Home at last: the enigmatic genera Eriachaenium and Adenocaulon (Compositae, Mutisioideae, Mutisieae, Adenocaulinae) Author Funk, Vicki A. Department of Botany, NMNH, Smithsonian Institution, Washington D. C., USA Author Pasini, Eduardo Department of Botany, NMNH, Smithsonian Institution, Washington D. C., USA & Universidade Federal do Rio Grande do Sul, Programa de Pos-Graduacao em Botanica, Av. Bento Goncalves 9500, CEP 91501 - 970, Porto Alegre, RS, Brazil Author Bonifacino, J. Mauricio Department of Botany, NMNH, Smithsonian Institution, Washington D. C., USA & Laboratorio de Botanica, Facultad de Agronomia, Universidad de la Republica, Av. Garzon 780, Sayago, Montevideo, CP, 12900, Uruguay Author Katinas, Liliana Department of Botany, NMNH, Smithsonian Institution, Washington D. C., USA & Division Plantas Vasculares, Museo de La Plata, Paseo del Bosque s / n, CP 1900, La Plata, Argentina text PhytoKeys 2016 2016-02-11 60 1 19 http://dx.doi.org/10.3897/phytokeys.60.6795 journal article http://dx.doi.org/10.3897/phytokeys.60.6795 1314-2003-60-1 FFF9FD2BFFA6FFF4FFBCBC36210FA526 576337 Eriachaenium Sch. Bip. Figures 1 , 2 Eriachaenium Sch. Bip. Flora 38: 120. 1855. TYPE: Eriachaenium magellanicum Sch. Bip. Etymology. From the Greek erion , wool, and the Latin achaenium , a type of fruit, describing the villose fruits. Description. Herbs perennial, dwarf, with stout, oblique to vertical rhizomes that are compressed laterally, stems prostrate to ascending. Leaves alternate; sessile, clasping; blades oblanceolate, pinnately veined, margin entire to undulate-dentate, glabrous to subglabrous above, tomentose beneath. Inflorescence monocephalous, axillar; heads pedunculate, heterogamous, disciform; receptacle epaleate; involucre uniseriate. Florets dimorphic; marginal florets female with staminodes, corolla tubular-funnelform, deeply 4-lobed; central florets bisexual or male with a rudimentary ovary, corolla tubular-funnelform, deeply 5-lobed; anther apical appendages rounded to acute, basally constricted and demarcated from the thecae, anthers dark, basally auriculate with tails very short, smooth to slightly papillose; style bilobed, dorsally papillose. Achenes truncate at the apex, densely pubescent, dimorphic, the marginal achenes conspicuously bigger than the central ones; pappus absent. [modified from Katinas et al. 2008 ] Pollen spheroidal to prolate, spheroidal or elliptic in equatorial view, circular in polar view, medium size, P x E = (30-36 x 24-30) µm . Tricolporate, colpi long with thin margin and microgranulate membrane, mesoaperture diffuse. Exine Mutisia type, microechinate, 2-6 µm thick, slightly slender at the poles. Ratio ectosexine/endosexine: 1:1.5; 1:2. Nexine 1.5 µm thick. SEM: tectum punctate. Habitat and distribution. Genus with only one species, Eriachaenium magellanicum Sch. Bip., endemic to Patagonia in Argentina and Chile (Fig. 3 ). It grows in mud, sand, and pebbles either along the margins of inland somewhat saline lakes or near the coast in estuaries ( Morore 1983 and field observations). Species list. Eriachaenium magellanicum Sch. Bip., Flora 38: 121. 1855.