bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of a Hybrid Swarm Between Eucalyptus risdonii Hook. F. And E. amygdalina Labill
Authors: Potts BM , Reid JB
Published: December 2005

E. risdonii is a rare Tasmanian endemic which occurs as a series of small disjunct populations within a more-or-less continuous population of a closely related species, E. amygdalina. In localized areas (e.g.
Risdon, Tasmania), patches of high phenotypic diversity are encountered, with individuals
encompassing the complete phenotypic range between these two species. Progeny trials indicate a large
heritable component to this variation. Open-pollinated progenies from intermediate mothers exhibit
greater variability than those from either pure species, which strongly suggests that these intermediate
phenotypes are a result of hybridization. Progenies from pure species mothers near a hybrid swarm are
more variable than those from pure stands. There is a greater proportion of seedlings which match the
artificially produced F1 in open-pollinated progenies from E. amygdalina than from E. risdonii mothers.
In addition, progenies from intermediate mothers show a bias toward E. risdonii types, which implies
that they are predominantly outcrossing to E. risdonii. This evidence suggests an asymmetrical flow of
genes by pollen migration from E. risdonii into the hybrid swarm and surrounding E. amygdalina.
Little difference in seedling vigour or mortality occurred between seedlings from the various parental
phenotypes, although differences in seed output per capsule and germination were apparent. The specific
identity of E. risdonii and E. amygdalina is usually maintained in parapatry by a range of mechanisms
including their specific ecological preference, reduced hybrid fitness and differences in flowering
phenology. The reasons for the major zones of hybridization occurring at boundaries on ridge tops as
opposed to those on the dry slopes are discussed.
The Genesis of Form in Casuarinaceae
Authors: Williams RF , Metcalf RA
Published: December 2005

The growth and development of the shoot apex of Casuarina distyla, in which the leaves commonly occur in whorls of 6-8 members, is described. The mature apex of C. torulosa, a species with only four leaves per whorl, is also described. Stages in the development of the apex of C. distyla are
illustrated with three-dimensional scale drawings.
The fused stem-and-leaf nature of the vegetative axis is recognized and the growth of the blade, tube
and buttress portions of the axes is presented in units of length and volume. Stages in the development
of axillary buds are illustrated with three-dimensional scale drawings.
Phyllotactic parameters for whorled systems of phyllotaxis in Nerium and Casuarina are presented
along with those for decussate systems in Eucalyptus.
The role of physical constraint in the genesis of form and the determination of rates of growth in
shoot apices are discussed and it is suggested that rapid maturation of tissues may contribute to the
continuous fall in the relative growth rate of the leaves.
Spikelet Structure in Panicum australiense. (Poaceae): Taxonomic and Ecological Implications
Authors: Berg RY
Published: December 2005

The rhachillar stipe in Panicum australiense is prolonged and expanded below the terminal floret to form
a zygomorphic body. The diaspore ultimately detaches below this body, the mature fruit falling with
the body as a swollen appendage on its base. This appendage, apparently, acts as an elaiosome and the
means for myrmecochorous dispersal of the caryopsis. The upper rim of the appendage is irregular,
extending into two acute lobes on the ventral side of the fruit. These lobes are not homologous with
the two basal fruit appendages characterizing Ichnanthus. Australian Panicum species with a rhachillar
appendage like that of P. australiense probably should constitute a genus of their own.
Biological Nitrogen Fixation and Root-Nodule Bacteria (Rhizobium Sp. and Bradyrhizobium Sp.) In Two Rehabilitating Sand Dune Areas Planted With Acacia Spp
Authors: Barnet YM , Catt PC , Hearne DH
Published: December 2005

This paper reports a study of biological nitrogen fixation in two sand dune regions of New South Wales where planted Acacia spp. had been used in revegetation programmes. At one location (Bridge Hill Ridge), natural regrowth had produced a complex plant community, and native legumes in addition to the planted acacias were present. The other area (Wanda Beach) was a grossly disturbed site which contained only the planted species. Symbiotic fixation in association with Australian legumes occurred at both locations at rates within the range reported by other authors. Distinct seasonal changes were apparent, with higher activities in the cooler months. The legume association seemed the only source of biologically fixed nitrogen at Bridge Hill Ridge, but at Wanda Beach cyanobacteria in an algal mat also made a contribution. Fast and slow-growing bacterial strains were obtained from root nodules of native legumes at both sites and were classed as Rhizobium sp. and Bradyrhizobium sp., respectively. This division was supported by the pattern of serological affinities of the isolates and by differences in their protein profiles demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Two atypical types of root-nodule bacteria were found at Bridge Hill Ridge: non-nodulating, fast-growing isolates and an abnormally slow-growing Bradyrhizobium sp.
Removal of Seed of Grevillea pteridifolia (Proteaceae) by Ants
Authors: Majer JD , Lamont BB
Published: December 2005

Seed-taking by ants has rarely been recorded in Australian Proteaceae. Recent work in northern
Australia showed that seed of Grevillea pteridifolia is taken by ants as readily as those of certain
elaiosome-bearing Acacia spp. The hard, flat seed is completely surrounded by a brittle, papery wing
which is consumed by ants. The wing contributes 3-5% of seed mass and has a higher concentration
of protein, available carbohydrate, fat and certain micronutrients than the seed body (embryo + coat).
Although present throughout the seed, cyanide is concentrated in the seed coat. The high lipid and
protein content of the wing explains its success as an ant attractant while the hard, cyanide-containing
seed coat may deter seed predation. The apparent absence of seed taking by ants in closely related
proteaceous genera in Australia may be attributed to serotiny as the general condition, while Grevillea
spp. release seed annually and should benefit from the storing of seed in soil by ants.
A New Species of Descolea (Agaricales) From Western Australia, and Aspects of Its Ectomycorrhizal Status
Authors: Bougher NL , Malajczuk N
Published: December 2005

Descolea maculata sp. nov. is described, illustrated and compared with other species of the genus. A
Gondwanaland/Nothofagus origin proposed for the genus is discussed in the light of the Western
Australian record. Ectomycorrhizae initiated by D. maculata on roots of Eucalyptus diversicolor and
E. marginata, under both aseptic and non-sterile conditions, provide confirmation of the
ectomycorrhizal status of the genus Descolea. Cystidia associated with the fungal mantle are similar to
those reported for other mycorrhizal fungi of eucalypts.
Moving analysis of interspecific associations
Authors: Lange RT , Sparrow AD
Published: December 2005

A method of vegetation analysis is described in which interspecific associations are observed from a sampling block in each of its overlapping sequential positions as it moves across landscape. Its advantages are, firstly, that a graph of block associations (ordinate) against sequential block positions (abscissa) reveals intersected homogeneous communities as horizontal low sections separated by sharp peaks. Secondly, change in the value and sign of any pairwise interspecific association can be followed by similar plotting. Both of these features are illustrated.
Variation in the Eucalyptus gunnii-archeri Complex. III. Reciprocal Transplant Trials
Authors: Potts BM
Published: December 2005

Two multicharacter clines in the more or less continuous stands of Eucalyptus gunnii-archeri on the
Central Plateau, Tasmania, are genetically based and appear to parallel independent habitat gradients.
Results from experimental gardens established near the extremes of each cline suggest that these clines
are at least partly maintained by spatially varying selective forces. Spatial variation in population fitness
could be partly attributed to a differential response to drought, frost and insect predation.
Most characters associated with extension growth (e.g. height, internode length, leaf size) exhibited
marked phenotypic plasticity. In contrast, several characters of taxonomic importance in the complex,
and which vary markedly between populations (e.g. seedling leaf shape, glaucousness), exhibited little
environmental modification. The ontogenetic pattern varied between populations and, for many charac-
ters, the direction of environmental modification was the same as the direction of genetic differentiation.
Flowering Biology and Phenology of Banksia integrifolia and B. spinulosa (Proteaceae) in New England National Park, N.S.W
Authors: McFarland DC
Published: December 2005

The flowering biology and phenology of two species of Banksia, including anthesis rates, inflorescence survivorship and nectar production, were examined in the Northern Tablelands, N.S.W. Rainfall, temperature and wind are all important factors in determining nectar productivity and availability. The species investigated here are compared with other banksias studied elsewhere in Australia.
Regeneration of Three Tree Species in Arid South-Eastern Australia
Authors: Chesterfield CJ , Parsons RF
Published: December 2005

Grazing effects by introduced mammals on tree seedlings in the arid zone have caused concern for the
long-term future of some tree species. This was investigated by measuring stem girths of Casuarina
cristata Miq., Heterodendrum oleifoliurn Desf. and Myoporum platycarpum R.Br. in arid-zone wood-
lands. Episodic seedling regeneration of Myoporum is inferred following series of wet years in the 1950s
and 1970s. Although young Myoporum plants appear unpalatable to stock, regeneration may be sup-
pressed by rabbit-grazing in some areas. Almost no Heterodendrurn seedlings were found but suckering
was common after burning and clearing. This species is highly palatable to grazing mammals and
suckers may grow to safety above the browse line only where stock are absent. Evidence for recent
Casuarina seedling regeneration was limited to one cohort, on a site that had been flooded. While
suckers can be found locally where surface roots become exposed, suckering appears insufficient to
perpetuate many Casuarina stands.
Mammal-grazing seems important in strongly limiting regeneration. While Casuarina and
Heterodendrum stand densities decline due to natural senescence and occasional fire, the only species
regenerating into gaps is Myoporum. There is concern for the future of Casuarina and Heterodendrum,
given their widespread failure to regenerate despite the wettest 3 years ever recorded, in 1973-75. On
pastoral land, at least 10 years without stock-grazing might be needed for successful regeneration of
Heterodendrurn. In reserves, some nature conservation programs for woodlands might require virtual
eradication of all exotic mammalian herbivores, including goats.
The Ecology of the Mallee Outlier of Eucalyptus behriana F. Muell. Near Melton, Victoria
Authors: Myers BA , Ashton DH , Osborne JA
Published: December 2005

An outlier of mallee vegetation occurs south of the Great Dividing Range in Victoria in a rain shadow region (annual rainfall approx. 500 mm) about 50 km west of Melbourne. A Eucalyptus behriana open-scrub with a sparse understorey of chenopods, mosses, lichens and some grasses occurs on solonetz soil on lateritized Tertiary sandy clays and on skeletal soils on Ordovician slates and sandstones. The dryness of the mallee site is probably exacerbated by the smaller rate of water infiltration and greater salinity of the solonetz soil under E. behriana compared with the solodic soil, in the moister area further north, under an open-forest of E. microcarpa. The multistemmed habit of E. behriana appears to be partly genetically fixed. Hollow lignotuberous rings, filled to a depth of about 15-25 cm with brown, nutrient-rich humus, are common. Pattern analysis of the distribution of stems of E. behriana indicated strong clumping at about 9 m², due to the multistemmed habit, and weaker clumping at about 600 m², which correlated with the size of groups of dense, spindly individuals of E. behriana, resulting from a past phase of gap regeneration.
Zinc Nutrition of Jarrah (Eucalyptus marginata Donn ex Smith) Seedlings
Authors: Wallace IM , Dell B , Loneragan JF
Published: December 2005

The relationships of seven levels of zinc supply to dry matter and zinc concentration were assessed for jarrah (Eucalyptus marginata Donn ex Smith) seedlings grown for 84 days in a zinc-deficient sand in the glasshouse. Zinc deficiency symptoms appeared within 28 days of sowing as a change in leaf colour of young leaves from green to bronze. Later, red areas developed and these became necrotic in severe cases. These symptoms were accompanied by decreased shoot and root dry weights. Zinc concentrations in various plant parts were low and, with the exception of the shoot apex, showed little response to zinc supply. Concentrations at the shoot apex varied from 3�g/g in deficient plants to 12�g/g in plants with adequate zinc supply. We suggest that of the plant parts analysed, the shoot apex is the only one which may be useful in defining zinc status of jarrah seedlings. Critical zinc concentration for this tissue was between 10 and 12 �g/g dry matter. Phosphorus concentrations in all plant parts, except the shoot apex, increased to very high levels with increasing zinc deficiency. It is suggested that some zinc deficiency symptoms of jarrah seedlings, e.g. necrosis, may have resulted from phosphorus accumulation due to zinc deficiency.
Establishment, Suppression and Growth of Eucalyptus delegatensis R.T. Baker In Multiaged Forests .II. Sapling Growth and Its Environmental Correlates
Authors: Bowman DMJS , Kirkpatrick JB
Published: December 2005

Seedling and sapling regrowth occupies gaps and includes part of the understorey in the multiaged
Eucalyptus delegatensis dry forests of central Tasmania. This regrowth is even-aged for any particular
area. Variation in sapling height is symmetrical across east to west sections of gaps, 20-50 m diam.,
but asymmetrical in the north to south sections, where the tallest seedlings are found to the south.
Density, height, diameter and wet weight of E. delegatensis regrowth are highly positively correlated
with the distance to the nearest tree but are only related to solar radiation in the gaps. Concentrations
of most major plant nutrients in the surface soil, and soil moisture-holding capacity, have no strong
relationship with the various growth measures. Thus, adult trees suppress sapling growth independent
of incident solar radiation, while sapling growth outside the influence of adult trees increases with
increasing incident solar radiation.
Establishment, Suppression and Growth of Eucalyptus delegatensis R.T. Baker In Multiaged Forests .III. Intraspecific Allelopathy, Competition Between Adult and Juvenile for Moisture and Nutrients, and Frost Damage to Seedlings
Authors: Bowman DMJS , Kirkpatrick JB
Published: December 2005

Field and pot experiments were designed to test the relative roles of allelopathy, competition for
moisture and competition for nutrients in the suppression and growth of Eucalyptus delegatensis. In pot
experiments litter cover was associated with slightly slower growth rates than in other treatments. A
fertilization treatment was associated with increased growth rates in both trenched and untrenched
situations in a field experiment, but the effect of fertilization was subdued in comparison with the effects
of trenching or of total tree removal in the clear-felling treatment. Saplings and seedlings in the forest
were under significantly greater moisture stress, as indicated by xylem pressure potential and stomata1
resistance, than those growing in the adjacent clear-felled areas. Surface soils in clear-felled areas had
moisture contents above the level which caused seedling stress while surface soils within the forest were
often below this level. These findings suggest that adult trees suppress seedling and sapling regrowth
largely through their effect on soil moisture. However, another form of seedling growth suppression also
occurs in the open as a result of frost damage.
Synthesis in Growth Pouches of Mycorrhizae Between Eucalyptus pilularis and Several Strains of Pisolithus tinctorius
Authors: Grenville DJ , Peterson Rl , Ashford AE
Published: December 2005

Eucalypt mycorrhizae were synthesized in non-sterile plastic growth pouches. Mycorrhizae occurred on second-order roots 6-9 days after inoculation of seedlings. External morphology and internal anatomy of mycorrhizae are similar to those produced in soil. The growth pouch is particularly useful for observing the development of mycorrhizae and sampling tissues of known ectomycorrhizae without disturbing the root system. For these reasons, as well as the rapidity of ectomycorrhizal synthesis, this method represents an important advance in technology. Five strains of Pisolithus tinctorius were tested in growth pouches and found to form ectomycorrhizae with Eucalyptus pilularis.
The Genus Clavulina (Basidiomycetes) in Southeastern Australia
Authors: Corner EJH
Published: December 2005

Mistakes are pointed out in the identification of four of the seven species of Clavulina recorded for south-eastern Australia by R. H. Petersen. Attention is drawn to other errors.
The Genus Pyxine (Physciaceae, Lichenized Ascomycetes) in Australia
Authors: Rogers RW
Published: December 2005

