Paul J.M. Maas

Phylogeny and evolution of Burmanniaceae (Dioscoreales) based on nuclear and mitochondrial data

The mycoheterotrophic Burmanniaceae are one of the three families currently recognized in the order Dioscoreales. Phylogenetic inference using nucleotide sequences of the nuclear 18S rDNA region and the mitochondrial nad1 b-c intron revealed two well-supported, major lineages within the family, corresponding to the two tribes recognized in the family: Burmannieae and Thismieae. All data supported a strong relationship between Thismieae and Tacca (Dioscoreaceae) making both Burmanniaceae and Dioscoreaceae polyphyletic. The three largest Burmanniaceae genera, Burmannia, Gymnosiphon, and Thismia, are paraphyletic. The splitting of Burmanniaceae into Burmannieae and Thismieae indicates two independent origins of mycoheterotrophy and correlated loss of chlorophyll in Dioscoreales. In the genus Burmannia, in which many species still contain chlorophyll, the achlorophyllous species are nested in between the autotrophic species, suggesting many independent changes from autotrophy to heterotrophy or vice versa. A Bayesian relative rates test on the 18S rDNA data showed considerable variation in substitution rates among Burmanniaceae. The substitution rates in all Thismieae and many Burmannieae are significantly faster than in Dioscoreaceae, but there seems to be no correlation between rate increases and the loss of photosynthesis.

Taxonomy and Classification

This chapter provides a description of all plant families and genera that include putative fully mycoheterotrophic species, excluding initial and partial mycoheterotrophs. The overview covers a total of 17 families, 101 genera, and ca. 880 species. For each family and genus (except for Orchidaceae) a short morphological description is provided followed by notes on taxonomy, distribution, evolution, and ecology. For most genera a line drawing of a representative species is provided. Included families are: Aneuraceae, Burmanniaceae, Corsiaceae, Ericaceae, Gentianaceae, Gleicheniaceae, Iridaceae, Lycopodiaceae, Ophioglossaceae, Orchidaceae, Petrosaviaceae, Podocarpaceae, Polygalaceae, Psilotaceae, Schizaeaceae, Thismiaceae, and Triuridaceae.

Classification of a large and widespread genus of Neotropical trees, Guatteria (Annonaceae) and its three satellite genera Guatteriella, Guatteriopsis and Heteropetalum

A phylogenetic study of the genus Polycarpon was made using DNA sequence data from the chloroplast rpsl6 intron and nuclear RPB2 regions. Polycarpon as currently recognised is shown to be polyphyletic. The South American species P. coquimbense and P. suffruticosum are more closely related to Haya obovata (Socotra) and Polycarpaea spicata (paleotropical) than to the remaining species of Polycarpon, and the widespread tropical species P. prostratum is nested with Macaronesian species of Polycarpaea. All three should therefore be excluded from Polycarpon. The remaining species, the P. tetraphyllum group, has its main diversity in the Mediterranean region. It is a polyploid complex with morphologically very similar taxa mostly separated only by partially overlapping characters. The members of this group form a strongly supported, but largely unresolved clade. It is proposed that they are all included in a widely circumscribed P. tetraphyllum. The dehiscence of the capsules in P. tetraphyllum, by valves that elastically roll inwards and finally throw out the seeds, is unique in Caryophyllaceae and provides a strong synapomorphy for Polycarpon in this new restricted sense.

Revision of the Neotropical generaBocageopsis, Onychopetalum, and Unonopsis (Annonaceae)

(Annonaceae). The closeness of these three genera was expressed by Fries when he placed them in his (informal) Unonopsis group (Fries, 1959), and the close relationship is supported by more recent phylogenetic research as well. Four species are recognized in Bocageopsis and two species in Onychopetalum. Unonopsis is by far the largest of the three genera with close to 50 species, of which no less than 23 species are here described as new. One species (Unonopsis umbilicata) had to be shelved as insufficiently known for lack of data, and another, obviously new, species from Colombia is too incomplete and is described provisionally as Unonopsis spec. A. Several keys are provided, one for the genera and one each for the species of Bocageopsis and Onychopetalum. For the species of Unonopsis a key to all species and, in addition, a key to the species of Mexico and Central America are provided. The species treatments include full descriptions, geographical and ecological notes, distribution maps, synonymy, taxonomic notes, and vernacular names. A complete list of exsiccatae is appended. Parallel to the taxonomic revision, a leaf anatomical survey was made by E.-J. van Marle, and is included here.

Studies in Annonaceae XXXVI. The Duguetia alliance: where the ways part.

