Mycoheterotrophic Plants

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Rhizanthella slateri (Rupp) Clements and Cribb 1984

Rhizanthella slateri was first described by Rupp (1932) as Cryptanthemis slateri, who described specimens found in 1931 (Slater) near Bulahdelah, on the East coast of New South Wales, Australia. Similar to the discovery of Rhizantella gardneri in 1928 this discovery has been made by coincidence. The finder was actually looking for Dipodium punctatum and was scraping away dead leaves and debris off the surface of the earth. After the first specimen, which was quite whithered, there were only 4 more individuals of this species found, until the publication of his description. The specimens were in bad condition, making the analysis more difficult. Rupp (1932) was aware of the "sensational" find of Rhizanthella gardneri a few years earlier and acknowldged the similarity to it. Nonetheless he proposed this new genus, in accordance with Rogers, in the subtribe Rhizantellinae, and called it Cryptanthemis. Several distinctions were noted: "sepals and petals being membranous, flower continuos, with the immature ovary, but the point of union quite obvious", while Rhizanthella had succulent flowers, which are directly continous with their ovaries, so that the point of union is externally obscure". The sepals and petals in C. slateria were quite free, while in Rhizantella they are more or less connate into a tube or bell. The labellum in Rhizantella is relatively large and on a very short claw while in Cryptanthemis it is small, in central flowers minute and the claw varies in lenght and is in central flowers as long as the labellum. The last differentiation made is in the characteristic of the column wich is in this species quite free and has two apical appendages and in Rhizantella its at least partly adnate to the dorsal speal and has no appendages. Horizontal rhizome branches are only noted in Rhizantella gardneri. Despite all of these described distinctions of the genera, Clements & Cribb (1984) proposed a translocation to Rhizanthella, which is the accepted name today. Clements & Cribb (1984) noted mistakes in the description of Rupp (1932), probably made due to the bad condition of the specimens. They also noted that this species was not seen in the 20 years before 1984. The publication shows drawings of the plant and compares Rhizanthella with similar genera. The authors see the genus Rhizantella "most likely to being a member of Diurdieae, which is the best represented tribe in Australian orchid flora".The habitat of R. slateri is barren and stony, as is the habitat of Rhizantella gardneri, but the occurence is not strictly bound to the presence of a certain Melaleuca species, as it is generally found in Eucalyptus forests. Sights of this species are very rare and samples include 12 specimens from the typelocality, another site on the border to Queensland in Lamington National Park and near Springwood in the Blue Mounains near Sydney.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith