JOURNAL of the ADELAIDE BOTANIC GARDENS AN OPEN ACCESS JOURNAL FOR AUSTRALIAN SYSTEMATIC BOTANY flora.sa.gov.au/jabg Published by the STATE HERBARIUM OF SOUTH AUSTRALIA on behalf of the BOARD OF THE BOTANIC GARDENS AND STATE HERBARIUM © Board of the Botanic Gardens and State Herbarium, Adelaide, South Australia © Department of Environment, Water and Natural Resources, Government of South Australia All rights reserved State Herbarium of South Australia PO Box 2732 Kent Town SA 5071 Australia J. Adelaide Bot. Gard. 6(3): 207-348 (1984) A TAXONOMIC REVISION OF PROSTANTHERALABILL. SECTION KLANDERIA (F.v. MUELL.) BENTH. (LABIATAE) Barry J. Conn National Herbarium of Victoria, Birdwood Avenue, South Yarra, Victoria 3141 Abstract A taxonomic revision of Prostanthera section Klanderia is presented. General chapterson taxonomic history, morphology, pollination, and breeding systems precede the systematictreatment. Fifteen species are recognized of which eight are described for the first time. Thenew species are P. florifera, P. incurvata, P. laricoides, P. monticola, P. patens, P. pedicellata, P. porcata and P. semiteres. Twosubspecies of P. serpyllifolla and two subspecies of P. semiteres are recognized. P. semiteresspp. intricata is described for the first time. Keys to the species and subspecies are provided. All recognized taxaare provided with full descriptions, distribution information (including maps), ecological and other relevantnotes. All species are illustrated. Morphological variation of P. aspalathoides, the P. calycina-P. microphylla-P.serpyllifolia complex, and the P. laricoides complex, plus the volatile leaf oil variation of P.aspalathoides, were investigated using the multivariate numerical techniques: canonical variate analysis, principalcomponents and principal factor analyses, principal coordinates analysis, surface trend analysis (contour mapping)and differential systematics. Patterns of variation appeared to be associated with environmental andhistorical factors in P. aspalathoides and in the P. calycina-P. microphylla-P. serpyllifolia complex. Thedistinctness of the Kangaroo Island populations appears to reflect the relatively long separation of this island fromthe mainland. Contents Abstract 207 Introduction 208 Taxonomic history 210 Methods, materials and presentation 211 Selected morphological characters 212 Habit 212 Indumentum 213 Leaves 214 Inflorescence 214 Prophylls 218 Calyx 218 Corolla 218 Androecium 219 Disc and gynoecium 219 Fruits and seeds 220 Pollination and floral biology 220 Introduction 220 Field observations 221 Pollination mechanism in section Klanderia 221 Pollination mechanism in section Prostanthera 222 Floral biology and ornithology in section Klanderia 222 Breeding system in section laanderia 223 Seed dispersal and seedling establishment 224 Propagation of section Klanderia 224 Numerical analysis 224 Introduction 224 Selection of morphological characters 225 Pie-numerical analysis 225 Method used to select morphological characters 226 Evaluation of character set 228 Numerical analyses of specimens 231 Numerical analysis of Prostanthera aspalathoides 237 207 B. J. Conn J. Adelaide Bot. Gard. 6(3) (1984) Numerical analysis of the Prostanthera calycina-P. microphylla-P. serpyllifolia complex ..... .....239 Numerical analysis of the Prostanthera laricoides complex 243 Geograpluc vanation 245 Morphological variation in Prostanthera aspalathoides 247 Morphological variation in the Prostanthera calycina-P. microphylla-P. serpyllifolia complex 254 Morphological variation in the Prostanthera laricoides complex 263 Conclusion from geographic variation studies 269 Volatile oils (terpenoids) 271 Materials and methods 271 Numerical analyses of volatile leaf-oils of Prostanthera aspalathoides 273 Evaluation of volatile leaf-oil character set 274 Numerical analyses of specimens 277 Geographic variation of Prostanthera aspalathoides based on volatile leaf-oils 278 Function of volatile oils in Prostanthera 284 Volatile oils as a defence against animals and insects 284 Volatile oils and pollination 285 Systematic treatment 285 a. Prostanthera sect. Prostanthera 286 b. Prostanthera Labill. sect. Klanderia 286 Recognized taxa and their distribution 286 Key to species 288 [Species descriptions] 289 Nomen sedis incertae 341 Acknowledgements 342 References 342 Index to scientific names See index to volume , Introduction Prostanthera species are evergreen sub-shrubs, shrubs or small trees (P. lasianthos) with decussate leaves, racemiform inflorescences, two-lobed calyces, four fertile two-celled anthers in each flower, terminal styles, and fruits composed of four mericarps. Prostanthera, with Eichlerago, Hemiandra, Hemigenia, Microcorys, Westringia and Wrixonia are grouped together in the subfamily