Revision of Oxalis sect. Caesiae, Carnosae, and Giganteae (Oxalidaceae, Oxalidales)
Althought the entire genus Oxalis has been revised carefully as result of a life long effort of Alicia Lourteig (published in 1994 and 2000), species delimitation of the three sections in the Atacama Desert still remain problematic. This is mainly due to two major problems: (1) The entire region has been sparcely and unevenly collected. (2) Succulent taxa of Oxalis sect. Carnosae and Giganteae are not well suited to be preserved as herbarium specimens as they fall apart at the pulvini causing the loss of leaflets, petioles, peduncels, and flowers thereby leaving the investigator in the worst case with one single stem axis.

Fortunately all these species will germinate easily in the greenhouses and can be cultivated there without major problems for decades as all of them are perennials. Owing to this, a revision based on life material seemed promising and this work began in 2004 as part of my Diploma thesis. Three field trips to the Atacama Desert in 2004, 2005, and 2006 tried to add more relevant accessions and to correct for past uneven sampling. Still there is much information lacking and some of the taxa are extremely rare and/or narrow endemics so that a conclusive delimitation of species must await the addition of much more samples. Nevertheless, I hope to conclude a preliminary revision during the next months that will shed some light on the issue and might stimulate further research.