Barry John Conn

Infrageneric phylogeny of Chloantheae (Lamiaceae) based on chloroplast ndhF and nuclear ITS sequence data

The tribe Chloantheae (Prostantheroideae, Lamiaceae) currently consists of over 100 species in nine genera, all of which are endemic to Australia. Generic delimitations were assessed using chloroplast 3′ndhF and nuclear ITS nucleotide sequence data for up to seventy species. Analyses of the two datasets, independently and in combination, used maximum parsimony and Bayesian phylogenetic inference methods. Topologies derived from each marker were broadly congruent, but better resolution and stronger branch support was achieved by combining the datasets. The monophyly of the Chloantheae was confirmed. Brachysola is sister to the rest of the tribe and Chloanthes, Cyanostegia and Dicrastylis (including Mallophora) are monophyletic. Although the species within Dicrastylis were only partially resolved, it appears likely that the current sectional classification of this genus will require revision. A clade containing Newcastelia, Physopsis and Lachnostachys (=Physopsideae) was recovered, but the topology indicates that the current generic circumscriptions need further investigation. A close relationship between Hemiphora elderi, Pityrodia bartlingii and P. uncinata was resolved and reflects their palynological and carpological similarities. The relationship between remaining species of Pityrodia was incompletely resolved.

Molecular phylogeny and systematics of Prostanthera (Lamiaceae)

Abstract. Prostanthera is the largest genus of Lamiaceae in Australia and was last comprehensively revised in 1870. To test the classification, and the homology of the morphological characters on which it is based, we analysed nuclear (ETS) and chloroplast (trnT–F and ndhF–rpl32) sequence data for 71 species of Westringieae (Lamiaceae) in separate and combined datasets by using maximum-parsimony and Bayesian-inference methods. Results supported the monophyly of the Westringieae, but indicated that Prostanthera is paraphyletic with respect to Wrixonia, requiring the latter to be synonymised with the former. Although combinations of datasets provided some degree of infrageneric resolution within Prostanthera sensu lato, none of its sections or series could be recovered unambiguously. Prostanthera section Prostanthera and P. section Klanderia (regarded as entomophilous and ornithophilous, respectively) did not form a sister relationship, and neither could be unequivocally resolved as monophyletic. However, all species of P. section Klanderia nested within P. section Prostanthera raising the possibility that P. section Prostanthera is paraphyletic. Similarly, the phylogeny of Prostanthera based on molecular data could not be reconciled with the morphological definition of the traditionally recognised series. We recommend abandoning Bentham’s series as a means of organising morphological variation within the genus, but acknowledge that it is premature to discard Bentham’s sections. The evolutionary and systematic implications of the lack of congruence between our molecular phylogeny and morphologically defined subgeneric taxa are discussed.

Phylogenetic relationships in Loganieae (Loganiaceae) inferred from nuclear ribosomal and chloroplast DNA sequence data

Abstract. Molecular systematics has clarified the limits of Loganiaceae (Gentianales), the tribal circumscriptions and the phylogenetic relationships within the family. Loganieae includes seven genera; however, generic boundaries remain untested and intergeneric relationships are largely unknown. The chloroplast intron petD and the nuclear ribosomal ETS were sequenced for 37 ingroup accessions, including all genera of Loganieae, to infer generic and infrageneric boundaries and intergeneric relationships within the tribe. Maximum parsimony and Bayesian analyses resolved several strongly supported clades. Mitreola s. str. was placed sister to the rest of Loganieae. The south-western Australian endemic, Mitreola minima B.J.Conn, was placed sister to Mitrasacme, Schizacme and Phyllangium, rendering Mitreola polyphyletic. Mitrasacme, Logania section Logania and L. section Stomandra were each strongly supported as monophyletic, but there was no support for the monophyly of Logania. Geniostoma was paraphyletic with respect to a monophyletic Labordia. It is here recommended that Mitreola minima be afforded generic status and that the three species of Labordia used in the present study be reduced to synonymy of Geniostoma. Additional sampling is needed to clarify the relationship between Logania section Logania and L. section Stomandra and to increase support for intergeneric relationships in Loganieae.

Synopsis of the tribe Chloantheae and new nomenclatural combinations in Pityrodia s.lat. (Lamiaceae)

An overview of the tribe Chloantheae (Lamiaceae) is presented. Nomenclatural changes associated with reinstating Dasymalla Endl. and Quoya Gaudich. as distinct genera from Pityrodia s.lat. are provided. The genus Dasymalla consists of five species previously in Pityrodia, whereas seven species of the latter genus are transferred to Quoya. The circumscription of Hemiphora F.Muell. is expanded to include four species previously included in Pityrodia and Hemiphora lanata (Munir) B.J.Conn & M.J.Henwood is formally recognised as a species, based on Pityrodia exserta (Benth.) Munir var. lanata Munir. The new genus Muniria N.Streiber & B.J.Conn is described and consists of four species occurring in the Northern Territory (Australia) that were previously in Pityrodia. A summary of the diagnostic features of Dasymalla, Hemiphora, Muniria and Quoya is presented. The synapomorphies supporting the genera of ‘Physopsideae’ sensu Munir are described, whereas no synapomorphies for Newcastelia or Physopsis were found in the data. A key distinguishing the genera of the tribe is included.

