Theories of adaptive radiation propose predictable trajectories in which diversity accumulates rapidly in newly formed or colonized environments with underexploited niche space and few competing species, before slowing down as competition intensifies, and speciation and extinction rates approach equilibrium. This historical perspective on diversity may be more important than current environmental variation for explaining today's biodiversity, but this has been difficult to determine because of the complexity of diversification dynamics and the challenges of relating diversification processes to past environmental change. Here we unravel the complex and heterogenous diversification dynamics of Proteaceae (subfamily Grevilleoideae), a large Gondwanan plant clade, to investigate how the expansion and contraction of biomes since the Cretaceous has shaped its current megadiversity across the Sahul region (Australia and New Guinea). We modeled paleobiome dynamics over a 120 Ma period and produced a nuclear phylogenomic dataset of 458 loci for ~700 species (~74%) to show that historical diversification rates across the Grevilleoideae phylogeny are closely associated with ecological opportunity provided by emerging and expanding biomes. Diversification is rapid in emerging and expanding biomes, while long-occupied biomes tend to have higher species richness but lower diversification rates, as expected if these biomes have approached equilibrium diversity. Our results reveal a strong and heterogeneous legacy of climatic and geological history on today's floristic diversity and explain why diversity is often decoupled from expectations based on measures of ecological "carrying capacity" such as the area or climate of present-day biomes.

Grevillea kulikup Olde is described along with details of habitat, associated flora and conservation status. The recently discovered new species is known from a single population of less than 20 individuals. The most recent key to related species is modified.

Grevillea tesselata Olde is described here as a new species from south-west Western Australia, known only from a small population in a fragmented roadside landscape, and previously recognised under the phrase name Grevillea sp. Trayning (W. Johnston WJ 071). Following the Flora of Australia, the new species keys to the Grevillea Acacioides Group which comprises only three species, G. endlicheriana Meisn., G. acacioides C.A.Gardner ex McGill. and G. gordoniana C.A.Gardner. A binary assessment of 50 morphological characters presented here supports the view that G. acacioides and G. endlicheriana are sister species. A key to the new species is provided and its distribution updated. Grevillea tesselata has a Priority One Conservation Code according to the Western Australian Herbarium.

Grevillea gilmourii Olde and G. milleriana Olde, two species new to science, are described. They are putative members of the Aspleniifolia/Hookeriana Subgroup of the Grevillea Pteridifolia Group. Grevillea gilmourii is separated from G. macleayana (McGill) Olde & Marriott where it had previously been treated as the ‘Deua form’, a geographically disjunct, divided-leaf variant. The separate formal recognition of G. gilmourii here necessitates a revised delineation of G. macleayana to restrict it to populations with undivided leaves only, incorporating recent clarification to terminology in relation to leaf lobing. Grevillea milleriana is a recent discovery from the Maddens Plains area, south of Sydney. Known from a single plant, its recognition as a biological species rather than as a self-sown hybrid is discussed. All three species are linked morphologically and historically to the Victorian species G. barklyana F.Muell. ex Benth., which remains taxonomically unaltered from recent treatments. For the sake of convenience, all four species (G. barklyana, G. macleayana, G. gilmourii and G. milleriana) are grouped informally into an alliance, the Grevillea barklyana alliance, for which diagnostic characters are outlined and two identification keys are given. Both newly described species have divided leaves and are known from only small populations. Conservation recommendations are provided for both new species.

Four species are added to the Grevillea thelemanniana Group, the constituency of which is discussed in light of recent phylogenetic analyses. Two new species are described. Grevillea cooljarloo Keighery and Olde was previously included by some in Grevillea preissii Meisn. subsp. preissii or as G. pinaster divided-leaf form, and is presently known informally as Grevillea thelemanniana subsp. Cooljarloo (B.J. Keighery 28B) by the Western Australian Herbarium. Grevillea gillingarra Olde and Keighery has previously been confused with G. thelemanniana Hügel ex Endl. Grevillea preissii subsp. glabrilimba Olde and Marriott is here recognised at specific rank, as G. glabrilimba (Olde and Marriott) Olde. Grevillea preissii is more narrowly circumscribed, in line with the original concept sensu Meisner (1845), without subspecies. A photo of the Blaschka glass model of Grevillea preissii is included with permission. The historical confusion between G. thelemanniana and G. preissii is revisited. Grevillea variifolia subsp. bundera Keighery is recognised at species-level as G. bundera (Keighery) Olde and Keighery. A conservation assessment for all taxa is provided and a key to the revised Thelemanniana Group, as currently accepted, is supplied.

