, nearly glabrous above, dotted with yellow-brown glands; lower 

 leaves 8-10 cm. long (including petiole, this about 2 cm. long, narrowly 

 margined, at base ampliate, purplish and about 7-nerved), 6-10 mm. wide, 

 triplinerved, essentially glabrous, densely glandular-punctate on both sides, pale 

 green; stem leaves numerous, semiamplexicaul and decurrent for 1-4 mm., the 

 upperrnost .smaller; peduncles solitary at tips of stem and branches, enlarged just 

 below the head, many-sulcate, 2-1 1 cm. long; involucre soon reflexed; phyllaries 

 about 14, narrowly triangular, acuminate, 7-9 mm. long, 1-1.5 mm. wide at base, 

 sparsely pilose below, densely so toward tip, punctate; disk subglobose, 12-17 mm. 

 high, 15-20 mm. thick; submature receptacle 5 mm. long, 3 mm. thick; rays about 

 12 or more, cuneate, deeply 3-lobed (lobes blunt, 2.5-3.3 mm. long), 9- to 

 11-nerved, 12-13 mm. long, 6-7 mm. wide, densely gland-dotted outside; disk 

 corollas yellow, tipped with purple-brown, short-pilose on teeth with several-celled 

 hairs, 3.4 mm. long; disk achenes erect-pilose on the ribs with rufescent hairs, 

 sessile-glandular between the ribs, 2 mm. long; pappus scales 6 or 7, subequal, 

 1.8-2.3 mm. long, the body lanceolate or lance-ovate, gradually narrowed into the 

 awn. 



In wet meadows and on edge of ponds, in Ariz. (Coconino Co.), Aug.-Sept.; 

 endemic. 



38. Clappia Gray 



A monotypic genus. 

 1. Clappia suaedaefolia Gray. 



Subshrub from taproots, only slightly woody below, much-branched, the upper 

 third or fourth of the height being nearly naked fistulose peduncles; leaves opposite 

 on the lowest part of the stem but mostly alternate, crowded, confined to the lower 

 two thirds or three fourths of the plant, fleshy and almost terete, linear, rarely 

 with a lateral lobe or trifid in the distal half, often having lines of black (glan- 

 dular?) dots visible under a lens, grayish-green when fresh; heads solitary, on 

 the ends of the enlarged peduncles; involucre hemispheric, 8-10 mm. high; 

 phyllaries in about 4 or 5 series, strongly graduate, linear-oblong, definitely 

 rounded apically, rather firm-membranous with an exceedingly narrow scarious 

 margin, often with parallel dark or subglandular longitudinal striae; receptacle 

 convex, decidedly fimbriate-setose around the sockets but not chaffy; ray flowers 

 about 12, pistillate, fertile; rays yellow, linear, terminally 2- or 3-toothed; disk 

 flowers numerous, perfect, fertile, the corolla yellow and 5-toothed; style-branches 

 hispidulous, with ovate tips; achenes about 3.5 mm. long, columnar or slightly 

 tapered to the base, black, about 10-ribbed, the ribs hispidulous; pappus of 15 to 

 25 unequal coarse stiff slightly tawny dorsiventrally flattened persistent bristles 

 about as long as the achene. 



Locally abundant in subsaline or alkaline poorly drained clay flats, Rio Grande 

 Plains, spring-fall, less commonly summer and winter; also N.L. and Tam. 



1681 