Following morphological, anatomical and chemical studies, 15 species of Pyxine (Physciaceae, lichenized ascomycetes) are recorded for Australia. Their classification, distribution and habitats are discussed. The following taxa are reduced to synonymy: Pyxine cocoes var. endoxantha Müll. Arg. and P. meissneri var. rinodinoides Vainio with P. berteriana (Fée) Imshaug; P. brachyloba Müll. Arg., P. nitidula Mull. Arg. and P. microspora Vainio with P. minuta Vainio; P. meissneri var. convexula Malme, P. albida Magnusson and P. pringlei Imshaug with P. petricola; P. meissneri var. subobscurascens Malme with P. pungens Zahlbr.; P. retirugella var. laevior Vainio, P. retirugella var. capitata Zahlbr., P. copelandii Vainio, P. asiatica Vainio, and P. patellaris Kurok, with P. retirugella Nyl.; and P. prominula Stirton with P. cocoes (Sw.) Nyl. The new species P. isidiolenta R. W. Rogers is described and the new name P. linearis R. W. Rogers is proposed for P. retirugella var. endoxantha forma sorediosa Mull. Arg.
Mineral Nutrient Composition of Leaves and Fruits of Selected Species of Grevillea From Southwestern Australia, With Special Reference to Grevillea leucopteris Meissn
Authors: Hocking PJ
Published: December 2005

A study was made of mineral nutrient concentrations and distributions in leaves and fruits of 10 species of Grevillea from diverse localities in south-western Australia. Seeds of all species contained high concentrations of mineral nutrients, despite the nutrient-poor soils of their habitats. Leaves and the leathery follicles which contained the seeds typically had very low levels of nutrients. With few exceptions, the concentration and distribution patterns of a particular nutrient in fruits were similar in all the species studied. In these species, over 90% of the P content, and between 50 and 70% of the N, Zn and Cu contents of a fruit were located in seeds. Some species accumulated very high concentrations of a particular nutrient, e.g. Ca in seeds and leaves of G. leucopteris, K in seeds of G. tripartita and Fe in follicles of G. petrophiloides. Ratios of K : Ca concentrations were low (< 1) in seeds of G. candelabroides, G. petrophiloides, G. pinaster and especially G. polybotrya and G. leucopteris, which are characterized by high Ca concentrations in their seeds. In the Grevillea species studied, Na C1 and Fe accumulated in the leathery follicle but not in the seeds. A study of G. leucopteris from 18 localities throughout its ecological and distributional range showed that concentrations and distribution patterns for each nutrient in fruits were similar, irrespective of soil type. It is concluded from the results for G. leucopteris and the other species that there is conservative genetic regulation of seed mineral nutrition in the genus Grevillea.
Pollination of Diuris maculata R Br (Orchidaceae) by Floral Mimicry of the Native Legumes Daviesia spp and Pultenaea scabra R Br
Authors: Beardsell DV , Clements MA , Hutchinson JF , Williams EG
Published: December 2005

Several species of insects captured while feeding on flowers of the legumes Daviesia virgata and D. mimosoides carried pollinia of the orchid Diuris maculata on their heads. In contrast, insects were difficult to capture on Diuris maculata due to the very low frequency and short duration of visits. More pollinaria were removed from the flowers than pollinia deposited. Pollen loads carried by insects bearing orchid pollinia were almost exclusively from Daviesia spp. and Pultenaea scabra. These data, together with the morphological similarity of the flowers of D. maculata to those of Daviesia spp. and Pultenaea scabra, indicate that the orchid attracts pollinators by floral mimicry.
Honeyeaters and the Pollination Biology of Banksia prionotes (Proteaceae)
Authors: Collins BG , Spice J
Published: December 2005

Honeyeaters such as Phylidonyris novaehotlandiae and Lichmera indistincta forage preferentially in regions of Banksia prionotes inflorescences where nectar and pollen are most abundant, removing pollen from freshly opened florets and transferring some of it to the stigmatic grooves of other florets on the same or different inflorescences. Each floret is protandrous, with pollen dispersal occurring during the first 4-8 h following initial presentation and significant esterase secretion by the stigma commencing after this phase has ended. Foraging by honeyeaters results in considerable pollen movement between florets on individual trees, although B. prionotes appears to be highly self-incompatible. Movement of honeyeaters and pollen between inflorescences on different trees occurs less frequently than between those on the same trees. Nevertheless, outcrossing leads to penetration of styles by tubes formed by pollen grains deposited in stigmatic grooves in some instances. Despite the small size and isolation of the population studied, the resultant level of follicle formation per infructescence, and percentage seed set, are greater than for most other Banksia species for which data are available.
Growth Rings, Age and Taxonomy of Dacrydium (Podocarpaceae) in Fiji
Authors: Ash J
Published: December 2005

The anatomy of growth rings in Dacrydium (Podocarpaceae) from Fiji is described. Fungal staining may mask the heartwood growth rings and generally prevents observation of rings on either roughly cut logs or sanded sections with the naked eye. Earlywood is formed during the wet season and coincides with a peak of leaf and shoot growth. Radiocarbon dating of three trees indicates that growth rings have an approximately annual frequency. The average trunk diameter growth rate is estimated as 2.6 mm year-1. Life expectancy of established trees is estimated as 49 year. It is suggested that the endemic species D. nausoriense de Laub. may be an ecotype of D. nidulum de Laub. adapted to the drier climate of north-west Viti Levu.
Demography and Production of Leptopteris wilkesiana (Osmundaceae), a Tropical Tree-Fern From Fiji
Authors: Ash J
Published: December 2005

