bluuebunny/crossref_metadata_2025 huggingface dataset:
Monolete, monocolpate, and alete sporomorphs from Australian Permian sediments
Authors: Balme BE , Hennelly JPF
Published: December 2005

Isolated monolete, monocolpate, and alete sporomorphs have been found to occur frequently in Australian coals and shales of Permian age. The structure, distribution, and possibie affnities of a number of the more common types have been discussed and an attempt made to classify the sporomorphs described on the basis of their germinal mechanism and ornament.

Seven new sporomorphs and one new form have been assigned to one or other of the existing sporotypes, Laevigatosporites Ibrahim, Tuberculatosporites Imgrund, Verrucososporites (Knox) Potonie & Kremp, and Entylissa (Naumova) Potonie & Kremp. Marsupipollenites n. spt, and Pilasporites n. spt. have been instituted as new sporotypes.
Species distribution over part of the Coonalpyn Downs, South Australia
Authors: Litchfield WH
Published: December 2005

An account is given of edapho-climatic ranges and species area of elements of the mainly sclerophyllous vegetation of a representative portion of the Coonalpyn Downs. Eucalyptus, Melaleuca, Acacia, Hakea, Leptospermum, Casuarina, and Callitris are the principal genera discussed. Water relations as governed by soil profile characteristics, landscape position, and the depth and salinity of water-tables are considered to be the main factors influencing plant distribution. The rainfall gradient across the area is gentle and rainfall as an independent factor only appears to influence water relations sufficiently to affect species distribution in a few cases. The fertility of soils on sandplain and sand dunes is invariably of a low order and a species composition typical of higher fertility soils is usually only found on inliers of such soils. Subsidiary edaphic responses include gross changes in soil reaction and soil salinity. A few indicator species in a given plant community can be associated with some particular soil characteristic and such correlations are distinct from community responses. For example, Hakea vittata in heath is generally associated with sandplain soils with a lime pan or a calcic subsoil within 2 ft of the surface. An examination of the area of numerous species shows that there is considerable variation across the territory in the composition of communities with repetitive dominants. Evidence is presented that suggests that species migrations may have spread from refuges or at least continuously vegetated areas within the territory as well as from outside it. The poor correlation between the area or limits of centres of frequency of some species and their observed edapho-climatic ranges suggests that migration is still occurring and that the climax community has not been produced in all cases.
The morphology of red beet (Beta vulgaris L.). Mitochondria
Authors: Farrant JL , Potter C , Robertson RN , Wilkins MJ
Published: December 2005

The morphology of mitochondria extracted from beet (Beta vulgaris L.) tissue was examined by phase contrast and electron microscopy and compared with the structure of mitochondria in tissue sections. The structure of the beet mitochondria proved much more labile than that of animal mitochondria and no really satisfactory way of preserving it was found. However, it was demonstrated that the organelles, which were either spherical or ovoid, were bounded by typical double membranes, presumably lipo-protein, about 170 Å thick. Internally the mitochondria contained
membraneous structures embedded in a finely granular matrix.
The analysis of point quadrat data
Authors: Kemp CD , Kemp AW
Published: December 2005

The type of distribution followed by point quadrat percentage-cover data has been studied. The hypergeometric type IIA distribution with constant n has been deduced from theoretical considerations and found to give a good fit to data published by Goodall in 1952. The parameters of this distribution assist the study not only of the overall percentage cover but also of the patchiness of the vegetation. The assumption of this type of distribution does not preclude the use of the angular transformation; this remains the appropriate transformation for stabilizing the variance. Theoretical considerations have been put forward in support of the policy of reducing the number of pins per frame. However, if this is done, the number of necessary locations is increased; only by practical experimentation can the optimum number of pins per frame be determined.
Contributions to Australian Bryology. I. The structure, development and systematic affinities of Monocarpus sphaerocarpus gen. et. sp. nov. (Marchantiales)
Authors: Carr DJ
Published: December 2005

A new thallose hepatic with characters intermediate between those of the Sphaerocarpineae (sensu Müller) and the section Caudiciformes of the Marchantiineae
has been discovered on saltpans in north-western Victoria. The female thallus bears a single spherical involucre which has air chambers and specialized pores and contains a single sporophyte. The male plants have not been found. Details are given of the structure and mode of development of the involucre, air chambers, and pores, the early embryogeny of the sporophyte, spore germination, and the development of the thallus. The systematic position of the new plant
(Monocarpus sphaerocarpus) is discussed and the literature on the relationship between the Sphaerocarpineae and other thallose hepatics is reviewed. The characters of Monocarpus are shown to support the view that phaerocarpus and allied genera should be placed within the Marchantiales rather than with the Jungermanniales. It is proposed to raise a new suborder of the Marchantiales, Monocarpineae, for the single genus, Monocarpus. Certain problems of morphogenesis are raised and it is suggested that the enciosure of more than one archegonium in an involucre is conducive to the inhibition of development of more than one sporophyte within the involucre. It is also suggested that growth substances released during meiosis in the sporangium control the post-fertilization growth
of the thallus and involucre.
The nature of surface growth in plant cells
Authors: Wardrop AB
Published: December 2005

Autoradiographs have been prepared from parenchyma isolated from Avena coleoptile segments grown in a medium containing labelled glucose. The autoradiographs
show that there is no concentration of radioactive material at the cell tips and labelled cellulose appears to be uniformly distributed in the cell wall. Electron micrographs of similar material show that the cellulose microfibrils are almost transversely oriented on the inner surface of the cell wall but are considerably dispersed from this direction on the outer surface. From this evidence it is concluded that growth in coleoptile parenchyma is not of the "bipolar" or
"mosaic" types previously suggested, but corresponds to the "multi-net growth" of Roelofsen and Houwink. In addition a study has been made of the relation of microfibril orientation to cell form in parenchyma of onion root and in roots after treatment with colchicine, from which it is concluded that the final microfibril orientation on the outer wall surface is determined by the extent and polarity of its surface growth.
The inheritance of wood and bark characters in Eucalyptus
Authors: Pryor LD , Chattaway MM , Kloot NH
Published: December 2005

Hybrids from segregating hybrid swarms have been examined in relation to the parents. Two series of hybrids were chosen, one derived from the combination E. robertsoni x E. rossii, of the group Renantherae, and the other from E. elaeophora x E. maculosa of the group Macrantherae-Normales. The hybrids and parents were assessed according to various physical and mechanical properties of the wood, features of bark structure, field characters, and measurements of characters in the progeny raised from each. The properties of the hybrids were found to be either not significantly different from those of either parent or intermediate between those of the two parents. The degree to which they approached either parent in the various phenotypic characters examined was found, in the few cases where data were adequate, to be correlated closely with the genotype and likewise with its position in the range between the two parents. The graded sequence of variation in the characters of the
different individuals in the hybrid combinations suggests those characters examined are, in general, under multiple factor control. It is likely that most Eucalyptus hybrids are intermediate as a, rule in their characters between the parents, and this applies to wood and bark characters as well as general morphological features.
Trilete sporomorphs from Australian Permian sediments
Authors: Balme BE , