6. Eudema werdermannii O. E. Schulz, Notizbl. Bot. Gart. Berlin-Dahlem 10: 462. 1928; TYPE: Chile. Prov. Atacama, Depto. Copiapó, Cord. Río Figueroa, Co. Paredones, ca. 4300 m, Jan 1926, E. Werdermann 974 (holotype, B!, fragments BAA!; isotypes, BAA!, BM!, CAS!, E!, F!, G, GH!, K!, LIL!, M!, MO!, NY!, S!, UC!, US!, Z!).
Plants cespitose rhizomatous, forming dense cushions; rhizomes branched, 1-2.5 mm wide, with sessile, ovate to lanceolate scales at nodes. Leaves rosulate, somewhat fleshy, petiolate; petioles ciliate with simple or furcate trichomes, somewhat flattened at base; leaf blade narrowly oblanceolate to spatulate, (3-)8-20(-30) mm, (0.7-)1-2(-3.5) mm wide, abaxially glabrous, adaxially densely pubescent with dendritic trichomes, rarely glabrescent or only ciliate, base attenuate, margin entire, apex obtuse or rounded. Sepals oblong, 3-4 mm, 1.4-1.8 mm wide, erect, sparsely pubescent with dendritic trichomes, margin scarious; petals creamy white to yellow, oblanceolate, (4.5-)5-7 mm, 1.5-2 mm wide, apex rounded; filaments erect, slender, 2.5-3.5 mm; anthers oblong, 0.8-1 mm. Fruiting pedicels 3.5-20 mm, glabrous. Fruit sessile, suborbicular, 2.5-3 mm in diam., strongly latiseptate; valves thin, obscurely veined; septum reduced to a narrow rim, hyaline; style 0.2-0.8 mm. Seeds 6-10 per fruit, brown, ovoid, 0.9-1.2 mm, 0.6-0.8 mm wide.
Flowering: Oct-Jan.
Habitat: gravel, puna vegetation, volcanic sand.
Elevation: 3800-4700 m.
Distribution: Argentina (Jujuy, La Rioja, Salta, San Juan), Peru (Arequipa).