The twining legume Macroptilium atropurpureum cv. Siratro was released around 1960 (Hutton 1962) and the rust resistant cultivar Aztec was released in 1994 (Bray & Woodroffe 1995). The species showed great potential for pastures in northern Australia and was planted over some 220 Kha in the 1960\u27s and 70\u27s. The species was high yielding and readily eaten by cattle. However, by the early 1980\u27s the species had declined dramatically in grazed pastures. Clements (1989) showed that a major problem with Siratro was the frequency of removal of growing points. This leads to less regrowth after grazing, less seed set and hence less regenerative capacity. Accessions with greater branching characteristics may overcome this problem
