• Corpus ID: 82955610

Description of six Lepidosperma species (Cyperaceae) based on type specimens

@article{Barrett2012DescriptionOS,
  title={Description of six Lepidosperma species (Cyperaceae) based on type specimens},
  author={Russell L. Barrett},
  journal={Nuytsia},
  year={2012},
  volume={22},
  pages={295-322}
}

• R. Barrett
• Published 2012
• Environmental Science
• Nuytsia

Barrett, R.L. Description of six Lepidosperma species (Cyperaceae) based on type specimens. Nuytsia 22(5): 295–322 (2012). Many species of Lepidosperma Labill. have been poorly circumscribed, resulting in significant nomenclatural confusion. Full descriptions of six species based solely on type specimens held in the Webb Herbarium in Florence (FI-W) and the Preiss Herbarium in Lund (LD) are presented here in order to facilitate accurate application of the names involved. Descriptions are provided for Lepidosperma costale Nees, L. gladiatum Labill., L. fimbriatum Nees, L. humile (Nees) Boeck., L. longitudinale Labill. and L. squamatum Labill., as well as notes about these species. Introduction The genus Lepidosperma Labill. contains 73 currently named species (Barrett & Wilson 2012) with a large number of unnamed taxa remaining to be described. Determining the correct application of existing names is crucial before any new names are created so as not to increase nomenclatural confusion. Barrett and Wilson (2012) have recently examined all relevant type specimens and chosen lectotypes as required, resolving a great deal of past confusion. There are, however, a number of names that still have some questions about their application or origin. Collections of Labillardière Jacques J.H. de Labillardière collected botanical specimens from south-east Tasmania (Recherche Bay to the northern end of d’Entrecasteaux Channel) and Esperance Bay in Western Australia in 1792–3 while aboard the Recherche under Bruny d’Entrecasteaux, in search of Jean François de Galaup, comte de la Pérouse (Nelson 1974, 1975; Galloway 1988; Horner 1995; Duyker 2003; George 2009). He made the first collections of Australian Lepidosperma and named the genus based on these collections (Labillardière 1805). All of the Lepidosperma species named by Labillardière were stated to have been collected in Tasmania, but it is apparent that this was not necessarily correct, with the collection location of three species being in doubt. As currently circumscribed, two species named 296 Nuytsia Vol. 22 (5) (2012) by Labillardière (L. gladiatum Labill. and L. longitudinale Labill.) occur in both Western Australia and Tasmania, while a third (L. squamatum Labill.) is restricted to Western Australia (first noted by Bentham in 1878). Lepidosperma gladiatum is relatively uniform in its morphology across southern Australia and appears to be a well-defined taxon, so while the exact origin of the type collection is in doubt, the application of the name is not. A description is presented here in case small differences become apparent which will allow the origin of the type specimen to be determined. Lepidosperma longitudinale presents a more complex problem. Its morphology is relatively similar across southern Australia and the presence of more than one entity under this name was not suspected until recent molecular data was obtained that demonstrated a clear divergence between western and eastern populations (Barrett 2012). Lepidosperma exaltatum R.Br. was named from the Sydney region based on populations with open, expanded inflorescences, but this feature appears to be variable across the range of L. longitudinale s. lat. and it is currently treated as one species. It is critical to determine whether the type of L. longitudinale was collected in Tasmania or Western Australia so that the application of the name L. longitudinale can be determined and a new name provided for the Western Australian populations if the type proves to be from Tasmania. If the type of L. longitudinale is shown to apply to Western Australian material, then both names can be applied. Labillardière is known to have received specimens collected in various parts of southern Australia by Jean-Baptiste L.C.T. Leschenault de la Tour as botanist on the Géographe expedition of 1801–1803 under Nicholas-Thomas Baudin (Nelson 1974, 1975; Galloway 1988, specimens at FI-W and P). These collections and locations need to be considered when assessing type material utilised by Labillardière. Collections of Preiss The application of three Lepidosperma species names published by Nees (1846) has been in doubt for some time. The name L. costale Nees has been applied to a large number of distinct taxa in Western Australia. Even when restricted to the complex of species related to the type specimen, complex genetic processes, including polyploidy and hybridisation, make matching the type specimen as closely as possible to an extant population critical (Wallace et al. 2011; Barrett et al. 2012; Wallace et al. in prep.). Two names, L. fimbriatum Nees and L. humile (Nees) Boeck. (originally published as L. lineare R.Br. var. humile Nees) were not taken up in Australia following publication, only recently being added to the formal census of Western Australian flora (Western Australian Herbarium 1998–). Both of these taxa have only relatively recently been recollected. Boeckeler (1874) was one of the few to study the original collections and note the distinctiveness of L. lineare var. humile from L. lineare, raising it to specific rank. These specimens were stated to have been collected ‘in the interior of Western Australia’. The descriptions were inadequate to accurately apply the names to particular taxa without examination of the type specimens held at LD. The matter was further confused for L. fimbriatum as a specimen at G with the same Plantae Preissianae number as the type belongs to a different taxon, leading this name to be synonymised under L. angustatum R.Br. (Govaerts et al. 2007). It remains uncertain whether Johan August Ludwig Preiss received material of these two species (and others bearing similar collection localities) from other collectors, or whether they were collected at the most distant point of his explorations inland from Cape Riche and were without any direct point of reference. Further discussion of Preiss collections can be found in Barrett and Wilson (2012). 297 R.L. Barrett, Description of six Lepidosperma species