Phylogeny, classification and biogeography of Philotheca sect. Erionema (Rutaceae) based on nrDNA sequences Author Batty, Erin L. Author Holmes, Gareth D. Author Murphy, Daniel J. Author Forster, Paul I. Author Neal, Will C. Author Bayly, Michael J. text Australian Systematic Botany 2022 2022-09-16 35 4 326 338 http://dx.doi.org/10.1071/sb22003 journal article 10.1071/SB22003 1446-5701 10904183 Polyphyly of Philotheca glasshousiensis The polyphyly of P. glasshousiensis provides strong evidence that northern and southern populations should be recognised as two distinct species. The southern populations, from the Glasshouse Mountains and Mount Cooroora, represent P. glasshousiensis sensu stricto , the type being from the Glasshouse Mountains (Mount Coonowrin). These southern populations are most closely related to but clearly distinct from P. queenslandica , being separated by long branches on the phylogenetic tree ( Fig. 2 ). Although these two species both occur in south-eastern Qld, there is a clear ecological separation between them, with P. glasshousiensis growing in rocky areas towards the summits of the mountains and P. queenslandica restricted to lowland heaths in wallum vegetation that is periodically inundated. Herbarium specimens from the northern populations, at Cania Gorge (not sequenced here) and Kroombit Tops, were included in the circumscription of P . glasshousiensis (or P. myoporoides subsp. leichhardtii (Benth.) Paul G. Wilson ) by Bayly (1998) and Forster (2005) on the basis of morphological resemblance and their occurrence in similar cliff line habitat. Our recent, preliminary comparisons indicate that, although the northern populations resemble P. glasshousiensis sensu stricto in most qualitative features (many of which are highly conserved across sect. Erionema ), they usually have larger leaves than those of P. glasshousiensis sensu stricto but there is overlap in leaf sizes. More detailed study is needed to clarify the extent to which the two genetic groups can be distinguished morphologically.