I'm not sure if this is correct. I'm trying to split megalorrhiza into two taxa: megalorrhiza for Peru, and mirbelii for central Chile. See comments below.

The name O. megalorrhiza belongs to an apparently endemic Peruvian plant with exceptionally large root tubers. It has been misapplied to a Chilean plant from Valparaíso that is widespread in cultivation and correctly known as O. mirbelii. O. megalorrhiza is not known to be self-fertile and has glaucous, dark green, often red-tinted leaves, whereas O. mirbelii is self-compatible, quickly spreads from seed, and has bright green, shiny leaves. O. megalorrhiza is readily distinguished from the dwarf high-altitude O. pachyrrhiza by its larger flowers and frequently red-flushed leaves, occurring mainly in coastal lomas. Lourteig (2000) used outer sepal shape (hastate with blunt angles in O. megalorrhiza vs. subequilateral with acute angles in O. pachyrrhiza), which unfortunately has resulted in the recognition of a mixture of taxa under this name in her revision.

O. megalorrhiza, now mirbelii in Chile, is distributed between rocks along the coast from Pichidangui to Hualpén near Concepción in a Mediterranean-type climate, following the distribution of megalorrhiza when mirbelii was still a synonym in http://www.christophheibl.de/Diplomarbeit.pdf

Flags for megalorrhiza is the same, and here https://www.inaturalist.org/flags/658293

sources:

Shaw, J M H 2021. The identity of Oxalis megalorrhiza - a 300-year puzzle, Cactus World 39(1)67-72

Shaw, J M H 2022. Shaw, J.M.H. Oxalis OXALIDACEAE. In: Eggli, U., Nyffeler, R. (eds) Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants. Springer, Cham. https://doi.org/10.1007/978-3-030-93492-7

@loarie Scott, when possible, can you help us with this? 'm a little confused with this procedure.