Phytotaxa 300 (1): 001–308 ISSN 1179-3155 (print edition) http://www.mapress.com/j/pt/ PHYTOTAXA Copyright © 2017 Magnolia Press Monograph ISSN 1179-3163 (online edition) https://doi.org/10.11646/phytotaxa.300.1.1 PHYTOTAXA 300 A monograph of Daviesia (Mirbelieae, Faboideae, Fabaceae) MICHAEL D. CRISP1, LINDY CAYZER1,2, GREGORY T. CHANDLER1,3 & LYN G. COOK4 1Research School of Biology, The Australian National University, Acton, Australian Capital Territory 2601, Australia. Email: [email protected] 2Present address: Australian National Herbarium, Centre for Plant Biodiversity Research, GPO Box 1700, Canberra, Australian Capital Territory 2601, Australia. Email: [email protected] 3Present address: Department of Agriculture and Water Resources, 1 Pederson Road, Eaton, Northern Territory 0812, Australia. Email: [email protected] 4School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia. Email: [email protected] Magnolia Press Auckland, New Zealand Accepted by James Boatwright: 31 Jan. 2017; published: 24 Mar. 2017 1 Licensed under a Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0 MICHAEL D. CRISP, LINDY CAYZER, GREGORY T. CHANDLER & LYN G. COOK A monograph of Daviesia (Mirbelieae, Faboideae, Fabaceae) (Phytotaxa 300) 308 pp.; 30 cm. 24 March 2017 ISBN 978-1-77670-108-7 (paperback) ISBN 978-1-77670-109-4 (Online edition) FIRST PUBLISHED IN 2017 BY Magnolia Press P.O. Box 41-383 Auckland 1346 New Zealand e-mail: [email protected] http://www.mapress.com/j/pt/ © 2017 Magnolia Press All rights reserved. ISSN 1179-3155 (Print edition) ISSN 1179-3163 (Online edition) 2 • Phytotaxa 300 (1) © 2017 Magnolia Press CRISP ET AL. Abstract Daviesia is a clade of scleromorphic shrubs that are endemic to Australia and its near offshore islands, where it is the largest genus of Fabaceae subfam. Faboideae, with 131 species recognised here. The genus is distributed throughout the continent and occurs in all major habitats except wetlands, rainforest and the alpine zone. This is the first monograph of the genus published since Bentham’s in 1864, which included only 55 species. New taxa described herein are D. divaricata subsp. lanulosa, D. filipes subsp. terminalis, D. subulata, D. schwarzenegger and D. scabrella. New combinations with a change of rank are D. aphylla, D. decurrens subsp. hamata and D. implexa, while D. devito is raised from subspecies level and given a new epithet. A key to species and subspecies, detailed comparative descriptions, phenology and habitat information, as well as line drawings or photographs, are presented for all species. Conservation status is given for taxa of concern, mostly based on assessments by government agencies. A new molecular phylogenetic analysis using sequences of chloroplast and nuclear ribosomal DNA is presented and used to arrange the species descriptions, where the 13 unsequenced species are interpolated using morphological similarity. Seven strongly supported clades and seven mostly well-supported subclades are named informally for reference in discussion of affinities, but are not formally described because they lack morphological synapomorphies. Introduction Daviesia Smith (1798: 220) is the most diverse genus of pea-flowered legumes in Australia, with ca. 130 known species and 18 non-autonym subspecies. Pultenaea Smith (1794: 35) and Gastrolobium Brown (1811: 16)—in its expanded circumscription, Chandler et al. 2002—are the next most diverse, with ca. 110 species each. Like much of the flora of Australia’s abundant oligotrophic soils (Hooker 1860, Orians & Milewski 2007, Crisp & Cook 2013), Daviesia is characterised by its scleromorphic vegetative parts, which are particularly well developed. The leaves are usually hard and isobilateral, often spinescent and/or cylindrical in section, or vertically compressed, or reduced in size, sometimes to scales. They closely resemble the phyllodes of Acacia Miller (1754: [25]), and are here termed as such, though they likely evolved convergently in these two genera (Crisp & Weston 1987: 100). Three species have flattened, leaf-like cladodes (D. alata, D. epiphyllum and D. pteroclada). The roots of many species are bizarre, having a strange mode of secondary thickening in which successive arc-like cambia arise outside those of the previous season, forming flanges or rope-like structures on the roots (‘cord roots’, Pate et al. 1989). Most have the small yellow and red flowers typical of the tribes Bossiaeeae (Bentham 1865: 440) Hutchinson (1964: 347) and Mirbelieae (Bentham 1837b: 35) Polhill & Crisp (1982: 55), apparently specialised for bee-pollination, but a few (D. cunderdin, D. epiphyllum and D. speciosa) have enlarged, modified red flowers probably pollinated by birds (Crisp 1994, Toon