Homaliodendron decompositum (Brid.) Wagn. reduced to synonymy with H. flabellaturn (Sm.) Fleisch

Abstract

Four small moss families found in Malawi are reviewed, and keys are provided to all taxa known in Malawi (and usually to all known in Africa). Regmatodontaceae is shown to contain only one species in Africa, but both known species are keyed. Rhachitheciaceae, contains three genera in Africa (which are keyed), only one of which occurs in Malawi, and for this genus a key is provided for all three African species. Rhacocarpaceae contains only two species in Africa, which are keyed, only one of which is known from Malawi. Rhizogoniaceae contains two genera and three species in Africa.     

Recent Bryological Literature, 68

Abstract

Five species of Colura are reported from Mulanje Mountain, of which four, C. ealyptrifolia (Hook.) Dum., C. digitalis (Mitten) Steph., C. hattoriana Pócs and C. tenuicornis (Evans) Steph. are new for Malawi. C. hattoriana is also reported new for mainland Africa. A key to sub-Saharan taxa is provided.     

Tropical African cedars (Widdringtonia, Cupressaceae): systematics, ecology and conservation status

Phenetic analyses of 24 morphological characters, collected in the field for 150 trees of Widdringtonia in Malawi, Zimbabwe, Mozambique and northern South Africa, show two distinct clusters. One can be identified as W. whytei , a tall, wide-crowned forest tree endemic to Mt Mulanje in Malawi, while the other is W. nodi/bra , a multi-stemmed shrub or narrow-crowned tree, which is common on Mulanje and widespread in southern Africa. These two sympatric species are distinct on phenetic, phylogenetic, ecological and biological grounds. The distinguishing characters of the two species are analysed and discussed and the differences are related to different responses to fire. Widdringtonia whytei is a forest pioneer with limited fire survival ability, while W. nodiflora coppices after fire and is common in fire-prone heathlands. To date it has been assumed that there is a single species of Widdringtonia on Mt Mulanje, and this has led to faulty management and exploitation decisions. Extensive plantations of the economically useless W. nodiflora have been established, in the belief that they are the economically desirable Mulanje cedar, W. whytei , which is now in danger of extinction.     

British Bryological Society Expedition to Mulanje Mountain,Malawi 3. Erpodiaceae (Musci)

Abstract

Four members of the moss family Erpodiaceae, Aulacopilum trichophyllum, Erpodium beccarii, E. coronatum and E. grossirete, collected during the 1991 British Bryological Society expedition to Mulanje Mountain, are recorded as new for Malawi.     

Neglected refugia of biodiversity: mountainous regions in Mozambique and Malawi yield two novel freshwater crab species (Potamonautidae: Potamonautes)

Phylogenetic relationships amongst the southern African freshwater crab fauna are reinvestigated following the recent collection of morphologically distinct Potamonautes specimens from remote mountainous regions in Malawi and Mozambique. Specimens were subjected to DNA sequencing of three mtDNA loci, cytochrome c oxidase subunit I (COI), 12S rRNA, and 16S rRNA and compared to the 14 described species from the region. Phylogenetic analysis using maximum parsimony and Bayesian inference revealed the presence of two novel evolutionary lineages. The phylogeny demonstrates that Potamonautes obesus (A. Milne‐Edwards, 1868) is sister to a morphologically distinct novel species from Mount Namuli in Mozambique. Two sympatric and genetically distinct species from Mount Mulanje, in Malawi (forms A and B) were recognized. Form B is sister to the large‐bodied South African riverine freshwater crabs and represents a novel lineage whereas the remaining species (form A) from Mulanje, in Malawi was sister to samples from Mounts Inago and Mabu, and in Mozambique was identified as Potamonautes choloensis (Chace, 1953). The two novel evolutionary lineages were genetically distinct and morphologically different from the described species in each of the respective regions. Two new freshwater crab species Potamonautes namuliensis sp. nov. and Potamonautes mulanjeensis sp. nov. , are described in the present study. The samples from Mount Mulanje in Malawi, and Mounts Mabu and Inago in Mozambique represent new distribution records for Potamonautes choloensis. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 164 , 498–509.     

British Bryological Society Expedition to Mulanje Mountain,Malawi 2. Checklist of Malawi bryophytes

Abstract

A checklist of all bryophytes identified from Malawi at May 1991 is presented, with synonyms and references. The list is derived from literature and unpublished collections, and contains 197 mosses and 106 hepatics. The checklist was produced to provide a basis for describing plants new to Malawi, particularly for the British Bryological Society Expedition to Mulanje Mountain, Malawi in 1991. Distribution information is included, and the species accounts include published references and collection numbers where known. All information is held on a computer database.     