The demography of Leptopteris wilkesiana (Osmundaceae) was studied in an area of undisturbed primary forest near Suva, Viti Levu, Fiji. The tree-fern has a single growth flush of 3-9 new leaves each wet season, and this is apparent as a distinct annual band of stipe scars on the trunk. Trunk ages ranged up to 133 years and trunk height growth averages 1.6 cm year-1. Leaf longevity is normally 2-2½ years. There was a 1% probability that a trunk would fall over, or be knocked over, each year; most trunks produced new roots at the lowest part of the fallen stem and continued growing. Sporangia production commenced in plants 30-45 cm tall and increased with leaf size and the number of leaves. Spore pro- duction ranged up to 17 x 106 spores year-1 on a large plant, and 3 x 108 spores year-1 for a population of 100 plants, while recruitment of sporophytes was estimated at 1 year-1.
Annual net production ranged up to 38 g oven-dry tissues on a large plant of which 55% was leaf production and 8% sporangia production.
Three Lichen-Forming Clavarioid Fungi From Tasmania
Authors: Petersen RH , Kantvilas G
Published: December 2005

Three species of Multiclavula are described from Tasmania, Australia. Two (M. vernalis, M. mucida) exhibit cosmopolitan distribution patterns, while the third appears to be new.
Grass Genera of the World: 728 Detailed Descriptions From an Automated Database
Authors: Watson L , Dallwitz MJ , Johnston CR
Published: December 2005

Three microfiches are presented, carrying detailed descriptions of 728 grass genera, produced from an automated database. The descriptions incorporate compiled data and original observations on over 300 morphological and anatomical characters, including copious original observations on leaf anatomy and features indicative of photosynthetic pathways and C4 types. A classification to subfamily and supertribal levels is appended to the generic descriptions. The organization, availability and potential applications of the computerized database are described.
Holocene Vegetation and Environments Near Goulburn, New South Wales
Authors: Dodson JR
Published: December 2005

Three sites from Breadalbane Basin and one from Wet Lagoon near Goulburn were studied to provide a history of vegetation, fire and lake levels in the region. Stratigraphy, a percentage pollen diagram from each site, an influx diagram from two sites and 29 radiocarbon analyses provided the basic data and chronology of the study. The sedimentary history shows that Breadalbane Basin has undergone several cycles of lake phases with sediment accumulation and dry phases with deflation of the lake sediments. The present lake clays and silts of Breadalbane Basin and Wet Lagoon are all Holocene in age. A lake began forming in Breadalbane Basin before 9300 B.P. and probably reached its greatest extent between 7400 and 2700 B.P. At Wet Lagoon water stands were in evidence from 5000 B.P. Over the last 2000 years the sites have dried out and are ephemeral swamps but their water level histories are not necessarily synchronous. A comparison of the records shows that the vegetation of the region has been open eucalypt woodland with understorey dominated by grasses and herbaceous taxa. The most dramatic change was woodland clearance after the arrival of European settlers. The spread of pollen and charcoal collection sites, however, emphasizes a number of local differences in the vegetation of the region. Casuarina, for example, expanded during the mid Holocene along the escarpment on the western side of Breadalbane Basin. The charcoal input curves show fire was a frequent occurrence in the region but the vegetation was apparently resilient to its effects until European settlers used it as a tool in woodland clearance.
Vegetation Changes Associated With Invasion by Phytophthora cinnamomi on Monitored Sites in the Grampians, Western Australia
Authors: Kennedy J , Weste G
Published: December 2005

The effects of invasion by Phytophthora cinnamomi were measured on sites representing the larger forest
regions of the Grampians. Changes were obvious at first, with the death of more than 50% of the species
including large plants such as Xanthorrhoea australis, but soon became dificult to detect as susceptible
species were replaced by field-resistant graminoids. Reductions were assessed in species heterogeneity
and plant density during 1976, at the onset of disease and from 1977 to 1984. Susceptible species
disappeared from infested forest and no re-emergence was observed. Less-susceptible plants such as
some Euca/yptus spp. declined in number, regeneration and size, due to deaths or dieback of the
branches. Reductions in tree canopy and the loss of structural dominants of the understorey caused
changes in the flora which are likely to persist. The survival of rare, susceptible endemic species may
be endangered.
On dry, steep slopes the dead plants were not replaced and the amount of bare ground increased
causing erosion of the soil surface. Some graminoid species increased in abundance on level, infested
sites, resulting in a different species composition but with both species heterogeneity and plant density
numerically similar to the previous flora.
Taxonomic Studies on Australian Isolates of Stemphylium spp. And Associated Teleomorphs
Authors: Irwin JAG , Dill-Macky R , Stirling M
Published: December 2005

Taxonomic studies on monosporic pure cultures of Australian isolates of Stemphylium revealed the
presence of three species, namely S. botryosum, S. globuliferum and S. vesicarium. A group intermedi-
ate between S. botryosum and S. vesicarium but more closely resembling S. vesicarium was recognised.
The circumscription of S. vesicarium was broadened to accommodate this taxon which was found on
Medicago sativa, M. rugosa and Simmondsia chinensis. Studies on herbarium specimens deposited as
S. botryosum on M. sativa from a number of overseas locations indicated that in all cases the pathogen
fitted our concept of S. vesicarium.
Teleomorphs were induced in pure culture for each of the above-mentioned anamorphs, and in all
instances the teleomorph was identified as Pleospora herbarum. The ascospore morphology was similar
for all isolates, and the shape of the ends of the spore and the number of longitudinal septa were variable
characters even within an isolate. However, the teleomorphs could be separated into two distinct groups
on the basis of ascal length.
Population Dynamics and Regeneration of a Hybrid Zone Between Eucalyptus risdonii Hook-F and E amygdalina Labill
Authors: Potts BM
Published: December 2005

