Karen L. Wilson

Using matK sequence data to unravel the phylogeny of Casuarinaceae

Casuarinaceae are a Gondwanic family with a unique combination of morphological characters not comparable to any other family. Until recently, the 96 species in the family were classified in a single genus, Casuarina s.l. A recent morphological revision of the family resulted in the splitting of Casuarina s.l. into four genera-Allocasuarina, Casuarina s.s., Ceuthostoma, and Gymnostoma. This study uses matK sequence data from 76 species of Casuarinaceae and eight outgroup taxa to examine the phylogenetic structure within the Casuarinaceae. The study demonstrates the monophyly of the four genera and examines the relationships within the family; it tests the validity of the infra-generic subdivision of Allocasuarina; it discovers geography-based infra-generic subdivisions within Gymnostoma and Casuarina; and, finally, provides a molecular framework on which to trace the evolution of xeromorphy in the Casuarinaceae.

Flavonoids in leaves and inflorescences of australian Cyperus species

Abstract A survey of the flavonoids of some 92 species of Australian Cyperus , mainly of subtropical or tropical origin, has confirmed a correlation previously reported in this family between flavonoid pattern and plant geography. The pattern found was similar to that of African and South American Cyperaceae, particularly in the occurrence of the rare marker substance, luteolin 5-methyl ether. Tricin and luteolin are relatively common, in glycosidic form, in the leaves while the flavonol quercetin is infrequent. When present, quercetin occurs either in glycosidic form or free as a methyl ether. The 3-monomethyl and 3, 7-dimethyl ethers of kaempferol and quercetin and the 3, 7, ‴-trimethyl ether of quercetin are reported for the first time from the Cyperaceae. The flavonoid pattern of inflorescences is distinct from that of the leaves in that tricin is not detectable and that luteolin 5-methyl ether appears to be replaced by 7, 3′, 4′-trihydroxyflavone. In addition, the aurone aureusidin is more commonly present than in the leaves and is occasionally accompanied by two further aurones. The glycoxanthones mangiferin and isomangiferin occur rarely in all three species examined in the section Haspani , i.e. in C. haspan , C. prolifer and C. tenuispica . In general, however, the flavonoid data do not offer any markers which separate off different sections within the genus; there are, however, some significant correlations between the frequency of the flavonoid classes and subgeneric groupings.

Flavonoids in leaves and inflorescences of australian cyperaceae

Abstract A survey of 170 Australian species of Cyperaceae belonging to 35 genera has confirmed that this family has a highly characteristic flavonoid pattern in leaf and inflorescence. Aurone pigments, the most distinctive family constituents, were found in the leaves of 25% of the sample and in the inflorescences of 40%. Sulphuretin was found for the first time in the family, in Carex appressa . Flavones, such as tricin and luteolin, are very common; in addition, a variety of methyl ethers were detected. Luteolin 5-methyl ether was found in further genera, while luteolin 7-methyl ether, diosmetin and acacetin were detected for the first time in the Cyperaceae. Flavonols and their methyl ethers occurred in over one-third of the species, particularly in the leaves, being especially well represented in the genera Fuirena, Gahnia, Lepidosperma and Mesomelaena . Myricetin was found only twice, in two Baumea species. The 3-desoxyanthocyanidin carexidin was found in the inflorescences of eight species, i.e. in 5% of the sample. Taxonomically, the results are mainly of interest at the generic and specific level, where the patterns sometimes show useful correlations with morphology. At the tribal level, the Sclerieae are the most distinctive, with higher than average frequency of flavone C -glycosides, flavonols, proanthocyanidins and aurones, and lower than average frequency of flavones.

Flower or spikelet? Understanding the morphology and development of reproductive structures in Exocarya (Cyperaceae, Mapanioideae, Chrysitricheae).

