Abstract: The range of available sown pasture legumes for the vast heavy clay soil regions of northern Australia has long been regarded as being deficient (Burt 1993; Jones and Clem 1997; Pengelly and Conway 2000). Indeed immense areas of northern Australia’s semi-arid clay soil regions have nosown pasture legume with proven adaptation and persis-tence through the long annual dry seasons (Gardiner and Swan 2008). The genus Desmanthus is a Mimosaceae le-gume containing some 24 species which are native to the Americas and range from being herbaceous to suffruticose in habit (Luckow 1993). Desmanthus is one of the very few legumes consistently observed to persist under heavy graz-ing on clay soils in their native environments (Pengelly and Conway 2000). Numerous accessions of Desmanthus were collected and introduced into Australia by various institu-tions, notably CSIRO and QDPI, over the past 50 years (Reid 1983; Pengelly and Liu 2001), as potential legumes for clay soils. After years of multi-site field evaluation of Desmanthus and other species, in 1991 QDPI released 3 Desmanthus cultivars, cvv. Marc (D. virgatus), Bayamo (D. leptophyllus) and Uman (D. pubescens), which were mar-keted as a blend named “Jaribu” (Cook et al. 1993). Currently, only cv. Marc is available commercially with a focus on southern subtropical Queensland markets. How-ever, Pengelly and Conway (2000) state that, owing to Marc’s low dry matter production, its contribution to ani-mal diets and soil N is limited.