Plate 495. Lechenaultia linarioides Goodeniaceae

Summary.  Lechenaultia linarioides DC. ( Goodeniaceae ) is a tangled shrub with rather more woody stems than the other species. It has been grown in Europe since the 1840s.     

Plate 493. Lechenaultia biloba Goodeniaceae

Summary.  Lechenaultia biloba Lindl. ( Goodeniaceae ), blue leschenaultia , one of Western Australia's well-known blue flowers, has been grown in Britain since the 1840s.     

Patterns of diversification in New Zealand Stylidiaceae

Phylogenetic analysis of ITS and rbcL sequences show that New Zealand Stylidiaceae fall into two distinct lineages differing in species richness. Each lineage represents a unique dispersal event to New Zealand occurring at different times during the evolutionary history of the family. One lineage comprises seven species of Forstera and Phyllachne, while the other consists solely of Oreostylidium subulatum. The origin of the Forstera/Phyllachne lineage in New Zealand is equivocal; either a South American or a Tasmanian origin is equally parsimonious. Possible sister groups are F. bellidifolia in Tasmania and P. uliginosa in South America. Oreostylidium subulatum has an Australian origin. In our analyses O. subulatum is nested in a clade composed entirely of species of Stylidium, almost all of which are endemic to Australia. Species of Phyllachne share a cushion habit with the outgroup Donatia (Donatiaceae) that may have preadapted them to alpine environments in New Zealand. The New Zealand Stylidiaceae have small, white, actinomorphic flowers that are well adapted to the unspecialized pollinator fauna. Forstera and Phyllachne share this trait with Donatia; however, the small, white flowers of Oreostylidium are a dramatic departure from the colorful, highly specialized flowers of Stylidium.     

The effect of systemic rusts and smuts on clonal plants in natural systems

This paper focuses on the effects of systemic rust and smut fungi on non-crop clonal plants and on the role of clonal growth in disease escape. Systemic rusts and smuts have a major effect on individual plants and populations as they affect growth and survival. Diseased plants may become distorted, stunted and/or elongated. However, the results are very variable. For example, growth and competitive ability may be reduced or increased, and survival may or may not be affected. Furthermore, clonal plants are able to escape systemic diseases by vigorous growth or by the production of long rhizomes. It is argued that a better understanding of the effects of systemic rusts and smuts on clonal individuals and populations requires not only more studies but ones that particularly focus on the life history of both host plant and pathogen and the mechanisms that allow parts of the clonal system to escape disease.     

Plate 496. Lechenaultia striata Goodeniaceae

Summary.  Lechenaultia striata F. Muell. ( Goodeniaceae ) is a desert species of upright habit, with pale blue to creamy white flowers. It is unknown in cultivation outside Australia.     

Tuberculina: rust relatives attack rusts

Molecular sequence data together with ultrastructural features were used to infer the phylogenetic position of Tuberculina species. Additional ultrastructural characteristics were used to determine their mode of nutrition. We investigated ultrastructural morphology of the type species Tuberculina persicina and determined base sequences from the D1/ D2 region of the nuclear large-subunit ribosomal DNA of the three commonly distinguished Tuberculina species, T. maxima, T. persicina and T. sbrozzii. Analyses of sequence data by means of a Bayesian method of phylogenetic inference using a Markov Chain Monte Carlo technique reveal the basidiomycetous nature of Tuberculina. Within the Urediniomycetes, Tuberculina clusters as a sister group of Helicobasidium, closely related to the rusts (Uredinales). This phylogenetic position is supported by the uredinalean architecture of septal pores in Tuberculina. In addition, we present aspects of the ultrastructural morphology of the cellular interaction of Tuberculina and rusts showing a unique interaction with large fusion pores, revealing the mycoparasitic nature of Tuberculina on its close relatives, the rusts.     

Hunting rare rusts in NW Wales

An earlier version of this article appeared in the Herefordshire Fungus Survey Group's News Sheet 15 (2008). We are grateful to the editor for permission to use it here.     

Plate 497. Lechenaultia tubiflora Goodeniaceae

Summary.  Lechenaultia tubiflora R.Br. ( Goodeniaceae ) heath leschenaultia has narrow, tubular flowers that show great variation in colour. It has proved difficult in cultivation.     

Plate 492. Lechenaultia acutiloba Goodeniaceae

Summary.  Lechenaultia acutiloba Benth. ( Goodeniaceae ) is a rare, greenish-yellow-flowered species of compact form, unknown in cultivation in Britain.     

Lack of communication rusts and ages stem cells

Comment on: Ishikawa ET, et al. Proc Natl Acad Sci USA 2012; 109:9071-6.     

