A Reconsideration of the Genus Eurycarpus (Brassicaceae)

Abstract

The Himalayan (Tibet and adjacent Kashmir) endemic Eurycarpus is recognized, and the characters separating its two species from Christolea, Desideria, and Parrya are discussed. The new combination E. marinellii is proposed, and Christolea longmucoensis is reduced to synonymy of E. marinellii. In establishing the genus Eurycarpus, Botschantsev (1955) separated it from what was then the invalidly published genus Ermania Chamisso by the biseriate instead of uniseriate seeds, broadly lanceolate instead of linear fruits, entire instead of dentate leaves, and leafless instead of leafy scapes. However, he probably compared only the type species of both genera because most of these alleged differences do not hold if one compares Eurycarpus with the ten species that Botschantsev recognized in Ermania. Eight of the ten species of Ermania are presently assigned to Desideria Pampanini, and the remaining two, including the type of Ermania, belong to the earlier published Melanidion E. L. Greene. For a discussion on the invalidity of Ermania and the generic limits of Desideria and Melanidion, see Al-Shehbaz (2000). Although the type species of Eurycarpus was originally described in Parrya R. Brown, the two genera are unrelated. Eurycarpus has at least some of the trichomes forked, nonsaccate lateral sepals, terete replums, wingless seeds, and entire stigmas, and it lacks the multicellular glands. By contrast, Parrya has exclusively simple trichomes or the plants are glabrous, strongly saccate lateral sepals, flattened replums, winged seeds, prominently 2lobed stigmas with decurrent, connivent lobes, and often multicellular glands. Desideria differs from Eurycarpus by having dentate, often palmately veined leaves, prominently veined valves with well-developed marginal veins, linear to linear-lanceolate fruits rectangular in cross section, valve apices persistently united with replum, obsolete styles, and 2-lobed stigmas. Eurycarpus has entire, pinnately veined leaves, obscurely veined valves without marginal veins, oblong, elliptic, ovate-oblong, or ovate-lanceolate fruits narrowly elliptic in cross section, valve apices readily free from the replum at dehiscence, welldefined subconical styles, and minute, entire stig-