Regeneration of a hybrid zone between E. amygdalina and E. risdonii and pure species stands following
wildfire is reported, as well as the reproductive and vegetative fitness of parental and hybrid phenotypes.
E. risdonii phenotypes dominated the seed rain and seedling cohort and there was clearly a marked
fitness differential between E. amygdalina and E. risdonii at their boundary. When the F1 type hybrid
is in competition with both parental types it is generally reproductively the least fit, although frequently
vegetatively vigorous. Reduced fitness appears to extend to advanced generations as hybrid phenotypes
tending.toward either species are, on average, less fit than the corresponding parental type.
The pattern of phenotypic fitness suggests that the species' boundary is in disequilibrium and it is
argued that E. risdonii is invading the range of E. amygdalina by both pollen and seed migration. There
is an asymmetric distribution of F1 type hybrids across the boundary and the hybrid swarm examined
is being invaded by E. risdonii genes. It is suggested that hybridization may be associated with natural
disequilibrium and, where seed migration is limited, boundary movements may be preceded by a wave
of hybridization due partly to pollen swamping of the least fit species. Hybrid swarms may develop but,
at the boundary of large stands, are probably transitory. There is a marked inertia in the population
response to the prevailing selective regime due to the extremely slow population turnover and limited
dispersal potential. This is discussed in the broader context of non-equilibrium models where it is argued
that dispersal may be the factor limiting population response to perturbation of a shallow environmental
gradient. This is due to large geographical shifts in the position of the null point and would be accentuated
in a patchy environment where migration as a front is prevented.
Origin of the Grampians Shining Peppermint ̵1 a New Subspecies of Eucalyptus willisii Ladiges, Humphries & Brooker
Authors: Newnham MR , Ladiges PY , Whiffin T
Published: December 2005

Adult morphology, seedling morphology and leaf volatile oil composition are described for a peppermint
eucalypt (Eucalyptus aff. willisin restricted to the Grampians, Victoria. Populations were compared with
E. willisii collected from Mt Richmond and Wilson's Promontory and the ash, E. pauciflora, collected
from the Grampians. Three data sets were independently analysed by using multivariate classification
and ordination techniques in order to test the hypothesis that introgression has occurred between
E. willisii and E. pauciflora in the Grampians.
The hypothesis of introgression was not supported. The Grampians peppermint is a uniform and
distinct entity which is not overall intermediate between E. willisii and E. pauciflora. It is typified by
large obconical fruit; adult leaves with low oil gland density and a distinctive leaf volatile oil composition;
and seedlings which display early intranode development, petiole formation and twisting, and
leaves with tapering bases.
The Grampians peppermint has probably evolved from a small founder population of E. willisii (or
a common ancestor) that has diverged in isolation. The presence of a few 'ash' characters in the
Grampians peppermint is here considered to be due to convergent evolution, in the direction of
E. pauciflora. The Grampians peppermint is described as a new subspecies.
Leaf-Area and Average Leaf Angle From Transmission of Direct Sunlight
Authors: Lang ARG
Published: December 2005

Previously, leaf area indices and mean leaf angles were obtained from measurements of the mean
transmissions of the direct beam at a range of sun angles by using a mathematical inversion. Results
of equivalent accuracy can be obtained more simply with graphical methods described here. The procedure
was tested with five hypothetical distributions of leaf angle and was applied to field measurements
of transmission of a sorghum crop.
Axillary Meristem Ontogeny in Araucaria cunninghamii Aiton ex D Don
Authors: Burrows GE
Published: December 2005

The presence of axillary meristems in apparently blank leaf axils from the main stem of 2-year-old
Araucaria cunninghamii is demonstrated. These meristems are groups of cells of meristematic appearance,
which possess neither a bud-like organisation nor vascular or pro-vascular connections with the
central vascular cylinder. They are first discernible in the axils of the recently initiated leaves, where each
meristem is delimited from the vacuolating cortex by a shell zone. The axillary meristems then persist
indefinitely in an inhibited, undifferentiated state, unless stimulated to bud formation by decapitation
of the terminal shoot apex. They are exogenous in origin but are subsequently buried beneath the stem
surface by the formation of localised periderms, the bark patches, and are not abscissed when extensive
periderm formation begins.
A. cunninghamii is apparently unique amongst conifers in possessing distinct, long-lived,
exogenously initiated meristems or bud primordia in macroscopically blank leaf axils. The meristems
are found in most leaf axils not occupied by branch buds. In this respect A. cunninghamii differs from
most conifers and approaches the typical condition of angiosperms. The axillary meristems are inter-
mediate in form between previously described vegetative axillary structures in gymnosperms and angiosperms.
A Conductivity Method for Screening Populations of Eucalypts for Frost Damage and Frost Tolerance
Authors: Raymond CA , Harwood CE , Owen JV
Published: December 2005