Plate 494. Lechenaultia hirsuta Goodeniaceae

Summary.  Lechenaultia hirsuta F. Muell. ( Goodeniaceae ) is the only hairy species of the genus. It is an openly branched plant with large, scarlet flowers.     

Karyotype analysis in Stylidium crossocephalum (Angiospermae:Stylidiaceae)

Qualitative studies of karyotypes were carried out on 79 plants of Stylidium crossocephalum from 28 collection sites. The sample included 7 distinct karyotypic classes which could be resolved into 5 clearly distinguishable haploid karyotypes or genomes. Three genomes, J, K and L, were localised in an area covering a southern portion of the species range while the other two genomes, A and B, were found in a region 90km to the north. Two different genome heterozygotes were found, one characterised by a J/K karyotype, the other by an A/B karyotype. —Karyotypic studies of a synthetic hybrid and its two parents showed that the chromosomes of the constituent genomes of the hybrid could be readily and confidently discerned in the karyotypes of the parents. These studies demonstrated that the identification of genomes by the qualitative attributes of their constituent chromosomes constitutes a reliable analytical technique. — Statistical analyses using arm ratio and percentage length measurements of chromosomes from plants allocated to the two groups of genomes confirmed the differences between marker chromosomes and demonstrated additional statistically significant differences among the non marker chromosomes. Some of these statistical differences may be attributable to technical problems inherent in the karyotyping procedures. In two instances, however, they could be convincingly argued as real, demonstrating a further component of chromosome variation in S. crossocephalum.     

B chromosomes in Stylidium crossocephalum (Angiospermae:Stylidiaceae)

Populations of Stylidium crossocephalum contain two common types of B chromosomes, macro B chromosomes and micro B chromosomes. The macro B chromosomes are telocentric, slightly smaller than the smallest A chromosomes and mitotically unstable. They have so far been found associated with 6 of the 16 stable genomes known in S. crossocephalum, occurring in populations covering a substantial portion of the species range. Micro B chromosomes are about one third the length of the smallest A chromosome, acrocentric and show some mitotic instability. They occur associated with 3 stable genomes in populations found in the more medial regions of the species range. Both types of B chromosomes generally show regular behaviour during meiosis, although when two or more are present their pairing efficiency is reduced when compared to the A chromosomes. In addition a single very large mega chromosome was found in a single cell of one heterokaryotypic plant. Its origin although conjectural at this stage may be of relevance in understanding the origin of macro and micro B chromosomes in this species.     

The behaviour and possible cytoevolutionary significance of B chromosomes in Dampiera linearis (Angiospermae: Goodeniaceae)

Nineteen percent of diploid plants at the ecotonal junction between laterite inhabiting diploid and coastal sandplain inhabiting tetraploid forms of Dampiera linearis carry from 1 to 6 B chromosomes. The B chromosomes usually form temporary pseudovalent associations at diplotene and often A chromosome/B chromosome connections can be seen. Some plants with high numbers of B chromosomes exhibit A bivalent nondisjunction. Although undivided B chromosomes are distributed to TI poles at random, the nondisjoined bivalents show a polarised movement to poles with high numbers of Bs. It is suggested that the pre-metaphase-1 A/B associations provide a basis for non-random assortment in genomically hybrid individuals and that nonreduction, associated with wholesale nondisjunction induced by very high numbers of B chromosomes, resulted in the generation of polyploids which were reproductively isolated from their diploid progenitors, heterotic and adapted to the coastal plain environment.     

Evidence of protocarnivory in triggerplants (Stylidium spp.; Stylidiaceae)

Australian triggerplants (Stylidium spp.; Stylidiaceae) trap small insects using mucilage-secreting glandular hairs held at various points on their inflorescence stems and flower parts. Triggerplants are generally found in habitats also containing genera of plants already accepted as carnivorous, two of which (Drosera, Byblis) use the same basic mechanism as Stylidium to trap their prey. In the herbarium, sheets of triggerplants and of accepted groups of carnivorous plants held similar numbers of trapped insects, and in the field, trapping of small prey per unit of glandular surface area was the same at a given site for triggerplants and for nearby carnivorous plants at three sites in northern Australia. Even more important, protease activity was produced by glandular regions of both triggerplants and Drosera after induction with yeast extract. A panel of negative and positive controls, including use 1) of plants grown in tissue culture, which therefore lack surface microorganisms, and 2) of protease inhibitors, shows that this activity 1) is generated by the glandular regions of the triggerplant itself, not by organisms that might reside on the surface of the plants, and 2) is due to proteases. All of this evidence taken together provides strong evidence of protocarnivory in Stylidium, something not previously suggested in the scientific literature, though the insect trapping has been noted informally. Experiments remain to be done to determine nutrient uptake, so triggerplants may well be fully carnivorous.