Anatomy and ultrastructure of haustoria in selected West Australian parasitic angiosperms

Author(s):  
John Kuo ◽  
John S. Pate

Our understanding of nutrient transfer between host and flowering parasitic plants is usually based mainly on physiological concepts, with little information on haustorial structure related to function. The aim of this paper is to study the haustorial interface and possible pathways of water and solute transfer between a number of host and parasites.Haustorial tissues were fixed in glutaraldehyde and embedded in glycol methacrylate (LM), or fixed in glutaraldehyde then OsO4 and embedded in Spurr’s resin (TEM).Our study shows that lumen to lumen continuity occurs between tracheary elements of a host and four S.W. Australian species of aerial mistletoes (Fig. 1), and some root hemiparasites (Exocarpos spp. and Anthobolus foveolatus) (Fig. 2). On the other hand, haustorial interfaces of the root hemiparasites Olax phyllanthi and Santalum (2 species) are comprised mainly of parenchyma, as opposed to terminating tracheads or vessels, implying that direct solution transfer between partners via vessels or tracheary elements may be limited (Fig. 3).

1986 ◽  
Vol 34 (5) ◽  
pp. 505 ◽  
Author(s):  
EM Watson

A cytological survey, using root tip mitotic cells and supplemented by some crosses and pollen fertility studies, was carried out on plants of 55 populations of the Australian annual Bulbine sernibarbata s.1. (Liliaceae). There are 4x, 8x and 12.x populations.The 4x forms are almost completely confined to eastern Australia and comprise populations of two kinds: (1) 28-chromosome types, corresponding in morphology to B. alata Baijnath, which to date has had limited taxonomic acceptance; (2) 26-chromosome types with the morphology of B. sernibarbata s. str. The alata form occurs in arid, the sernibarbata in more mesic, areas. The eastern 8x populations are mainly 2n = 54 and are intermediate between the other two taxa in both range and morphology. This suggests an allopolyploid origin based on hybridisation between the alata and sernibarbata types. The western 8x populations are nearly all 2n = 52, with much interpopulation variation in karyotype and a mesic distribution similar to that of the eastern 26-chromosome types. The karyotypic diversity parallels the species richness of other genera in southwestern Australia and indicates that the complex may be older than the corresponding polyploid complex within the perennial B. bulbosa s.1. The 12x (2n =78) populations are confined to arid and transitional rainfall areas of Western Australia. The identification of a distinctive 28-chromosome karyotype for the alata group gives support to the recognition of B. alata Baijnath, and, by providing a logical euploid bridge between the chromosome numbers of the African (2n = 14) and Australian species, strengthens the arguments for treating the two groups as congeneric.


Zootaxa ◽  
2006 ◽  
Vol 1369 (1) ◽  
pp. 43 ◽  
Author(s):  
SULA SALANI ◽  
TITO M.D.C. LOTUFO ◽  
EDUARDO HAJDU

Sigmaxinella cearense sp. nov. is described here on the basis of a single specimen collected in 2004 at Parque Estadual Marinho da Pedra da Risca do Meio, off Fortaleza, Ceará, Brazil. This is the first record of Sigmaxinella for the Atlantic Ocean. The new species differs from the other eleven Sigmaxinella species by the absence of raphides/microxea, and is the only species with a single category of styles as megascleres (mean length 435µm, mean width 12µm), and sigmas (mean length 21µm). The new species appears to be closer to Australian species of Sigmaxinella, on the basis of overall spicule morphology (mainly dimensions and categories of megascleres). This could be suggestive of a transpacific track for the colonization of the South Atlantic, instead of the shorter Agulhas track.Key words: Sigmaxinella, taxonomy, Parque Estadual da Pedra da Risca do Meio, sponge, new species, sandstone reef, Brazil


Phytotaxa ◽  
2016 ◽  
Vol 245 (4) ◽  
pp. 251 ◽  
Author(s):  
Bernadette Grosse-Veldmann ◽  
Barry J Conn ◽  
Maximilian Weigend