Morphological evaluation of the Drosera peltata complex (Droseraceae)

Abstract. A phenetic study of morphological characters of the Drosera peltata complex (Droseraceae) supports the recognition of the following taxa: D. peltata from wetlands of south-eastern Australia; D. auriculata from south-eastern Australia and New Zealand; the morphologically variable D. hookeri from south-eastern Australia and northern New Zealand; the widespread D. lunata from southern and South-East Asia, as well as northern and north-eastern Australia; and the new species D. yilgarnensis R.P.Gibson & B.J.Conn is here described, from around granite outcrops of south-western Australia. D. bicolor from south-western Australia is recognised as a distinct species outside of the D. peltata complex. D. insolita, considered until recently as a distinct species, is reduced to synonymy of D. lunata. Phenotypic plasticity, vegetative similarity and fleetingly produced diagnostic floral and seed characters within the complex pose significant challenges in understanding the taxonomy of these taxa.

Great Expectations: Correlations between Pollinator Assemblages and Floral Characters in Lamiaceae

Premise of research. Pollination syndromes are used to infer pollinators from floral attributes when field observations of floral visitors are lacking. Such inferences are often found to be incorrect or too generalized. To investigate the relationship between pollinators and observable differences in a genus of Lamiaceae with flowers that appear ornithophilous and entomophilous, we experimentally quantified floral morphology and pollinator assemblages in a phylogenetic perspective. Methodology. Floral morphology was examined using multivariate analysis of geometric morphometrics (corolla shape described by landmarks), linear dimensions, and nonmetric attributes for 17 species of Prostanthera. Pollination effectiveness was determined through censuses of floral visitors and interactions by pollinators with flowers, and multivariate statistics were used to examine correspondence between these data and nonlandmark characters. Ancestral state reconstruction was performed using geometric morphometric data and a phylogenetic tree. Pivotal results. Three floral morphologies were identified in Prostanthera, each of which was associated with a unique pollinator assemblage and corroborated by our detailed field observations. A higher abundance of bees visited flowers with the ancestral (bee) floral type, which had a long corolla, porrect adaxial lobes, and long anther appendages. Visits by birds were more frequent to the derived bird floral type, characterized by red or green flowers with larger nectar volumes, longer and narrower corollas, and a reflexed abaxial lobe. Another derived lineage attracted a higher abundance of generalist flies and beetles (beetle+fly floral type). This lineage had flowers with a shorter corolla tube, reflexed adaxial lobes, and shorter anther appendages. Conclusions. When pollinator frequency was used as a proxy for pollinator effectiveness, the correspondence between the floral types and pollinator assemblages supported traditional concepts of bird and insect pollination syndromes. Intermediates between these floral types also corresponded with phylogenetic position and pollinator assemblage. Linear measurements of floral attributes were just as reliable as landmark data in predicting pollinator assemblages. By combining a molecular phylogeny with the above data, evidence indicated that the bird and beetle+fly floral types diversified from an ancestral bee floral type, demonstrating at least one evolutionary specialization for birds, as well as another shift toward a more generalized pollination syndrome. This combination of techniques presents a potential application with which to investigate the evolution of pollination.

Re-straightening the story of Streblus brunonianus and S. pendulinus (Moraceae)

The current broad-species concept applied to Streblus pendulinus (Endl.) F.Muell. is regarded as not useful taxonomically, and so the narrower, original circumscription is applied here to refer only to the plants restricted to Norfolk Island. The plants previously referred to as S. pendulinus in the Mariana Islands, Micronesia, Papua New Guinea, Australia, New Caledonia, south-western and southern Pacific, and Hawai′i are treated as the widespread S. brunonianus (Endl.) F.Muell. Comparative morphological characters for distinguishing these two species are discussed.

Molecular systematics and biogeography of Logania R.Br. (Loganiaceae).

The angiosperm genus Logania R.Br. (Loganiaceae) is endemic to the mainland of Australia. A recent genetic study challenged the monophyly of Logania, suggesting that its two sections, Logania sect. Logania and Logania sect. Stomandra, do not group together. Additionally, the genus has a disjunct distribution, with a gap at the Nullarbor Plain in southern Australia. Therefore, Logania is a favourable candidate to gain insight into phylogenetic relationships and how these might intersect with Earth-history events. Our phylogenetic analyses of DNA sequences of two chloroplast markers (petD and rps16) showed that Logania sect. Logania and L. sect. Stomandra were each resolved as monophyletic, but the genus (as currently circumscribed) was not. Based on our Bayesian estimates of divergence times, the disjunct distributions within Logania sect. Stomandra could have been caused by flooding of the Eucla Basin. However, this biogeographical process cannot account for the distribution of Logania sect. Logania, with long-distance dispersal and establishment seeming more likely.