Prostantheroideae of the Labiatae (Briquet 1895; Melchior 1964; Carrick 1976, 1977). Carrick (1977) offered a diagnosis for Prostantheroideae. His early paper (Carrick 1976) summarizes the key differences between all the genera in the subfamily (with the exception of Eichlerago which was not described at that time). The results from the work of Sharma & Singh (1982) on carpe! morphology (refer pp. 219 & 220) require Carrick's diagnosis of the Pro stantheroideae to be modified to: Stamens 4 or only 2 (adaxial or abaxial pair sterile); style terminal (may superficially appear subgynobasic); fruit of 4 separate mericarps or entire, dry and indehiscent (Eichlerago). Comment on generic delimitations within the Prostantheroideae must await critical evaluation which is beyond the scope of this present study. The Prostantheroideae are endemic to Australia with the most disjunct distribution being recorded by Jacobs & Pickard (1981) for Westringia fruticosa which they list as occurring on Lord Howe Island. Furthermore, this subfaxnlly is the only one (of the Labiatae) in which any genus is endemic to Australia (Jessop 1980). The Prostantheroideae appear to be a distinct taxon of the Labiatae. This is indirectly verified by the fact that the Prostantheroideae, as circumscribed by Bentham [as `Tribus VII. Prostanthereae.' (Bentham 1834, p. 447); and Bentham & Hooker 18761, has been maintained almost unaltered by subsequentauthors. Cunningham recognized the homogeneity and distinctness of the group of genera which are now classified within this subfatnily as early as 1825 (Cunningham, in Field 1825). However, prior to 1834 the genera which are now regarded as belonging to the Prostantheroideae were frequently placed in separate infra- familial groups (e.g. Reichenbach 1828; Bentham, in Lindley 1829-1830; Bartling 1830). Without evaluating the relationship between the subfamilies of the Labiatae, workers have 208 J. Adelaide Bot. Gard. 6(3) (1984) Prostanthera section Klanderia usually regarded the Prostantheroideae as Most closely related to the Ajugoideae (e.g. Briquet 1895; Hinson 1959). The Prostantheroideae, together with the Ajugoideae and Rosmarinoideae,are regarded as transitional subfamilies between the remaining Labiatae and Verbenaceae (Cronquist 1981). The relationship between these two families and the general affinities of the Lamiales are discussed by several authors (Cantino 1982; Carrick 1977; Cronquist 1981; Munir 1978 and Thorne 1976). During preliminary non-numerical taxonomic and ecological studies of Prostanthera section Klanderia, several taxonomic problems were recognized. Itwas noted that certain taxa had patterns of character variation which appeared to be very complex. Furthermore, some of these taxa appeared to intergrade such that it was difficult to distinguish between them. The taxa which make up the complexes (P. aspalathoides, P. calycina, P. serpyllifolia and the P. laricoides complex [including synonymsrefer 'Systematic Treatment'])were subsequently examined in detail so that various biometrical analyses could be carriedout in an attempt to simplify and visualize any underlying distributionpattern within these taxa. The results of the various analyses (refer Numerical Analysis')were used to suggest and to test hypotheses related to the relationship between thetaxa. The information Function 1 -6 -4 -2 o 2 1 4 1 11 1 "2 11 o s 11. 11 1 4 1 4 1 2 0 * 4 21 4 1 2 3 2 2 * * 3 2 -2 33 2 2 Fig. I Canonical variate scattergram (function I versus function 2) of the volatile leaf oilsof Prostanthera. 1 = Prostanthera sect. Prostanthera series Racemosae; 2 = Prostanthera sect. Prostanthera series Convexae; 3= Prostanthera sect. Prostanthera series Subconcavae; 4 = Prostanthera sect. Klanderia;= group centroid. 209 B. J. Conn J. Adelaide Bot. Gard. 6(3) (1984) provided then formed a basis for the construction of a taxonomic classification scheme. Other taxa could be evaluated and distinguished using non-numerical taxonomic procedures because they were significantly distinctive. The geographic variation found in P. calycina, P. serpyllifolia and P. laricoides was studied using morphological features as taxonomic characters. In P. aspalathoides the geographic variation was studied using both morphological and volatile leaf oils (terpenoids) as taxonomic characters. The results of these analyses were used to test hypotheses related to the relationship between these taxa and environmental factors. Without undertaldng a critical evaluation of Bentham's infrageneric classification (refer 'Taxonomic History), section Klanderia appears to represent a natural group. As pointed out by Bentham (1870), 'the shape of the corolla is so different from [that of section Prostanthera]... thatthis section might well be