Spyridium

Abstract: Aim To discover the pattern of relationships of areas of endemism for Australian genera in the plant family Rhamnaceae tribe Pomaderreae for comparison with other taxa and interpretation of biogeographical history. Location Australian mainland, Tasmania and New Zealand. Methods A molecular phylogeny and geographic distribution of species within four clades of Pomaderreae are used as a basis for recognition of areas of endemism and analysis of area relationships using paralogy-free subtrees. The taxon phylogeny is the strict consensus tree from a parsimony analysis of 54 taxa, in four clades, and sequence data for the internal transcribed spacer regions of ribosomal DNA (ITS1-5.8S-ITS2) and the plastid DNA region trnL-F. Results The biogeographical analysis identified five subtrees, which, after parsimony analysis, resulted in a minimal tree with 100% consistency and seven resolved nodes. Three sets of area relationships were identified: the areas of Arnhem and Kimberley in tropical north Australia are related based on the phylogeny of taxa within Cryptandra; the moister South-west of Western Australia, its sister area the coastal Geraldton Sandplains, the semi-arid Interzone region and arid Western Desert are related, based on taxa within Cryptandra, Spyridium, Trymalium and Pomaderris; and the eastern regions of Queensland, McPherson-Macleay, south-eastern New South Wales (NSW), Victoria, southern Australia, Tasmania and New Zealand are related based on Cryptandra, Pomaderris and Spyridium. Tasmania and NSW are related based entirely on Cryptandra, but the position of New Zealand relative to the other south-eastern Australian regions is unresolved. Main conclusions The method of paralogy-free subtrees identified a general pattern of geographic area relationships based on Australian Pomaderreae. The widespread distribution of clades, the high level of endemicity and the age of fossils for the family, suggest that the Pomaderreae are an old group among the Australian flora. Their biogeographical history may date to the early Palaeogene with subsequent changes through to the Pleistocene.

Abstract: The tribe Pomaderreae (Rhamnaceae) currently consists of approximately 180 species in seven genera, endemic to Australia and New Zealand. It is the second largest tribe of Rhamnaceae. We undertook a phylogenetic analysis using internal transcribed spacer (ITS) sequence data from 69 representative species of Pomaderreae and five outgroup taxa. The monophyly of Pomaderreae was confirmed. The clades found in the strict consensus tree are mostly consistent with the currently accepted genera of the tribe. All major clades, except Stenanthemum, received moderate to strong bootstrap and jackknife support. Only the relationship between Siegfriedia and Pomaderris received strong support; relationships between other genera did not receive support above 50%. Taxonomic changes are suggested and a preliminary classification of Pomaderreae is proposed, including the monophyletic genera Cryptandra, Pomaderris, Spyridium and Trymalium. Blackallia and Siegfriedia are monotypic. Two new genera are required: one containing two atypical species of Stenanthemum and the second genus consisting of previously unrelated species from three genera that share a 2-carpellate ovary and a characteristic indumentum. The taxonomic status of Stenanthemum requires further examination. A split of Cryplandra into smaller genera is not supported.

Abstract: Phylogenetic analysis of 69 ingroup-taxa of Pomaderreae using trnL-F sequences confirm the monophyly of the tribe. The analysis was impeded by a paucity of informative characters and the presence of apparently homoplasious indel characters and base changes within the P8 region of the trnL intron: the strict consensus tree of the trnL-F analysis is less resolved and had fewer supported clades than in a previous ITS analysis (Kellermann et al. 2005). The backbone of the cladogram is not supported and relationships between genera/clades are somewhat uncertain. The genera Cryptandra, Stenanthemum and Polianthion are well supported. Pomaderris groups with Siegfriedia and Trymalium, but only individual clades within these genera receive support. Blackallia biloba is related to two atypical species of Stenanthemum and B. connata to Cryptandra, but this grouping depends on the exclusion of homoplasious indel characters. Species of Spyridium only group in one clade when these indels are excluded, otherwise they are located in a polytomy at the base of the cladogram. The results mostly agree with earlier findings using ITS sequence data. Two new genera containing atypical species of Stenanthemum are suggested. A synopsis of the Australian genera of Rhamnaceae is provided.

Abstract: K.R. Thiele1 and J.G. West (Australian National Herbarium, Centre for Plant Biodiversity Research, GPO Box 1600, Canberra, ACT 2601, Australia. 1Corresponding author) 2004. Spyridium burragorang (Rhamnaceae), a new species from New South Wales, with new combinations for Spyridium buxifolium and Spyridium scortechinii. Telopea 10(4) 823–829. Spyridium comprises c. 40 species from southern temperate Australia, characterised by cymose inflorescences, a distinctive floral disk, and schizocarpic fruits in which an indehiscent, papery pyrene containing the seed is shed as the disseminule. Three species from New South Wales, previously included in Cryptandra, belong in Spyridium where they form a small, distinctive group. One of these, Spyridium burragorang K.R.Thiele, is described as new, while new combinations are provided for Spyridium buxifolium (Fenzl) K.R.Thiele and Spyridium scortechinii (F.Muell.) K.R.Thiele.