Project description:Background:Oxalis corniculata L. is a weed with a world-wide distribution and unknown origin. Though it belongs to a section of the genus from South America, the evidence that this species came from there is weak. Methods:We reviewed the evidence for the origin of O. corniculata using herbarium specimens, historic literature and archaeobotanical research. We also summarized ethnobotanical literature to understand where this species is most used by humans as a medicine. Results:Despite numerous claims that it is native to Europe there is no strong evidence that O. corniculata occurred in Europe before the 15th century. Nor is there reliable evidence that it occurred in North or South America before the 19th century. However, there is direct archaeobotanical evidence of it occurring in south-east Asia at least 5,000 years ago. There is also evidence from historic literature and archaeobotany that it reached Polynesia before European expeditions explored these islands. Examination of the traditional use of O. corniculata demonstrates that is most widely used as a medicine in south-east Asia, which, while circumstantial, also points to a long association with human culture in this area. Discussion:The most likely origin for O. corniculata is south-east Asia. This is consistent with a largely circum-Pacific distribution of section Corniculatae of Oxalis. Nevertheless, it is likely that O. corniculata spread to Europe and perhaps Polynesia before the advent of the modern era through trade routes at that time.
Project description:Oxalis corniculata L. is a perennial herb with a world-wide distribution. In this study, we sequenced the complete chloroplast genome of O. corniculata, which exhibited a circular genome of 155,182 bp in length with 37.5% GC content. The chloroplast genome contained a canonical quadripartite structure with a large single copy (LSC) region of 83,936 bp, a small single copy (SSC) region of 17,048 bp and a pair of 25,581 bp inverted repeats (IRs). A total of 108 unique genes, including 76 protein-coding genes (PCGs), 28 tRNA genes and four rRNA genes were found in this chloroplast genome. The phylogenetic tree was constructed based on O. corniculata and other 11 chloroplast genome sequences, which showed that O. corniculata was closely grouped with of O. corymbosa and O. drummondii.