The assessment of frost tolerance of Eucalyptus leaf tissue by an electrical conductivity method is
described. Leaf disc samples were exposed to freezing treatments in test tubes within a liquid cold bath
with precise temperature control, and the conductivity of the disc leachate measured. Leaf discs were
then frozen at -20°C to obtain an absolute conductivity for the tissue. A modified relative conductivity
value (RC*) is presented together with calibration against visual observations of leaf damage for seedlings
of E. regnans and E. delegatensis. RC* was found to be a reliable indicator of leaf survival status
and the RC*-damage relationship was constant across provenances of both species.
Provenance and family variation for frost tolerance were examined for both species and significant
differences in tolerance levels were found for unhardened E. delegatensis and for hardened seedlings of
both species at several test temperatures. Provenance rankings were identical to results from field trials
reported in the literature.
The effect of the period between frost treatment and conductivity measurement was assessed together
with variation between leaves of the same plant and the effect of storage of cut leaves for 24 h prior
to exposure to frosting treatments. The absence of any significant effects from storing leaves for 24 h
indicates the potential of using the method to screen samples collected in the field. Problems of relating
RC*, leaf damage and survival of the whole plant are discussed and the potential use of RC* as a simple
screening technique for identifying frost-tolerant families and provenances is examined.
Eucalyptus Aromaphloia Pryor & Willis ̵1 a Redefinition of Geographical and Morphological Boundaries
Authors: Chappill J , Ladiges PY , Boland D
Published: December 2005

Adult and seedling morphological data collected for 37 populations referred to Eucalyptus aromaphloia
Pryor & Willis have been analysed using a range of multivariate classification and ordination techniques.
The analysis of adult leaf, bud and fruit morphology revealed only a subtle pattern of geographical
variation of limited diagnostic significance. Differentiation in terms of seedling morphology was more
marked, and four groups were identified. A relatively high incidence of character segregation in progeny
from individual trees was observed and.the implications of this are discussed.
Two of the four groups encompass seedlings with non-glaucous, narrow juvenile leaves and round
stems. The first group comprises populations from the Little Desert and the Grampian Ranges west of
the Mt William Range. The juvenile leaves are linear, sessile for many nodes and often become falcate
after 15-20 nodes. The second group is a single population from east of Rylstone, north-west of Sydney.
The juvenile leaves are lanceolate and become petiolate but not falcate after the 15th leaf node. This
population was previously referred to E. corticosa L. Johnson.
The third group is similar to the type of E. aromaphloia and populations were found only in west-
central Victoria, from the Mt William Range in the Grampians east to the Brisbane Range near Melbourne. Seedlings are characterised by round stems and ovate, glaucous juvenile leaves that are sessile
or subsessile for many leaf nodes. Thus E. aromaphloia s. str. has a more restricted distribution than
previously described.
The fourth group comprises populations from eastern Victoria where the juvenile leaves are non-
glaucous, broad-lanceolate, distinctly petiolate by the 11th node and the stems are often square.
Overgrowth of Pollen Tubes in Embryo Sacs of Rhododendron Following Interspecific Pollinations
Authors: Williams EG , Kaul V , Rouse JL , Palser BF
Published: December 2005

Frequent overgrowths of pollen tubes within the embryo sac are characteristic of a number of
interspecific crosses in the genus Rhododendron (Ericaceae). The combined techniques of sectioning,
squashing and whole-ovule clearing have confirmed that in ovules showing this phenomenon the pollen
tube fails to terminate growth and release sperms on entry into a synergid; instead it continues to grow
beyond the synergid and egg cell, often filling the main body of the embryo sac with a coiled and
distorted mass. Such ovules fail to develop further. The occurrence and possible causes of this error
syndrome are discussed.
A Postfire Chronosequence of Cone, Follicle and Seed Production in Banksia ornata
Authors: Gill AM , Mcmahon A
Published: December 2005

The fire-sensitive shrub Banksia ornata relies on seed stored in serotinous 'cones' for its regeneration.
Seed release takes place largely as a result of fire but a very small percentage of fruits may open
spontaneously. In a chronosequence studied in heaths of the Little Desert of north-western Victoria, we
found no seedling establishment in the absence of fire except in the oldest stand, dated at 50+ years
since fire. Seed quantity was low in stands 6-7 years old but rose to a peak in the 38-year-old stand.
The decline of seed quantity in the 50+ year-old stand was due to dieback and death of bushes. There
was no evidence for an increase in the proportion of seeds predated with age of stand. An average of
about 70% of the seed was regarded as 'intact' (no sign of damage) and about 80% of these seeds
germinated under ideal laboratory conditions. It was estimated that the amount of seed available for
regeneration increased with stand age up to 38 years but declined by 50+ years. It was suggested that
a period of 16 years without fire could be needed to achieve stand replacement of populations of this
species. The age at which full replacement can be achieved will vary, however, according to fire intensity
and seasonal weather conditions. Further quantitative research is needed.
Nodulation of Casuarinaceae in Relation to Host Species and Soil Properties
Authors: Reddell P , Bowen GD , Robson AD
Published: December 2005