Taxon differentiation in Urtica from Australia and New Zealand initially appears to be uncomplicated, with taxa being easy to distinguish. However, a revision of the type material, more recent collections and a comparison of Australian and New Zealand material shows that three of the names are misapplied. Urtica gracilis (as U. dioica subsp. gracilis, North America) has been reported as introduced to New Zealand, but molecular data retrieve the corresponding specimens with the other NZ-species and we argue that they belong to the polygamous Australian species Urtica incisa. A critical revision of the protologues and type collections reveals that the names Urtica incisa, originally described from mainland Australia, and U. incisa var. linearifolia from Tasmania, have been misapplied to New Zealand taxa. Both New Zealand “Urtica linearifolia” and “U. incisa” represent unnamed taxa and are here formally described as Urtica perconfusa and Urtica sykesii, respectively. Urtica perconfusa corresponds to what is erroneously known as U. linearifolia. Urtica sykesii is an overlooked species, erroneously interpreted as U. incisa in New Zealand. It may be differentiated from U. incisa Poir. by its smaller, deltoid leaf lamina with a truncate to subcordate base (versus truncate to cuneate), fewer leaf teeth (9–12 on each side rather than 14–20 in U. incisa) and smaller plant size (20–60 cm rather than 60–200 cm in U. incisa). We found evidence for the presence of true introduced U. dioica subsp. dioica in New Zealand, but not for U. gracilis. Rather, New Zealand specimens assigned to the putatively introduced northern hemisphere U. gracilis belong to U. incisa as described from Australia. Typifications for the species treated here are provided, including an updated key to the Australian and New Zealand taxa. There are thus six native species of Urtica in New Zealand, four of them endemic, and two also indigenous in Australia.


2016 ◽  
Vol 29 (5) ◽  
pp. 358 ◽  
Author(s):  
Matt A. M. Renner ◽  
Margaret M. Heslewood ◽  
Simon D. F. Patzak ◽  
Alfons Schäfer-Verwimp ◽  
Jochen Heinrichs

Molecular and morphological data support the recognition of seven species of Chiastocaulon in Australia, of which four, namely C. braunianum and C. geminifolium comb. nov. from tropical north-eastern Queensland and C. proliferum and C. flamabilis sp. nov. from Tasmania (and New Zealand), represent new records. The other three species accepted for Australia are C. biserialis, C. dendroides and C. oppositum. Chiastocaulon conjugatum is excluded from the Australian flora, because previous Australian records are based on misidentifications of C. braunianum and Plagiochila retrospectans. Pedinophyllum monoicum, reported for Australia from a single locality in Victoria, is excluded from the Australian flora because all credible records are based on misidentifications of Syzygiella tasmanica. The Papua New Guinean Chiastocaulon takakii comb. nov. is reinstated from synonymy under C. dendroides on the basis of morphological evidence. Descriptions and illustrations of all Australian species, and dichotomous keys to species of the Chiastocaulon lineage in Australia and New Zealand, are provided.


1968 ◽  
Vol 16 (2) ◽  
pp. 197 ◽  
Author(s):  
RN Baldock ◽  
HBS Womersley

Two species of southern Australian marine algae have been previously placed in Bornetia. One, B. binderiana (Sonder) Zanardini, shows the generic features of the type species from Europe (B. secundiflora), and an additional species, B. tenuis, is also described for the genus. Study of the type and the above two Australian species shows that Bornetia is characterized by subdichotomous filaments of elongate cells, a 5-6(-8)-celled fertile axis developing procarps successively and also non-functional pseudocarpogonia, an involucre produced from the lower cells of the fertile axis, and a large stellate fusion cell; and by the production of tetrasporangia and spermatangial heads in condensed clusters in which the terminal branch cells curve around the cluster as an involucre. The other Australian species, B. ? Meredithiana J. Agardh, has procarps confined to the subterminal cell of a 3-celled fertile axis, and after fertilization sterile cells associated with the procarp produce an inner involucre around the carposporophyte, which has a massive fusion cell. Sessile polysporangia are borne in condensed lateral branch clusters. A new genus, Involucrana, is proposed for this species. Its relationships are probably with Sphondylothamnion, which also differs from other known Ceramiaceae in having a similar inner involucre.