British Bryological Society Expedition to Mulanje Mountain,Malawi. 17 Sematophyllaceae (Bryopsida): Part 1

Abstract

The family Sematophyllaceae is a difficult family to treat in Africa because of the large number of species described without any subsequent revision or monography and, despite the many collections mentioned in this paper, only two species had previously been identified from Malawi. A total of four species in four genera (Gammiella, Mρacrohymenium, Radulina and Wijkia) are recorded in this paper, all but one new to Malawi. The two remaining genera (Sematophyllum and Trichosteleum) present additional difficulties of identification, and will be dealt with separately.     

British Bryological Society Expedition to Mulanje Mountain,Malawi 1. Background,itinerary and procedures

Abstract

In June 1991 a nine-man British Bryological Society Expedition collected bryophytes and made ecological observations in many parts of Mulanje Mountain, Malawi. Mulanje Mountain is an isolated member of the Afro-montane archepelago where the rich and distinctive ecosystem is under threat from a range of human activities. Over 4500 specimens were collected and it is clear that they will add many species to the known bryophyte flora of Malawi, as well as providing phytogeographical and ecological data and indicating priority sites for conservation. The present paper, the first in a series reporting the work of the Expedition, describes the objectives, itinerary, logistic arrangements and collecting procedures.     

Kniphofia monticola (Liliaceae), a new species from Malawi

Kniphofia monticola Blackmore sp. nov., from Mulanje Mountain in Malawi is described. This new species is most closely related to K. splendida E. A. Bruce, a widely distributed species in tropical and southern Africa.     

New records of bryophytes from the Canary Islands

Abstract

Two members each of the Adelanthaceae and Schistochilaceae and three of the Porellaceae are recorded from Mulanje Mountain, of which Adelanthus lindenbergianus (Lehm.) Mitt., Porella abyssinica (Nees) Trev. var. hoehnelii (Steph.) Pócs, Porella capensis (Gott.) Mitt. and P. subdentata (Mitt.) Steph. are first records for Malawi.     

The Habitat of Zygodon forsteri (Brid) Mitt. in the New Forest,Hants

Abstract

Seven species are reported here for the first time for South Georgia. Two of these were already known from Tierra del Fuego, Acrolophozia fuegiana Schust. and Marsupella sprucei (Limpr.) H. Bern., but Acrolophozia sulcata Hässel, Marsupella austrogeorgica Hässel, and Marsupella minutula Hässel are described as new. The additional two species which are described, Austrolembidium crassum Hässel and Greeneothallus gemmiparus Hässel, also required the creation of two new genera. The total number of liverwort species now known to be present on South Georgia is sixty-six.     

African Hepatics. XXXVI. Three new species of Colura

Abstract

The following new species are described: Colura usambariea E. W. Jones from Tanzania (Usambara Mountains) and Malawi; Colura saroltae T. Pócs and C. hedbergiana T. Pócs, both from Tanzania (Kilimanjaro).     

The male gametophores of Leucobryum glaucum (Hedw.) Ångstr. and L. juniperoideum (Brid.) C. Muell. in two Welsh woodlands

Abstract

The distribution and variation in size of male gametophores associated with fertile, female cushions of Leucobryum glaucum and L. juniperoideum in two Welsh localities are described. Both dwarf and larger males were present in fruiting cushions of both species; no independent male plants were found. It is suggested that the scarcity of functional males might be a factor limiting sporophyte production in these species.     

Chromosome studies on some Turkish species of Grimmia Hedw.: G. laevigata (Brid.) Brid., G. ovalis (Hedw.) Lindb., G. pulvinata (Hedw.) Sm., G. trichophylla Grev.

In this research, mitotic chromosome numbers in four species of Grimmia Hedw. from Turkey were reported. Mitotic chromosome numbers of three species : Grimmia laevigata (Brid.) Brid. (n = 26), Grimmia ovalis (Hedw.) Lindb. (n = 10), Grimmia pulvinata (Hedw.) Sm. (n = 26) were reported for the first time. Grimmia trichophylla Grev. (n = 13) showed the same chromosome number as in a previous study.     

