TL;DR: It is argued for retaining Caladenia in the broad sense, largely reflecting Robert Brown's original concept, differing only in the recognition as genera of Cyanicula, Pheladenia, and Leptoceras, as well as two monotypic genera not known to Brown but later described as species ofCaladenia (Praecoxanthus and Ericksonella).
Abstract: Nomenclatural confusion has been generated regarding the large Australasian terrestrial orchid genus Caladenia following publication from 2001 onwards of three major treatments of Caladeniinae. Here, we review concepts for Caladenia and allied genera in the subtribe, we revise three sister genera of Caladenia (Cyanicula, Ericksonella and Pheladenia), and we present an annotated nomenclatural checklist with many new synonymies and some new combinations. A revised circumscription of ten genera in the Caladeniinae is presented, including both Adenochilus and Eriochilus, which have recently been segregated as monogeneric subtribes by others. We argue for retaining Caladenia in the broad sense, largely reflecting Robert Brown's original concept, differing only in the recognition as genera of Cyanicula, Pheladenia, and Leptoceras, as well as two monotypic genera not known to Brown but later described as species of Caladenia (Praecoxanthus and Ericksonella). Thus Caladenia remains a large Australasian genus of terrestrial orchids with 243 species and six subgenera. This approach maximises nomenclatural stability while ensuring that hypothesised monophyly is upheld in the light of molecular phylogenetics analyses. The valid type for Caladenia is C. carnea, while that for Caladenia sect. Calonema is C. longicauda. The genus Jonesiopsis and generic combination Phlebochilus (Benth.) Szlach. were validly published. These conclusions call into question many recently erected taxa and combinations of other authors. Synonyms of Caladenia include Arachnorchis, Calonemorchis, Drakonorchis, Jonesiopsis, Petalochilus, Phlebochilus and Stegostyla. Pentisia is a synonym of Cyanicula. Calonema (Lindl.) Szlach. and Calonema (Lindl.) D.L. Jones and M.A. Clem. are invalid generic combinations as the name Calonema had already been used for a fungal genus. New taxa described herein include Ericksonella, Cyanicula subgenus Trilobatae, C. aperta, C. ixioides subsp. candida, × Cyanthera and × C. glossodioides. New combinations include Caladenia subgenus Stegostyla (D.L. Jones and M.A. Clem.) Hopper and A.P. Br., C. graniticola (Hopper and A.P. Br.) Hopper and A.P. Br., C. saccata (R.S. Rogers) Hopper & A.P. Br., C. orientalis (G.W. Carr) Hopper & A.P. Br., and C. villosissima (G.W. Carr) Hopper & A.P. Br., and Ericksonella saccharata (Reichb.f.) Hopper and A.P.Br.
TL;DR: Leaf anatomy of 25 species in 15 genera of Caladeniinae (Diurideae, Orchidaceae), excluding Caladenia, was investigated to determine diagnostic characters to be used in forthcoming, broad-based cladistic analyses of the subtribe and to assess interspecific and intergeneric relationships.
TL;DR: A detailed study of taxonomic features of the Eriochilus dilatatus (Orchidaceae) complex (white bunny orchids) in Western Australia found that there were no consistent differences among most subspecies when herbarium specimens or living plants were compared.
Abstract: A detailed study of taxonomic features of the Eriochilus dilatatus (Orchidaceae) complex (white bunny orchids) in Western Australia found that there were no consistent differences among most subspecies when herbarium specimens or living plants were compared. These subspecies were originally segregated primarily by differences in leaf size and shape and the number of flowers produced, but a critical examination of herbarium specimens found that these features were highly inconsistent within taxa. These features were also found to be highly variable over time and space within populations of living plants. The distribution patterns, habitat preferences and flowering times of these taxa were found to overlap, even for subspecies brevifolius and orientalis, which occupy the northern and eastern limits of the distribution of this species. Eriochilus dilatatus subsp. magnus and subsp. multiflorus were shown to be synonyms of subsp. dilatatus, whereas subsp. undulatus and subsp. orientalis are synonymised under subsp. brevifolius. As a result of this study, the two recognised subspecies are subsp. dilatatus and subsp. brevifolius, which can be readily separated by plant height, flower numbers and leaf morphology, except for a few intermediate plants where ranges overlap. New keys and descriptions to these taxa are provided. The reasons for previous taxonomic confusion in this group and in many other Western Australian orchids are discussed and research approaches to resolve these issues are suggested.
TL;DR: Serendipita is one of the main fungal genera that form mutualistic associations with species of orchids (Orchidaceae) as discussed by the authors, and seven new species associated with various Australian orchid genera are described.
Abstract: Serendipita is one of the main fungal genera that form mutualistic associations with species of orchids (Orchidaceae). Here, seven new Serendipita species associated with various Australian orchid genera are described. These Serendipita species were originally characterized by multilocus DNA sequence species delimitation analyses (three mtDNA and four nuclear genes) and confirmed as distinct with addition of further isolates and reanalysis of nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS) and nuc 28S rDNA (28S). Culture morphology and microscopic features are presented for each species, three of which are binucleate and four multinucleate. For the ITS region, the seven species have within-species sequence divergence between 1.07% and 4.31%, and all but one of the species pairs is separated by interspecific divergence of at least 4.35%. The newly described Serendipita species, S. australiana, S. communis, S. occidentalis, S. rarihospitum, S. secunda, S. talbotii, and S. warcupii, are shown to be separate species from S. vermifera on the basis of comparison against a sequence from the type. Isolates originally identified by Warcup as Sebacina "vermifera" from Caladenia orchids are revised and shown to belong to three of the species newly described here. Some non-Caladenia isolates identified by Warcup as S. "vermifera" are also shown to be non-conspecific with the type of S. vermifera. On the basis of ITS sequences, 346 isolates from 26 other studies, previously identified under provisional designations, are accommodated under the novel species. The species of Serendipta described here associate with the Australian orchid genera Caladenia, Cyanicula, Elythranthera, Ericksonella, Eriochilus, Glossodia, and Pheladenia. Most of the novel Serendipita species occur widely across Australia, often with widely distributed hosts, but one species, Serendipita rarihospitum, associates with narrowly distributed orchid species.