Australia is known for its unusual flora and fauna, but this little flower is particularly unique. The Western Underground Orchid, Rhizanthella gardneri, has been identified in just five populations in western Australia. Growing completely under several centimeters of soil, the plant has no leaves or other green tissue, as it does not rely on photosynthesis for energy. Instead, it relies on the mycorrhizal fungi associated with the broom bush plant. The floral organ is a capitulum containing several disk florets, and the plant is capable of reproducing either sexually or vegetatively. A study completed in 2011 (Delannoy et al.) found a high level of gene loss in the plastid genome, resulting in a total of 20 proteins and 13 RNAs encoded. The authors compared this to other non-photosynthetic plants, and their results suggest a specific minimal set of genes that are required for plastomes.
--Erin Patterson