A field survey was conducted in Australia to examine nodulation of Casuarinaceae in relation to 22 host
species (187 sites) and soil chemical properties (152 sites). Four of the five Casuarina species examined
were regularly nodulated (most plants in the 60 out of 88 sites in which nodules were found). Casuarina
species occurred more frequently on soils of higher available-phosphorus status than did Allocasuarina
species, eight of which did not nodulate in any soils. With the nine Allocasuarina species which nodulated,nodules occurred on only a minority of the individual plants examined. Soil chemical properties
other than available-phosphorus level were useful in distinguishing sites at which individual species
occurred but had no apparent relationship to nodulation.
Under glasshouse conditions, baiting of field soils with seedlings of Casuarinaceae indicated the
occurrence of nodulation to be similar to that observed in the field survey. Allocasuarina species formed
ectomycorrhizas more commonly than did Casuarina species; both genera formed vesicular-arbuscular
mycorrhizas. A second glasshouse experiment supported the hypothesis that low phosphorus supply and
the absence of infective Frankia were two of the factors responsible for the absence of nodulation in
some field soils. The effects of other soil factors in limiting plant growth and nodulation of
Casuarinaceae are considered, and the potential significance of N2 fixation by Casuarinaceae in the field
discussed. Nodules were found on Allocasuarina campestris, A. dielsrana and A. lehmanniana, not previously
recorded as nodulating.
Phosphorus Acquisition in the Soil-Root System of Eucalyptus pilularis Smith Seedlings. II the Effect of Ectomycorrhizas on Seedling Phosphorus and Dry Weight Acquisition
Authors: Heinrich PA , Patrick JW
Published: December 2005

Ectomycorrhizas were visible on Eucalyptus pilularis Smith seedling root systems 30 days after sowing
when seedlings were grown under glasshouse conditions in a severely phosphorus-deficient A1 horizon
soil collected from a study area in the Myall Lakes National Park, N.S.W. The types of ectomycorrhizas
were similar to those observed on seedlings collected from the study area. Black ectomycorrhizas were
the initial and dominant symbiont on seedlings until at least 6 months after sowing.
The ectomycorrhizal component of the A1 horizon soil could not be eliminated by partial sterilisation
of the soil without a significant change in the available phosphorus supply. However, a comparison of
seedlings grown in autoclaved soil with or without black ectomycorrhizas showed that this symbiont had
the capacity to increase the phosphorus acquisition of seedlings.
A correlative approach, quantifying the relationship between black ectomycorrhizal infection intensity
and seedling growth, was utilised to indicate whether the black ectomycorrhizas improved phosphorus
and dry weight acquisition of seedlings grown in A1 horizon soil. The pattern of phosphorus
acquisition and the dry weight increment of seedlings grown in the A1 horizon soil under glasshouse
conditions were characterised by two phases, the second indicated by a three-fold increase in both
seedling parameters 116 days after sowing.
At a harvest in the first phase of growth (96 days after sowing) seedlings with larger numbers of black
ectomycorrhizas per unit root length had significantly higher phosphorus contents (P< 0.05) but not
dry weights. In comparison, a harvest selected in the second phase of growth (176 days after sowing)
showed that both seedling phosphorus content and dry weight were highly correlated with the numbers
of black ectomycorrhizas per unit root length (r² = 0.81 and r² = 0.88 respectively). These results,
when considered in combination with the inoculation study, indicate that black ectomycorrhizas do
improve the phosphorus acquisition of seedlings grown in A1 horizon soil. The black ectomycorrhizas
increased the inflow of phosphorus by 2.2 x 10-6μg P cm infected root length-1 s-1. We propose that
dry weight was promoted by this increase only when substantial amounts of phosphorus were transferred
to the shoot. This has been shown to occur primarily in the second phase of seedling growth.
Sequential Flowering of Thistles (Cynareae, Asteraceae) in Southern Australia
Authors: Forcella F , Wood H
Published: December 2005

Flowering patterns of four and seven species of thistles were examined in Wagga Wagga, N.S.W. and
Canberra, A.C.T. respectively, during the 1982-83 and 1983-84 flowering seasons. Flowering patterns
at each location were sequential, consistent and differed significantly among species. The progression
of anthesis among the species was as follows: Carduus pycnocephalus, Silybum marianum, Onopordum
acanthium, O. illyricum, Centaurea calcitrapa, Carthamus lanatus and Cirsium vulgare.
Early-flowering species typically had brief flowering periods whereas later species flowered for con-
siderably longer periods. Seed (achene) dormancy patterns and optimum temperatures for germination
of the first and last species of the sequences were analysed. Seeds of C. pycnocephalus exhibited pro-
nounced innate dormancy for at least 2 months after seed maturation and germinated poorly at high
temperatures. In contrast, some seeds of C. vulgare were able to germinate soon after seed maturation
and over a wide range of temperatures. Early-flowering species probably benefit from pronounced
dormancy by avoiding precocious seed germination during wet springs, while high temperatures prob-
ably restrict germination after rare rainfall during the long and dry summers of Mediterranean-like
southern Australia. Such dormancy is unnecessary for late-flowering species in this environment as their
seeds are produced coincidentally with the onset of more reliable autumn rains.
Dormancy and Viability in Acacia suaveolens (Sm) Willd
Authors: Auld TD
Published: December 2005

Germination in A. suaveolens was controlled by a seed coat-linked innate dormancy, and scarification
was successful in breaking this dormancy in the laboratory. The tetrazolium test was a useful indicator
of potential germination capability. Such a baseline for germination is necessary before comparisons
between different pre-germination treatments can be validly attempted both inter and intraspecifically.
The onset of innate dormancy in the field occurs at the time of fruit ripening and most seeds are
dispersed in a state of innate dormancy (96 � 0.5%). This level of dormancy and a correspondingly
high level of viability (93.8 � 1.5%) are constant over time, space and plant age.