First record of Geosiris (Iridaceae: Geosiridoideae) from Australasia : a new record and a new species from the Wet Tropics of Queensland, Australia

A new species of Geosiris, an achlorophyllous, mycoheterotrophic herb genus previously known only from Madagascar and Mayotte, has been discovered in the Wet Tropics of Queensland, Australia. This finding marks the first record of the genus in Australasia, significantly expanding its geographic range to the Pacific. The Australian taxon, formally described as Geosiris australiensis B. Gray & Y.W. Low, is distinct from its African counterparts based on key morphological differences, particularly in stigma characteristics. While Geosiris albiflora features a club-like stigma with coherent lobes and Geosiris aphylla has fringed, broad stigmatic lobes, the Australian species exhibits a truncate stigma with a short fimbriate margin. This discovery was made through a detailed morphological analysis, highlighting the importance of stigma characteristics in species distinction within this genus.

Gray, B., & Low, Y. W. (2017). First record of Geosiris (Iridaceae: Geosiridoideae) from Australasia : a new record and a new species from the Wet Tropics of Queensland, Australia. Candollea, 72(2), 249. https://doi.org/10.15553/c2017v722a2