Fundamental questions of floral morphology remain unresolved in the grasslike monocots in order Poales, including what constitutes a flower and what constitutes a spikelet. The mapaniid sedges have particularly complex spikeletlike structures, variously interpreted as clusters of flowers or spikelets. Recent phylogenetic studies of Cyperaceae have identified the mapaniid clade as sister to the rest of the family, but the homology of mapaniid reproductive units (RUs) and spikeletlike units (SLUs) to other sedge flowers and spikelets is unclear. We examined reproductive development in the mapaniid Exocarya sclerioides. Inflorescence branches terminated in a SLU with bracts and 1-4 RUs. RUs had four small leaflike structures (LLSs): two lateral LLSs, each associated with a stamen, an abaxial LLS associated with a stamen, and an adaxial LLS. The gynoecium terminated the RU. All RUs were axillary to bracts, and unexpanded bracts and RUs were produced beyond expanded RUs, so SLUs were racemose. RUs developed from a single primordium that initiated two lateral LLSs, then two lateral stamens, then the gynoecium. Initiation of the abaxial LLS and stamen and the adaxial LLS followed. We hypothesize that the RU is a sympodial branch that terminates in a hermaphroditic flower with two stamens and a gynoecium; the two lateral LLSs are halves of a deeply divided prophyll.

Megaphylogenetic Specimen-Level Approaches to the Carex (Cyperaceae) Phylogeny Using ITS, ETS, and matK Sequences: Implications for Classification

Abstract We present the first large-scale phylogenetic hypothesis for the genus Carex based on 996 of the 1983 accepted species (50.23%). We used a supermatrix approach using three DNA regions: ETS, ITS and matK. Every concatenated sequence was derived from a single specimen. The topology of our phylogenetic reconstruction largely agreed with previous studies. We also gained new insights into the early divergence structure of the two largest clades, core Carex and Vignea clades, challenging some previous evolutionary hypotheses about inflorescence structure. Most sections were recovered as non-monophyletic. Homoplasy of characters traditionally selected as relevant for classification, historical misunderstanding of how morphology varies across Carex, and regional rather than global views of Carex diversity seem to be the main reasons for the high levels of polyphyly and paraphyly in the current infrageneric classification.

Systematic studies in Lepidosperma (Cyperaceae: Schoeneae) with particular reference to L. laterale

Lepidosperma laterale exhibits much morphological variation across its geographical range. This study included L. laterale, and morphologically similar species, as well as several comparator species. Phenetic analyses based on 27 morphological and 25 vegetative anatomical characteristics were undertaken in an attempt to resolve taxonomic issues within the study group. Evidence for broadening the delimitation of L. laterale is strong as OTUs of this variable species formed a group with indistinct clusters in all analyses. The mixed, diffuse clusters obtained of OTUs of specimens identified as L. gunnii with specimens of L. laterale suggest that the species limits of the former lie within the limits of the latter. Specimens of most other study group taxa formed relatively cohesive, discrete clusters in ordination and cluster analyses. The results provide strong support for recognition of L. sp. Whian Whian S.F. (J. Hodgon 331 & D.M. Hodgon) and L. sp. Mt Coolum (P.R. Sharpe 5605A) as new species.

A review of the genus Lepidosperma Labill. (Cyperaceae: Schoeneae)