The correct citation for Grevillea manglesii (Proteaceae) is G. manglesii Pépin (1838). A neotype is here selected from among historic collections, now at Paris (P). Should the minimal description provided by Pépin be successfully challenged as inadequate, the name would not change but the revised authority would be Grevillea manglesii (Graham) A.Baumann and N.Baumann (1843). The origins and complex taxonomic and horticultural history of G. manglesii and its synonyms Manglesia glabrata Lindl., Anadenia manglesii Graham, Grevillea manglesii Hort., Manglesia trilobata Hort. ex Ettingsh., and Manglesia cuneata Endl. are outlined and discussed, together with new insights discerned from James Mangles’ unpublished Letter Books. The important role of Captain James Mangles R.N. to the botany and horticulture of Grevillea manglesii is reviewed and historical errors are corrected. Manglesia glabrata Lindl. is lectotypified. G. ornithopoda Meisn. is reinstated at specific rank and G. dissectifolia (McGill.) Olde is published as a new combination. Both are phenetically diagnosable without intergrades and occur in discrete populations that sometimes overlap the distribution of related species.

The existence of Grevillea merceri Olde & Marriott, herein described, was brought to light following a single collection by the late Ken Newbey in 1963. His specimen was treated by McGillivray and Makinson (1993: 187) as 'unassignable to species' but with possible affinity to G. paniculata Meisn., a species very broadly conceptualised in their work. Revision and a more restricted delimitation of G. paniculata by Olde & Marriott (1994, 1995) clarified the many significant differences from this specimen and others subsequently found. The relationship of G. merceri to other members of the Triloba Group however remains uncertain and awaits phylogenetic analysis.

Grevillea speckiana Olde is described from a single collection gathered in 1953. Although the specimens bears flowers in early bud, fruits and foliage are sufficient to assign and describe the species. Unlike several other species in the Triloba Group awaiting description from single specimens that represent extinct species, there is some hope for its continued existence because of the botanically unexplored locality in which it was collected.

Grevillea trichantha Olde, a rare species in the Triloba Group is described. It was discovered by the author in 2001 and appears to be most closely related to G. metamorpha Makinson, a rare, allopatric species known only from a single population on private land, west of the Brand Highway, in south-west Western Australia. Grevillea trichantha is the third species in the Triloba Group bearing floral organs on which hairs in various degrees of density are consistently distributed, notably on the outer surface of the perianth. A short key differentiating the three species is provided. Grevillea trichantha is more common than its comparator, G. metamorpha, but is still highly localised in distribution so deserves high conservation priority.

Grevillea hortiorum Olde is here described as a new species. It is a member of the Triloba Group sensu Flora of Australia, based on shared morphological characters, and it may be related to Grevillea acrobotrya Meisn. Numerous morphological differences distinguish it as a species, but its relationships have not been tested with phylogenetic data. Subsequent to its initial discovery, when it was thought to be rare, both its distribution and knowledge of populations have been greatly expanded, almost exclusively due to the efforts of its eponymous collectors. It was initially thought to be uncommon and associated with open wandoo woodland, but later collections have been gathered in open heath as well. An interim key to Grevillea hortiorum is provided.

Twenty-one Grevillea species currently comprise the Triloba Group sensu Flora of Australia, or Group 1 sensu The Grevillea Book. All species except the transcontinental species G. anethifolia R.Br. are distributed in south-west Western Australia. Grevillea pieroniae Olde, herein described, is currently treated as Grevillea sp. Stirling Range (D.J. McGillivray 3488 & A.S. George) by the Western Australian Herbarium. It has some affinity with Grevillea anethifolia through shared possession of similar truncate-conical to cylindrical pollen-presenters. Grevillea pieroniae is a rare species that is potentially threatened by Phytophthora cinnamomi, fire frequency, a drying climate, as well as feral and native herbivore-grazing, so requires careful assessment and ongoing monitoring. A short history of the Triloba Group is provided to give context to Grevillea pieroniae and as precursor to other related species soon to be recognised.

A preliminary checklist of more than 360 fossil plants in the Proteaceae is presented, together with details of their publication. The list includes only current and synonymised genera in which extant species are or were recognised. The aim is to reduce the likelihood of new names being taken up with earlier homonyms, ultimately necessitating unfortunate name changes. Lomatia fraxinifolia F. Muell. ex Benth. is an illegitimate homonym and is here replaced with the name Lomatia milnerae Olde. Grevillea trilobata (Hort ex Ettingsh.) Olde, comb. nov., previously incorrectly treated as a fossil, is here recognised as a probable synonym of Grevillea manglesii (Graham) Planch. Hakea salisburiifolia Hügel ex Ettingsh. is recognised as an extant species and treated as a synonym of Hakea baxteri R.Br.

The frequency of evolutionary biome shifts during diversification has important implications for our ability to explain geographic patterns of plant diversity. Recent studies present several examples of biome shifts, but whether frequencies of biome shifts closely reflect geographic proximity or environmental similarity of biomes remains poorly known. We explore this question by using phylogenomic methods to estimate the phylogeny of Hakea, a diverse Australian genus occupying a wide range of biomes. Model-based estimation of ancestral regions indicates that Hakea began diversifying in the Mediterranean biome of southern Australia in the Middle Eocene-Early Oligocene, and dispersed repeatedly into other biomes across the continent. We infer around 47 shifts between biomes. Frequencies of shifts between pairs of biomes are usually similar to those expected from their geographic connectedness or climatic similarity, but in some cases are substantially higher or lower than expected, perhaps reflecting how readily key physiological traits can be modified to adapt lineages to new environments. The history of frequent biome-shifting is reflected in the structure of present-day assemblages, which tend to be more phylogenetically diverse than null-model expectations. The case of Hakea demonstrates that the radiation of large plant clades across wide geographic areas need not be constrained by dispersal limitation or conserved adaptations to particular environments.