2013 ◽  
Vol 16 (4) ◽  
pp. 464-472 ◽  
Author(s):  
Jason D Smith ◽  
Mark C Mescher ◽  
Consuelo M De Moraes

PhytoKeys ◽  
2019 ◽  
Vol 119 ◽  
pp. 53-66 ◽  
Author(s):  
Marc Pignal ◽  
Luciano Paganucci de Queiroz

Indigoferamonierana M.Pignal & L.P.Queiroz, sp. nov. and Indigoferadumbeana M.Pignal & L.P.Queiroz, sp. nov., two new species from New Caledonia, are described and illustrated. Both new species have been collected for a long time, but most herbarium specimens were named as the Australian species Indigoferaaustralis, even though they clearly stand apart from this species and the other New Caledonian species of the genus. Indigoferamonierana can be diagnosed by the tall virgate shrubby habit, leaves with an articulate rachis and 7–11 widely obovate to orbiculate leaflets with greyish undersurface and almost invisible venation. Indigoferadumbeana can be recognized by the arborescent habit, leaves with 15–19 elliptical leaflets, small, c. 6 mm long flowers, and ellipsoid seeds. Preliminary IUCN assessments are provided for both species. A key is provided for all species of Indigofera recorded from New Caledonia.


2014 ◽  
Author(s):  
Tim Dolby ◽  
Rohan Clarke

Finding Australian Birds is a guide to the special birds found across Australia's vastly varied landscapes. From the eastern rainforests to central deserts, Australia is home to some 900 species of birds. This book covers over 400 Australian bird watching sites conveniently grouped into the best birding areas, from one end of the country to the other. This includes areas such as Kakadu in the Top End and rocky gorges in the central deserts of the Northern Territory, the Great Barrier Reef in Queensland, rainforests distributed along the eastern Australian seaboard, some of the world's tallest forests in Tasmania, the Flinders Ranges and deserts along the iconic Strzelecki and Birdsville Tracks in South Australia, and the mallee temperate woodlands and spectacular coastlines in both Victoria and south west Western Australia. Each chapter begins with a brief description of the location, followed by a section on where to find the birds, which describes specific birdwatching sites within the location's boundaries, and information on accommodation and facilities. The book also provides a comprehensive 'Bird Finding Guide', listing all of Australia's birds with details on their abundance and where exactly to see them. Of value to both Australian birdwatchers and international visitors, this book will assist novices, birders of intermediate skill and keen 'twitchers' to find any Australian species.


1985 ◽  
Vol 33 (4) ◽  
pp. 547 ◽  
Author(s):  
BK Cantrell

The Australian species of Exorista Meigen are revised and the genus redescribed from these species. E. auriceps Macquart is confirmed as a synonym of E.flaviceps Macquart, and E. mungomeryi (Baranov) is synonymized with E. curriei (Curran). E. quadriseta (Baranov) is recorded from Australia for the first time. A new species is described below as E. norrisi, but five other species are left unnamed until further material is available. A key to the 14 species known in Australia is provided. Knowledge of the remaining seven genera of Exoristini in Australia is insufficient for their detailed treatment but pertinent comments on each are given. The presence of Phorinia Robineau-Desvoidy in Australia is confirmed. A partial list of the distinguishing features of the Exoristini is included.


Zootaxa ◽  
2007 ◽  
Vol 1657 (1) ◽  
pp. 57-67 ◽  
Author(s):  
WILLIAM B. RUDMAN

Two new species of the nudibranch genus Okenia Menke, 1830 (Goniodorididae) are described, one from eastern Australian waters and one from the western Indian Ocean. Okenia atkinsonorum sp. nov. is the third Australian species reported to feed on the bryozoan Pleurotoichus clathratus (Harmer, 1902) and is very similar in external shape and colour to the other two species, O. hallucigenia Rudman, 2004 and O. stellata Rudman, 2004. Okenia rhinorma sp. nov. is reported from Tanzania and the Red Sea. Its body shape and anatomy suggest it is related to the ascidian-feeding group in the genus characterised by O. aspersa (Alder & Hancock, 1845).


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