Muelleria 17, 2003
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Muelleria 17: 19–135 (2003) Notes on Boronia (Rutaceae) in eastern and northern Australia Marco F. Duretto National Herbarium of Victoria, Royal Botanic Gardens Melbourne, South Yarra, Vic. 3141 present address: Tasmanian Herbarium, GPO Box 252-04, Hobart, Tas. 7001 Abstract Boronia Sm. sections Boronia and Cyanothamnus (Lindl.) F.Muell. are revised for South Australia, Queensland, New South Wales, Victoria and Tasmania with the exception of B. anemonifolia A.Cunn., B. coerulescens F.Muell., B. inornata Turcz. and B. rigens Cheel. Twenty-one taxa are described as new, these being B. barkeriana F.Muell. subsp. angustifolia Duretto, B. barkeriana subsp. gymnopetala Duretto, B. citriodora Gunn ex Hook.f. subsp. orientalis Duretto, B. citriodora subsp. paulwilsonii Duretto, B. deanei Maiden & Betche subsp. acutifolia Duretto, B. elisabethiae Duretto, B. hemichiton Duretto, B. hippopala Duretto, B. imlayensis Duretto, B. inflexa Duretto,B. inflexa subsp. grandiflora Duretto, B. inflexa subsp. montiazura Duretto, B. inflexa subsp. torringtonensis Duretto, B. montimulliganensis Duretto, B. occidentalis Duretto, B. pilosa Labill. subsp. parvidaemonis Duretto, B. pilosa subsp. tasmanensis Duretto, B. pilosa subsp. torquata Duretto, B. rozefeldsii Duretto, B. warangensis Duretto, and B. yarromerensis Duretto. Boronia gunnii Hook.f. is reinstated and taxa are lectotypified where necessary. Within B. section Valvatae (Benth.) Engl., B. beeronensis Duretto, B. grimshawii Duretto, and B. gravicocca Duretto are newly described and types are identified for B. keysii Domin, B. ledifolia var. repanda F.Muell. ex Domin, B. rosmarinifolia A.Cunn. ex Endl. and B. rubiginosa Endl. Keys are provided for all taxa. The two fossil taxa, B. harrisii Ett. and B. hookeri Ett., are also discussed. Introduction Boronia Sm. was subjected to a cladistic analysis by Weston et al. (1984) who demonstrated that B. sections Boronia, Cyanothamnus (Lindl.) F.Muell. and Valvatae (Benth.) Engl. are monophyletic, the former only by the inclusion of a number of other sections and series (see taxonomy). Subsequently a new classification for B. section Boronia was proposed by Wilson (1998) which included two series, viz. B. series Boronia and series Pedunculatae Benth. Wilson (1998) revised those species of B. sections Boronia and Cyanothamnus that are found in Western Australia including B. coerulescens F.Muell. (section Cyanothamnus) and B. inornata Turcz. (series Boronia), both of which extend to the eastern states. He also discussed B. section Imbricatae Engl., the sole member of which, B. cymosa Engl., is restricted to south-western Western Australia. Two other eastern Australian species of B. section Cyanothamnus, B. anemonifolia A.Cunn. and B. rigens Cheel, were revised by Neish and Duretto (2000). Here, the remaining eastern representatives of B. sections Boronia and Cyanothamnus are revised. Boronia sections Valvatae, Algidae Duretto and Alatae Duretto were subjected to a cladistic analysis by Duretto and Ladiges (1999) and revised by Duretto (1999b). Since these publications, new material has come to light including previously unseen type material as well as specimens of three undescribed species. This material is discussed below. Materials and Methods Material: Herbarium specimens were made available from AD, BRI, CANB, DNA, HO, LD, MEL, NE, NSW, PERTH, PR, QRS, and TCD. Cibachromes of specimens at K, colour transparencies of specimens at BM and CGE, and photographs of specimens at 20 M. F. Duretto LINN, LIV and W have been seen. Herbarium abbreviations follow Holmgren et al. (1990). These specimens were augmented with material collected in the field from 1992 to 2002. Where possible, at least five plants per local site were sampled. Leaf Anatomy: The central portion of the leaves or leaflets were sectioned transversely. Fresh material was fixed in 70% ethanol when collected. Most material was dehydrated through a graded ethanol series up to 100% ethanol, infiltrated with 100% LR-White (London Resin) through a resin/ethanol series, and polymerised at 60°C. Sections 2 µm in thickness were cut on a Reichert Ultracut ultra-microtome and stained with 0.05% toluidine blue solution (pH 4.4). Some material was sectioned by hand. Voucher specimens for leaf anatomy are listed in Appendix 1. Scanning Electron Microscopy: Seed surfaces of a representative sample of taxa were surveyed using scanning electron microscopy. Material was mounted on stubs using double sided or carbon tape with conductive carbon paint, coated with gold using an Edwards Sputter Coater S150B and examined and photographed at 5KV using a JEOL 840 Scanning Electron Microscope equipped with a lanthanum hexaboride filament. Cladistic analysis of Boronia