Family: Asteraceae |
Biennials, perennials, or subshrubs, 20-110(-150) cm, hairs usually soft, flexible, flagelliform (1-5 large, short basal cells, abruptly changing to thinner, elongate distal cells); taprooted or fibrous-rooted. Stems erect, ascending, procumbent or decumbent, simple or branched, glabrous or woolly, arachnoid (in C. mariana), often densely stipitate-glandular, especially distally. Leaves: basal (in rosettes) and cauline; alternate; sessile; basal blades 1-nerved (net-veined), spatulate to oblanceolate (bases petiole-like), margins entire or apically dentate-serrate, faces usually sparsely to densely woolly (at least in young rosettes) or piloso-sericeous, rarely arachnoid; cauline blades linear, lanceolate, elliptic, or ovate (bases sometimes ± clasping), margins entire or dentate, sometimes coarsely ciliate, faces glabrous or densely woolly, pilose, or arachnoid, or stipitate-glandular. Heads in corymbiform, subumbelliform, or paniculiform arrays (peduncles nearly naked to leafy-bracteate). Involucres campanulate, (5-12 ×) 5.5-14 mm. Phyllaries 30-55 in 3-5 series, 1-nerved, (weakly to strongly keeled proximally, flat to slightly convex distally), linear-lanceolate to oblanceolate, unequal, chartaceous to membranous proximally, membranous or foliaceous distally, margins scarious proximally, faces glabrous or hairy, sometimes stipitate-glandular or gland-dotted. Receptacles slightly convex, shallowly pitted, epaleate. Ray florets 9-36, pistillate, fertile; corollas yellow. Disc florets 25-90, bisexual, fertile; corollas yellow, ampliate, tubes ± equaling distally dilated throats, lobes 5, erect, triangular; style-branch appendages triangular. Cypselae (stramineous) obconic, compressed, usually smooth or shallowly 1-10-ribbed, sometimes 2-10-ridged (ridges yellow to red-brown, clavate, translucent), faces sparsely to moderately strigose; pappi persistent, in (2-)3(-4) series, outer of linear to narrowly triangular scales 0.4-1.4 mm, inner 1-2(-3) series of 20-40 whitish to stramineous, thin, barbellate, apically attenuate or clavate bristles. x = 5, 4, 9. All species of Chrysopsis are native to Florida; two species occur also north and west of the state. As circumscribed here, the genus includes the North American goldenasters that bear flagelliform hairs with bases of large cells. Historically, Chrysopsis included most species treated here in Heterotheca and all species treated here in Pityopsis (J. C. Semple 1981, 1996, literature cited therein). The two annual species of Bradburia are excluded, although G. L. Nesom (1991) included them in Chrysopsis. The cytotaxonomy of Chrysopsis has been studied in detail with the karyotypes of nearly all species illustrated, the allopolypoid origins of the C. gossypina complex documented, and the cytogeography of the four ploidy levels in C. mariana described (Semple 1977; Semple et al. 1980; Semple and C. C. Chinnappa 1980, 1980b, 1984, 1986). Semple and J. L. A. Hood (2005) described the pappi of the genera of subtribe Chrysopsidinae. Pappus traits of species within Chrysopsis are similar but differ from those of Bradburia, Heterotheca, and Pityopsis. Most species of Chrysopsis are restricted to limited habitats within Florida; some are rare or threatened. Different morphotypes of C. gossypina, a variable allopolyploid, may be superficially similar to one or another of the distinct diploid species (Semple 1981). Diplogon Rafinesque is a rejected name.
Heads radiate (in ours), the rays yellow, pistillate and fertile; invol bracts imbricate, greenish at least in part; receptacle flat or a little convex, naked; disk-fls numerous, perfect and fertile; style-branches flattened, with externally short- hairy, mostly elongate appendage; achenes ±compressed, several- to many-nerved; pappus double, the inner of elongate capillary bristles, the outer of short, coarse bristles or scales; herbs with alternate, entire or inconspicuously toothed lvs and medium-sized or rather large heads. 20, N. Amer. (Pityopsis) Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp. ©The New York Botanical Garden. All rights reserved. Used by permission. |