et al. 2014). Species are found throughout the Australian continent and Tasmania but nowhere else, not even in New Guinea; however, more than 70% are restricted to south-west Western Australia. All are found either in eucalypt- dominated communities (sclerophyll forest, woodland or mallee) or in heathland. In south-west Western Australia, the heathlands and mallee-heaths are known by the indigenous name ‘kwongan’ (Pate & Beard 1984). Most are probably ecologically important nitrogen-fixers. Eighteen species have been tested and all were found to engage in symbiotic N2-fixation with bacterial N2-fixing symbionts (nodulation) (Werner et al. 2014a, 2014b). These 18 species are scattered across the phylogenetic breadth of the genus, being found in eight of the 12 non-nested informally named clades (Fig. 1), so nitrogen-fixing nodulation is likely to occur genus-wide. In eastern Australia, a few species in the D. latifolia group (Crisp 1991a) are dominant in forest understorey, especially when fire is reasonably frequent. Many species are restricted endemics and the genus appears informative about the historical biogeography and diversification of floristic regions within the Australian continent (Cook et al. 2015). This monograph is the culmination of a series of papers by us that have progressively revised Daviesia and is the first complete account of the genus since Bentham (1864). When this study commenced in 1975, about 70 named species were recognised (e.g. Polhill 1981), but that number is now nearly doubled, mainly as a result of the discovery of many restricted endemics in south-west Western Australia. We have conducted extensive field work throughout Australia over four decades and have thereby studied and sampled every taxon described herein. Several taxonomic papers and flora treatments have been published to date in this revisionary series (Crisp 1980a, 1980b, 1982a, 1982b, 1984, 1986, 1987a, 1987b, 1990, 1991a, 1981b, 1992, 1995, Chandler & Crisp 1997, Crisp & Chandler 1997, Chandler & Crisp 1998, Crisp 2002). A molecular phylogeny (described in the next section) A MONOGRAPH OF DAVIESIA Phytotaxa 300 (1) © 2017 Magnolia Press • 3 forms the basis of an informal classification under which the descriptions of the species are arranged. There are also a key to all species and subspecies, sources of online geographic distribution maps, discussions of species’ affinities and complete nomenclatural details including typification. A small number of taxa are described as new or changed in status. Phylogeny and Classification Background:—Daviesia was first described by Smith (1798) based on early collections from Port Jackson (New South Wales) by surgeon J. White. Subsequently, Smith (1808a, 1808b) described several species based on White’s specimens, as well as a couple from King George Sound (Western Australia) using collections by Archibald Menzies. Brown (1811) described two new species from cultivation at Kew gardens. Bentham (1837a) made the first major treatment, as part of a revision of legumes of the world. In this and two publications on Australian taxa (Bentham 1837b, 1864), he described more species in the genus than any other author before the late 20th Century. Moreover, his treatment in Flora Australiensis (Bentham 1864) stands as the most comprehensive revision of the genus to date. Over the next 100 years, more species were described by several authors, but there was no comprehensive treatment or revision. Daviesia has always been accepted as a natural (monophyletic) genus with no controversy about its circumscription. It has been diagnosed primarily by the unique triangular, explosively dehiscing pods, and secondarily by the inflorescence and scleromorphic vegetative parts (e.g. Smith 1805, Brown 1811a, Bentham 1837a). (An expanded morphological diagnosis of the genus is given just before the key to species below.) One or two species have been transferred into or out of the genus, e.g. D. abnormis was previously included in Latrobea Meisner (1848: 219), but these have been the result of errors rather than doubt about the definition of the genus. Monophyly of Daviesia has been supported strongly by phylogenetic analysis. A cladistic parsimony analysis using morphological characters scored for 55 species in the genus (Pate et al. 1989) included three closely related genera as outgroups, namely Viminaria Smith (1805: 507), Erichsenia Hemsley (1905: t. 2777) and Sphaerolobium Smith (1805: 509). Monophyly of Daviesia was supported by synapomorphies in pod shape, phyllodinous seedling leaves and red deposits in the calyx tissue (the last character is reversed within the genus). However, the test of monophyly was weak because few outgroups were used. Subsequent