Molecular phylogenetic investigations of the Viviparidae (Gastropoda: Caenogastropoda) in the lakes of the Rift Valley area of Africa

The freshwater gastropod family Viviparidae is nearly cosmopolitan, but absent from South America. On the African continent, two genera are recognized; the widespread Bellamya and the monotypic Neothauma, which is confined to Lake Tanganyika. Most of the African Bellamya species are confined to the major lakes of the Rift Valley area in Africa, i.e. Lake Albert, Lake Malawi, Lake Mweru, and Lake Victoria. The phylogenetic analyses of mitochondrial (COI and 16S) and nuclear (H3, 18S and 28S) DNA inferred three major lake-clades; i.e. Lake Victoria/Kyoga/Albert, Lake Malawi and Lake Mweru/Bangweulu. The endemic B. rubicunda from Lake Albert and B. unicolor from Lake Kyoga were inferred to be part of the Lake Victoria clade. Bellamya capillata as identified by shell characters was polyphyletic in gene trees. The monophyletic Bellamya species radiation in Lake Malawi was most nearly related to the Lake Victoria/Kyoga/Albert-clade. Taxa from the Zambian lakes, Mweru and Bangweulu, were inferred together and placed ancestral to the other lakes. Neothauma tanganyicense was inferred as the sister-group to the Zambian Bellamya. Within the lake-clades the endemic radiations show very low genetic diversities (0–4.1% in COI), suggesting much faster morphological divergence than molecular divergence. Alternatively, Bellamya in Africa constitutes only a few species with several sub-species or eco-phenotypic morphs. The African viviparids were inferred to be the sister-group to a clade comprising Asian species, and the relatively low genetic diversity between the clades (12.6–15.5% in COI) makes a recent Miocene dispersal event from Asia to Africa much more likely than an ancient Gondwana vicarience distribution.     

The occurrence of tubers in Pohlia pulchella (Hedw.) Lindb. and Pohlia lutescens (Limpr.) Lindb. file

Abstract

Pohlia pulehella and P. luteseens have tubers of characteristic appearance which enable these species to be readily distinguished. Many of the plants collected in Britain before 1966 were wrongly identified. A clearer picture has emerged of the distribution and habitats of the two plants. The occurrence of P. lutescens in Scandinavia, and of male plants in Britain, are reported for the first time.     

A new anhydrobiotic midge from Malawi,Polypedilum pembai sp.n. (Diptera: Chironomidae), closely related to the desiccation tolerant midge,Polypedilum vanderplanki Hinton

The sleeping chironomid (Polypedilum vanderplanki Hinton) lives on temporary rock pools in the semi‐arid tropical regions of Africa. Its larvae are able to survive the dry season in a completely desiccated ametabolic state known as anhydrobiosis. So far, P. vanderplanki was the only species among all insects showing demonstrated anhydrobiotic ability. Here, we show that a new related species originating from Malawi, Polypedilum pembai sp.n. , is also anhydrobiotic and that its desiccation tolerance mechanism is probably similar to what is observed in P. vanderplanki. The new species, P. pembai sp.n. , is described with special attention to the common and different morphological features, compared with P. vanderplanki. Phylogenetic analysis showed that both species are closely related, suggesting that anhydrobiosis evolved only once in their common ancestor about 49 Ma somewhere in Africa, before the divergence of two species, one in the sub‐Saharan area and another in southeastern Africa.     

An explanation of the intermittent occurrence of Physcomitrium sphaericum (Hedw.) Brid.

Abstract

The spasmodic temporal distribution of the rare ephemeral moss Physcomitrium sphaericum is described and an explanation of this unusual periodicity is proposed. Field observations over 44 years have established that the presence of P. sphaericum is closely correlated with periods of summer drought. Evidence from germination experiments and the discovery of a viable buried spore bank suggest that during drying out of mud exposed by drought, spores are unearthed and dormancy is broken by the action of light. It is suggested that these regenerative features, together with a compressed life cycle, enable success in a habitat where conditions for growth occur infrequently and are of a short duration.     

Studies on Timmiella barbuloides (Brid.) Moenk., IV. SEM and TEM characterization of spore wall and first germination stages

Abstract

The spore wall morphology of Timmiella barbuloides (Pottiales, Musci) is described. The spores are catalept, with an ornamentation pattern consisting of unevenly spaced, shortly pedunculated pilum-and gemma-like processes. The spore coat consists of three, unevenly thick layers: intine, exine, and perine. The exine is not involved in wall ornamentation, the processes consisting of perine only. The leptoma, a spore coat area involved in germination, consists of an intine markedly thickening in an area of thinning exine and, outside, with a spore coat area where perinous processes become sparse. On the basis of observations and of the data reported in recent literature the classical definition of the leptoma is modified. It is considered to be a structurally specialized, but not necessarily thin, area.