Abstract. Species diversity in the genus Lepidosperma Labill. is much greater than previously thought. On the basis of morphological and molecular data, we currently recognise 73 named species (mainly in Australia), with many more species yet to be described. As a precursor to a complete revision, we review the names published in Lepidosperma. All published names at infrageneric, specific and infraspecific rank are typified and their current taxonomic status is indicated. Brief distribution notes are given for the 73 named species recognised. We also give a list of names referrable to other genera. A summary of the taxonomic history of the genus is provided, as well as notes on the specimens collected by early collectors in Australia. Three new combinations are made in Lepidosperma: L. asperatum (Kük.) R.L.Barrett, L. neozelandicum (Kük.) R.L.Barrett & K.L.Wilson and L. rigidulum (Kük.) K.L.Wilson. L. sanguinolentum K.L.Wilson is a nomen novum based on L. drummondii var. floribundum Kük. Lectotypes are designated for eight infrageneric names and for 39 specific and infraspecific names, including the following: L. angustifolium Hook.f., L. angustatum R.Br., L. angustatum var. curvispiculum Benth., L. australe (A.Rich.) Hook.f., L. benthamianum C.B.Clarke, L. brunonianum Nees, L. brunonianum var. binuciferum Kük., L. canescens Boeckeler, L. carphoides Benth., L. concavum var. pyramidatum Benth., L. confine Nees, L. costale Nees, L. costale var. densispicatum Kük., L. drummondii Benth., L. effusum Benth., L. forsythii A.A.Ham., L. gladiatum Labill., L. globosum Labill., L. inops F.Muell. ex Rodway, L. laterale var. angustum Benth., L. laterale var. majus Benth., L. leptophyllum Benth., L. leptostachyum Benth., L. leptostachyum var. asperatum Kük., L. muelleri Boeckeler, L. neesii Kunth, L. perplanum Guillaumin, L. perteres C.B.Clarke, L. pruinosum Kük., L. pruinosum var. rigidulum Kük., L. quadrangulatum A.A.Ham., L. resinosum var. pleianthemum Kük., L. scabrum Nees, L. scabrum var. effusum Benth., L. sieberi Kunth, L. squamatum Labill., L. tenue Benth., L. viscidum R.Br. and L. viscidum var. subpyramidale Kük. Twenty-two excluded names are listed and new combinations are provided in Tricostularia for L. aphyllum R.Br. and L. exsul C.B.Clarke. A lectotype is selected for L. pauciflorum F.Muell. (= Tricostularia pauciflora (F.Muell.) Benth.).

Clarification of the Use of the Terms Perigynium and Utricle in Carex L. (Cyperaceae)

Abstract Despite previous efforts to unify the terminology for Cyperaceae, two different terms, perigynium and utricle, are in common use for the prophyllar bract enclosing the female flower of Carex. Use of these terms is divided largely on geographic lines (mainly North American versus European and other authors, respectively). The recent merging of Kobresia with Carex requires a single term to refer to both the open prophyll of Kobresia and the laterally closed one of Carex. However, even when authors use utricle for Carex species, these same authors do not refer to the open prophyll of Kobresia as a utricle. We show that perigynium was apparently coined earlier than utricle, at the end of the 18th century, but the term utricle became more widespread than perigynium by the 20th century. Neither of the two terms is unambiguous, as both have also been used for other structures in other plant groups. Given this background, we propose revised definitions of both terms based on two facts: 1) the greater semantic accuracy of perigynium to refer to both the prophylls of Carex and the former genus Kobresia; and 2) the greater spread, and thus social utility, of the term utricle. We also discuss the terminology used for the fertile prophylls of lower branching orders found in some Carex groups and recommend use of the terms cladoprophyll, tubular cladoprophyll, and utriculiform cladoprophyll.

Schoenus (Cyperaceae) is not monophyletic based on ITS nrDNA sequence data

Abstract. We used nuclear rDNA-sequence data from the internal transcribed spacer (ITS) region to test the monophyly of Schoenus by using maximum parsimony and Bayesian inference. Schoenus is not monophyletic, with strong bootstrap support for most branches and congruence across analyses. nrITS does not resolve terminal taxa fully and, therefore, needs to be used in combination with other lines of evidence to address questions of species limits.

Phylogeny of Carpha and related genera (Schoeneae, Cyperaceae) inferred from morphological and molecular data

The limits, definitions and relationships of Carpha have been controversial and unclear. This study using cladistic analyses of morphological and combined morphological and molecular data indicates that: (1) Carpha sensu latu is paraphyletic and its species form two clades, consistent with the definitions of Carpha sensu stricto and Asterochaete respectively (i.e. the data support the division of Carpha sensu latu into two genera: Carpha sensu stricto and Asterochaete); (2) the morphological data show a high degree of homoplasy within Schoeneae; (3) Schoeneae is not a monophyletic tribe; (4) Schoenus and Tricostularia are polyphyletic; (5) it is better to place Schoenoides back in Oreobolus; (6) separation of Capeobolus brevicaulis from Costularia or Tetraria is supported; and (7) both genera Costularia and Tetraria should be maintained. The study resolves some phylogenetic relationships between Carpha and its relatives. Many aspects of these relationships are in agreement with previous studies, but some of these relationships have no support. The study also resolves the phylogenetic relationships of species of Carpha, although with lack of support for some clades, highlighting the need for other sources of data.