section Valvatae: To determine the phylogenetic positions of three new species of the section described herein, these species were scored for the data set of B. section Valvatae sensu lato that was analysed by Duretto and Ladiges (1999). All taxa and characters of that analysis were used following the methods as outlined for their third analysis. Additional characters (56 young branches, 0-not glandular tuberculate, 1-glandular tuberculate; 57 leaves, 0-not obviously glandular, 1- obviously glandular) were added. The data set was analysed using PAUP 4.03ba (Swofford 2000) and B. section Alatae, B. section Algidae and B. subsection Ternatae Duretto were used as outgroups. Taxon Descriptions and Distributional Information: Descriptive terminology follows Hewson (1988) for hairs, and Briggs and Johnson (1979) and Weston (1990) for inflorescence structure. Conservation or ROTAP codes follow the format of Briggs and Leigh (1996) for all taxa. Acronyms for botanical divisions of New South Wales follow Harden (1990). Taxonomy Boronia Sm., Tracts nat. hist., 288 (1798). Lectotype species: B. pinnata Sm. fide Wilson, Nuytsia 12: 121 (1998). Shrubs or rarely small trees or herbs, usually erect and many branched, variously indumented with simple and/or stellate hairs. Branches terete to quadrangular, unarmed. Leaves opposite decussate or rarely subopposite or whorled, simple or imparipinnate or bipinnate or tripinnate, 1–21(–53)-foliolate; lateral leaflets opposite or rarely subopposite. Inflorescence terminal and/or axillary, cymose or paniculate or flower solitary. Flowers bisexual, four-merous, rarely five-merous. Sepals free. Petals free, usually pink or white, sometimes blue or green or yellow or brown. Stamens usually 8, rarely 4, 4–8 fertile, filaments erect, anthers versatile. Carpels +/- free, lacking sterile apex; styles usually fused, arising terminally or subterminally from ovary; ovules two per carpel, usually only one reaching maturity. Fruit of 1–4 cocci; cocci not transversely ridged, with rounded apices. Seed released explosively with elastic endocarp, shiny or dull, black or grey or rarely brown. World c. 149 spp., endemic to Australia, present in all states and mainland territories. The genus was named to honour Francesco (Francis) Borone (1769–1794), a young Italian naturalist who had impressed Smith with his enthusiasm and ability (Smith 1798). The cytoevolution of Boronia has been reviewed by Smith-White (1954) and Stace et al. (1993), the foliar sclereids by Rao and Bhattacharya (1978, 1981), phytochemistry by Ghisalberti (1997), and horticultural forms by Elliot and Jones (1982), Plummer and Payne (1997) and Spencer (2002, for south-eastern Australia). Boronia series Boronia, B. Notes on Boronia 21 series Pedunculatae and B. section Cyanothamnus each have distinctive seed morphology which is discussed and illustrated by Wilson (1998). “All the species of Boronia are more or less interesting, and attract attention from the neatness of growth, and their pretty pink blossoms. Their dwarf habit and compactness peculiarly fit them for glasshouse culture, and for growing in pots; as they can be placed on any kind of stage, and will, if judiciously treated, bear to be exposed to view on all sides.” Paxton (1841, p. 123). Fossils of Boronia Two species of fossil Boronia, B. harrisii Ett. and B. hookeri Ett. (types lodged at the Australian Museum and Geological Survey of NSW), were described and illustrated by Ettingshausen (1888). The material originated from sub-basaltic deposits of the late Eocene (c. 30 MY ago) in the Emmaville area of northern New South Wales (Pickett et al. 1990). Both species are based on leaf fragments, and neither specimen, in particular B. hookeri, can be placed confidently in Boronia (pers. obs.). Problems with Ettingshausen’s identifications have been discussed by Hill (1988a, b). Boronia hookeri is a pinnate leaved taxon with leaves similar to that of B. angustifolia Duretto, B. amabilis S.T.Blake and B. rubiginosa Endl. (all B. section Valvatae) which are found in northern New South Wales or nearby in south-east Queensland (see Duretto 1999b). The leaves could just as easily belong to a number of small, pinnate leaved taxa of other families. Boronia harrisii appears to be made up of a short twig with simple leaves. The leaves are obovate with serrate margins. Ettingshausen (1888) considered B. harrisii was intermediate between B. serrulata Sm. (see discussion below) and B. crenulata Sm. (a Western Australian taxon). Superficially the leaves are similar to those of B. serrulata or the juvenile leaves of B. microphylla Sieber ex Rchb. (see below). Boronia serrulata is restricted to the Sydney sandstones and B. microphylla is found from the Granite Belt of Queensland and New South Wales (including the Emmaville area)