EUDEMA Humboldt & Bonpland, Pl. Aequinoct. 2: 133. 1813.
Ihsan A. Al-Shehbaz
Name derivation: for Eudemus of Rhodes (ca. 370−300 BC.) an ancient Greek philosopher, a student of Aristotle, and the first historian of science.
Lectotype species (designated by Al-Shehbaz, 1990: 100): E. rupestris Humboldt & Bonpland.
Herbs, perennial, scapose, with rhizomes or caudex, basally with petiolar remains of previous years. Trichomes simple or dendritic, rarely absent. Multicellular glands absent. Stems absent. Basal leaves petiolate, fleshy or not, rosulate, simple, entire or rarely pinnately lobed or dentate; cauline leaves absent. Inflorescences solitary flowers on long pedicels originating from axils of rosette leaves, maturing centripetally; fruiting pedicels ascending to divaricate or recurved, persistent. Sepals ovate or oblong, free, deciduous, erect, equal, base of inner pair not saccate. Petals white, creamy white, or yellow, erect at base with flaring blade, longer than sepals; blade obovate, spatulate, oblanceolate, or sublinear, apex obtuse or rounded; claw not differentiated from blade. Stamens 6, slightly or exserted, erect, slightly tetradynamous; filaments filiform, wingless, unappendaged, not dilated at base, glabrous; anthers ovate or oblong, rounded at base, not apiculate at apex. Nectar glands 4, distinct; median nectaries absent; lateral nectaries 1 on each side of lateral stamens. Ovules 2-60 per ovary; placentation parietal. Fruit dehiscent, capsular silicles, oblong, ovate, obovate, ovoid, pyriform, orbicular, or subglobose, terete, or slightly to strongly flattened and latiseptate or angustiseptate, unsegmented; valves papery, veinless, glabrous, keeled or not keeled and flat or rounded, smooth, wingless, unappendaged; gynophore absent; replum rounded; septum complete or reduced to a rim, membranous, not veined; style obsolete or distinct and to 3 mm, filiform, glabrous, persistent; stigma capitate, entire, unappendaged. Seeds biseriate, wingless, oblong to ovoid, plump or sligtly flattened; seed coat coarsely reticulate, not mucilaginous when wetted; cotyledons incumbent, entire.
Six species: South America (Argentina, Bolivia, Chile, Ecuador. Peru).
Reference: Al-Shehbaz (1990a).