Results of a cladistic analysis of morphological and anatomical data of the Duguetia alliance (Annonaceae) are presented. Several novel characters, or characters so far not incorporated into phylogenetic analyses, are used. Parsimony analysis resulted in two strongly supported clades: a Fusaea clade, comprising Fusaea, Duckeanthus, Letestudoxa, and Pseudartabotrys, and a Duguetia clade, comprising all Neotropical and African species of Duguetia. Support for the past distinction of Pachypodanthium from Duguetia appears to be absent. Characters used to resolve relationships between and within the two clades are difficult to polarize by outgroup comparison. It is demonstrated that the critical reassessment of classical morphological characters, and the search for new ones, may well advance phylogenetic resolution within Annonaceae

Increasing diversity in the species-rich genus Guatteria (Annonaceae)

During a taxonomic treatment of Annonaceae for the Flora of the Guianas project, an unusual new species of Guatteria Ruiz & Pav., G. anteridifera from French Guiana and Amapa in Brazil (Northern South America) was found and described herein.

Studies in Annonaceae. XIII, The role of morphological characters in subsequent classifications of Annonaceae : a comparative survey

A comparative survey of several historical classifications of Annonaceae down to the subtribal level is given. The role of various key characters is briefly discussed. The present paper at the same time may be considered as an introductory paper to forthcoming publications of general studies on flower and fruit characters now being conducted at Utrecht.

Plants of the Annonaceae traditionally used as antimalarials: a review

Especies da familia Annonaceae tem amplo uso na medicina tradicional em regioes tropicais para o tratamento da malaria e de sintomas como febres, dentre outras doencas. Estudos fitoquimicos desta familia tem revelado componentes quimicos que podem oferecer novas alternativas para o tratamento e controle da malaria. Buscas em sites de referencia cientifica (SciFinder Scholar, Scielo, PubMed, ScienceDirect e ISI Web of Science) e uma pesquisa bibliografica na literatura por especies da familia Annonaceae utilizadas tradicionalmente para tratar a malaria e febre foram realizadas. Esta familia contem 2.100 especies em 123 generos. Encontramos 113 registros que relatam o uso de 63 especies de 27 generos utilizadas como antimalaricos e febrifugas. Mesmo que as mesmas especies de Annonaceae sejam utilizadas por diversos grupos etnicos, frequentemente diferentes partes da planta sao escolhidas para o uso e diversos metodos de preparacao e de tratamento sao utilizados. Os extratos etanolicos de Polyalthia debilis e Xylopia aromatica sao comprovadamente bastante ativos contra Plasmodium falciparum in vitro (concentracao de inibicao media, IC50 < 1,5 µg/mL). Injecao intraperitoneal de extratos aquosos de Annickia chlorantha (especie citada Enantia chlorantha) eliminou Plasmodium yoelii nigeriensis cloroquino-resistente do sangue de camundongos de maneira dose-dependente. Mais perfis fitoquimicos de especies de Annonaceae sao necessarios, especialmente informacoes sobre as substâncias antimalaricas mais comumente distribuidos nesta familia.

Revision of the Neotropical genus Pseudoxandra (Annonaceae)

A taxonomic revision is made of the Neotropical genus Pseudoxandra. This genus forms part of the Cremastosperma alliance which consists of Bocageopsis, Cremastosperma, Ephedranthus, Klarobelia, Malmea, Mosannona, Onychopetalum, Oxandra, Pseudephedranthus, Pseudomalmea, Pseudoxandra, Ruizodendron, and Unonopsis, all from the Neotropics. Within Pseudoxandra 22 species are recognized, four of which were described quite recently by the first author (Maas et al., 1986). Fourteen species are described here as new. Two dichotomous keys are provided, one for the genera of the Cremastosperma alliance, and the other for the species of Pseudoxandra. The species treatments include descriptions, geographical and ecological notes, distribution maps, synonymy, taxonomic notes, and vernacular names. A complete index of exsiccatae is included. Parallel to the taxonomic revision, a leaf anatomical survey was made by E.-J. van Marle. One of the intriguing features in Pseudoxandra is the frequent presence of minuscule warts on the leaves in dried specimens, while fresh material does not show any such warts. Osteosclereids found in the mesophyll of most species are probably responsible for this feature. This revision is meant as a precursor for a future Flora Neotropica treatment of the integral Cremastosperma alliance. Revisions of Klarobelia, Malmea s.s., Mosannona and Pseudomalmea, once constituting the genus Malmea s.l., were published earlier by Chatrou (1998). Treatments of other genera are under way, or planned for the near future.

A new species of Pseudoxandra (Annonaceae)

A new species, as an addition to the revision of the genus Pseudoxandra by Maas & Westra (2003), is described.