Trichopetalum is a genus with tuberous roots found in Australia and South America. It is related to Thysanotus and Arthropodium and grows in much the same way. You sometimes see it included in Anthericaceae which the Angiosperm Phylogeny Group II, 2003 suggests could optionally be included in the Agavaceae or the Asparagaceae family. Another possibility is the Laxmanniaceae family.
Trichopetalum plumosum is the only species of the genus from South America (Chile). It is 20cm. (8in.) tall with white flowers that bloom in spring. It grows in full sun in grassy slopes of hills in well-drained neutral to alkaline soil. It is dormant in summer and may not be hardy as there are only slight frosts in its native habitat. However, Jane McGary has grown it from seed to flowering in an unheated bulb frame where it survived temperatures as low as 20 degrees F. Information courtesy of Alberto Castillo. Photo 1 by Sheila Burrow. Photos 2-3 from Osmani Baullosa. Photo 4 taken by Eugene Zielinski spring 2011 in Chile along Route 5 between Los Vilos and La Serena. The elegant flowers are small, barely 1.3 cm (1/2 inch) wide.