The morphologically complex and charismatic genus Geleznowia (Rutaceae) is endemic to south-western Australia and faces existing and potential conservation issues associated with land clearing, climate change and commercial harvesting. Two species are currently recognised in the genus, but horticulturally recognised forms and phrase-named taxa reflect additional suspected species diversity. The genus exhibits complicated and subtle patterns of morphological variation that have historically inhibited delimitation of taxonomic entities and, as a result, precluded effective conservation assessments. Here we used ddRAD data from 25 populations across the range of Geleznowia to elucidate genomic diversity in the group in conjunction with morphological re-assessment so as to delimit species and revise the taxonomy. Our analyses consistently identified seven entities that maintain genomic distinctiveness even in sympatry with other entities, supporting the inference of reproductive barriers and lineage divergence. Morphological assessment of more than 300 specimens corroborated these seven taxa. Consequently, we recognise seven species of Geleznowia in Western Australia, retaining G. amabilis K.A.Sheph. & A.D.Crawford, recircumscribing G. verrucosa Turcz., reinstating G. calycina (J.Drumm. ex Harv.) Benth., and naming four new species as G. eximia K.A.Sheph. & A.D.Crawford, G. narcissoides K.A.Sheph. & A.D.Crawford, G. occulta K.A.Sheph. & A.D.Crawford, and G. uberiflora K.A.Sheph. & A.D.Crawford.

Well-preserved leaf fossils from the Middle Eocene Anglesea site in Victoria are assigned to a new species of Megahertzia (M. paleoamplexicaulis R.J.Carp. & Rozefelds), a genus of Proteaceae now represented by a single species, M. amplexicaulis A.S.George & B.Hyland, in the Wet Tropics rainforests of Queensland. Megahertzia-like cuticular remains also occur in the Eocene Mount Hotham assemblage of Victoria, and pollen closely conforming to Megahertzia (i.e. Proteacidites latrobensis W.K.Harris) occurs widely in Cenozoic sediments of Australia and in New Zealand. All these records add to other fossil evidence that many species of Australian rainforest Proteaceae are the last vestiges of formerly much more widespread lineages. The fossil leaves are near-identical in architecture and cuticular features to lobed leaves of M. amplexicaulis, including that they have small teeth, stomata in well-defined areoles, and fine cuticular striations. Moreover, where preserved, the leaf fossils show amplexicaul bases, a unique (apomorphic) trait of the extant species. The apparent absence at Anglesea of simple (unlobed) leaves in Megahertzia and two other taxa of fossil Proteaceae is discussed; this leaf type could have evolved convergently in response to forest canopy heat increase as Australia drifted towards the Equator.

This study of Northern Territory charophytes deals with the tribe Nitelleae in family Characeae. We recognise 16 species of Nitella for the Territory. The list includes seven previously described species (Nitella belangeri, N. biformis, N. congesta, N. heterophylla, N. micklei, N. myriotricha and N. tumulosa, of which N. belangeri and N. tumulosa are newly recorded for the Australian flora), and nine newly described species (N. acanthospora, N. boreali-australis, N. crocodylus, N. limosa, N. martinii, N. nitida, N. oollooensis, N. silicea and N. townsendii). Of the five previously reported Nitella species in the Northern Territory (N. hyalina, N. myriotricha, N. penicillata, N. pseudoflabellata and N. subtilissima), only N. myriotricha is recorded in this study, because the other records were based on erroneous identifications or localities. All Nitella species described here can be distinguished on the basis of their morphology and reproductive arrangement. Keys, illustrations and descriptions of all the species are provided.