The recent recognition of Triunia kittredgei Olde (Olde 2015) has been challenged by G.P. Guymer and P. Forster (2015) who have suggested that the name should be rejected and that the application of previous names should continue to apply in the genus Triunia L.A.S.Johnson & B.G.Briggs. They have argued that two varietal lectotypifications in Helicia youngiana C.Moore & F.Muell. by H. Sleumer (1955), varieties later recognised as species in the genus Triunia, should be overturned in favour of two later lectotypifications by D. Foreman (Foreman 1986). Their arguments are here separately examined and refuted.

PREMISE OF THE STUDY: Subtribe Hakeinae (526 spp.) represents a large Australian plant radiation central to our understanding of that flora's evolution and ecology. It contains Grevillea-the third largest plant genus in Australia and a group inferred to have among the highest diversification rates in the angiosperms. However, we lack a robust phylogenetic framework for understanding subtribe Hakeinae and recognize that Grevillea lacks an unambiguous synapomorphy supporting its monophyly.METHODS: We used four plastid and one nuclear DNA region from a taxonomically even sampling of a third of the species to infer a time-calibrated phylogeny of Hakeinae and absolute diversification rates of major clades. We developed the R package addTaxa to add unsampled taxa to the tree for diversification rate inference.KEY RESULTS: Grevillea is paraphyletic with respect to Hakea and Finschia. Under most parameter combinations, Hakea contains the major clade with the highest diversifi cation rate in Hakeinae, rather than Grevillea. The crown age of the Grevillea + Hakea + Finschia crown group is about double that of prior estimates.CONCLUSIONS: We demonstrate that the paraphyly of Grevillea considerably enlarges the number of Australian descendants from its most recent common ancestor but has also misled investigators who considered a single operational taxonomic unit as adequate to represent the genus for inferences of diversifi cation rate and timing. Our time-calibrated phylogeny can form the basis of future evolutionary, comparative ecology, and biogeography studies involving this large Australian plant radiation, as well as nomenclatural changes.

The Hakeinae, a subtribe of Embothrieae, Proteaceae, consists of five genera, Buckinghamia, Opisthiolepis, Grevillea, Hakea and Finschia. The genera are discussed with respect to their suitability for horticulture and commerce. Particular reference is made to Buckinghamia celcissima, some new Grevillea cultivars, Grevillea 'Goliath' and Grevillea 'Bulli Beauty' and the Western Australian species (Grevillea eriobotrya) recently introduced to commercial use as cut flowers and garden subjects. Some observations are made on older cultivars, fertility, their cultivation, maintenance, breeding and utility as cut flowers or foliage.

A morphological study of living plants and herbarium specimens has here resulted in the formal recognition of two parapatric subspecies in Grevillea laurifolia Sieber ex Spreng., the autonymic subsp. laurifolia, and the novel subsp. caleyana P.M.Olde. Some critical phenetic characters show a strong morphological approach in specimens collected around Wentworth Falls which suggests that this area is a narrow geographic zone where the two subspecies intergrade. Notwithstanding the morphological approach all specimens examined were classifiable in one or other subspecies on the basis of their pistil lengths. A key to the subspecies of Grevillea laurifolia, descriptions of all taxa discussed, notes on conservation status and distributional information are provided.

A morphological study of living plants and herbarium specimens has here resulted in the formal recognition of two parapatric subspecies in Grevillea laurifolia Sieber ex Spreng., the autonymic subsp. laurifolia, and the novel subsp. caleyana P.M.Olde. Some critical phenetic characters show a strong morphological approach in specimens collected around Wentworth Falls which suggests that this area is a narrow geographic zone where the two subspecies intergrade. Notwithstanding the morphological approach all specimens examined were classifiable in one or other subspecies on the basis of their pistil lengths. A key to the subspecies of Grevillea laurifolia, descriptions of all taxa discussed, notes on conservation status and distributional information are provided.

The name Triunia kittredgei P.M. Olde replaces Triunia robusta sensu D. Foreman (1986) following an invalid lectotypification. Triunia erythrocarpa Foreman is referred to synonymy under Triunia robusta, correctly applied. The lectotypes of T. robusta and T. montana were apparently not distributed to NSW as indicated by Sleumer (1955) and replacements are here redesignated from among the existing isolectotypes. The holotype of Triunia youngiana was not collected by Charles Moore as indicated by Moore and Mueller (1864), and Sleumer (1955) who typified the name with Moore’s collection number 4 at MEL. The evidence points to the collection Richards 4 as the holotype.

Grevillea tetragonoloba (Proteaceae: Grevilleoideae) recircumscribed, with notes on its typification and a new segregate species, Grevillea nivea, described