Levenhookia

''Levenhookia'', also known as the styleworts, is a genus of ten recognized species in the family Stylidiaceae and is endemic to Australia. The genus is restricted to Western Australia almost exclusively with a few exceptions: '' L. pusilla'''s range extends into South Australia, '' L. dubia'''s range extends through South Australia into Victoria and New South Wales, '' L. sonderi'' is native only to Victoria, and '' L. chippendalei'' is also found in the Northern Territory.Erickson, R. and Willis, J.H. (1966). Some additions to Australian Stylidiaceae. ''Victorian Naturalist'', 83: 107-112.Carlquist, S. (1969). Studies in Stylidiaceae: New taxa, field observations, evolutionary tendencies. ''Aliso'', 7(1): 13-64.

All species of ''Levenhookia'' possess a sensitive labellum that performs a similar function to the column of ''Stylidium'' species. The labellum responds to touch and enables the plants to promote cross-pollination and avoid self-pollination. Most species of ''Levenhookia'' are ephemeral plants that prefer sand heath habitat. ''Levenhookia'' species also possess glandular trichomes similar to those of its sister genus, ''Stylidium''. While no studies have been done to test ''Levenhookia'' for carnivory, it is plausible that they are carnivorous plants like the related ''Stylidium'' species.Darnowski, D.W., Carroll, D.M., Płachno, B., Kabanoff, E., and Cinnamon, E. (2006)
Evidence of protocarnivory in triggerplants (''Stylidium'' spp.; Stylidiaceae)
''Plant Biology'', 8(6): 805-812.

Evolution and taxonomy

The genus is known to be closely related to the genus '' Stylidium''. Specifically, the subgenus '' Centridium'' is the subgeneric taxonomy in the genus ''Stylidium'' that appears to be most closely related to ''Levenhookia'' and most suggests an ancestral relationship. Sherwin Carlquist notes that ''Levenhookia'' is most likely a derivative of ''Stylidium'' and has relied on outcropping as its mode of evolution. The species in this genus represent a series from '' L. preissii'', which requires cross pollination for reproduction, to ''L. dubia'', which relies on facultative self-pollination. In an earlier publication, Rica Erickson described this series in reverse, suggesting that path as the evolutionary sequence.Erickson, R. (1958). ''Triggerplants''. Paterson Brokensha Pty., Ltd., Perth, Australia. Several species of ''Stylidium'' have also been noted to mimic flower morphology of certain ''Levenhookia'' species to utilize similar available pollinators. Specifically, '' S. xanthopis'' mimics '' L. leptantha'' and '' S. ecorne'' mimics '' L. pauciflora''.

Three sections have been established and described by Johannes Mildbraed in 1908 to separate the subgeneric taxonomy in this genus. Section '' Coleostylis'' consists of ''L. chippendalei'', ''L. preissii'', '' L. stipitata'', and possibly '' L. octomaculata'', which Erickson described in 1956, noting its affinities with ''L. stipitata'' but without placing it in a section.Erickson, R. and Willis, J.H. (1956). Critical notes on Australian Stylidiaceae, with descriptions of three new species and two new varieties. ''The Victorian Naturalist'', 72: 130-136. Section '' Estipitatae'' consists of ''L. dubia'', ''L. leptantha'', and ''L. sonderi'', which was considered by Mildbraed to be a variety of ''L. dubia''. Section '' Levenhookia'' consists of ''L. pusilla'' and ''L. pauciflora'', though it could also contain '' L. pulcherrima'', which Carlquist described in 1969 and noted its close association to the other two species in section ''Levenhookia'' but neglected to place it within a section. Section ''Levenhookia'' was originally described by Mildbraed as section ''Eulevenhookia'', which was later changed to the current section title ''Levenhookia'' as an autonym since it is the type section.Mildbraed, J. (1908). Stylidiaceae. In: Engler, A. ''Das Pflanzenreich: Regni vegetabilis conspectus''. IV. 278. Leipzig.The International Plant Names Index (2004)
''Levenhookia'' sect. ''Eulevenhookia'' Mildbr.
Accessed 11 August 2007.

References

{{Taxonbar, from=Q4358645

Asterales genera
Antonie van Leeuwenhoek