Candelaria and San Ignacio) and Santa Fe. In Uruguay it only occurs to the west in the departments of Paysandú and Río Negro. Bauermann et al. investigated the possibility of using palm pollen, including this species, in palynology, in order to try to provide more detail about the ancient changes in habitat in the state Rio Grande do Sul in Brazil by tracking the changes in distribution and abundance of the palms, but were unable to provide much detail on the subject. Habitat and ecology This slow-growing palm grows to 12-18m tall, with a trunk diameter of 50 cm, in giant, ancient, almost monoculture groves in savannah habitats (called pampa in Brazil). It is usually found in sandy soils, which are often much rockier than that in which other Butia are found. It grows at altitudes of 0-500m. It fruits abundantly in the summer and the seeds germinate in the wild in the spring or the fall. The nuts of this palm are alleged to have been the main diet of the glaucous macaw in 1993, although the taxonomy of local Butia populations has changed somewhat since then. Butia yatay is thought to be one of the natural hosts for larvae (caterpillars) of the giant day-flying moth Paysandisia archon which attack the piths of this palm, along with many other palm species, at least in Europe where the moth has naturalised after likely being introduced from Argentina hidden in the trunks of B. yatay and Trithrinax campestris in consignments of palms imported for ornamental horticulture. An infestation can kill the palm. The moth prefers genera of palm with hairy trunks as the fibre is used in the construction of the cocoon for the pupa; in Europe it prefers Trachycarpus above all, but also Trithrinax or Chamaerops. Horticulture Seeds (or rather, nuts) are collected in Brazil for the international ornamental plant industry. It is advised to plant the palms in full sunlight. It is said to take -12 °C, but should be protected at -5 °C in the Netherlands. It is commonly grown and sold in Japan as an ornamental lawn plant. Conservation In 2008 the conservation status in Brazil was classified as 'data deficient' by the federal Ministério do Meio Ambiente. In 2012 the conservation status in Brazil was evaluated as 'vulnerable' by the Centro Nacional de Conservação da Flora. Although it occurs over an extensive range, both the size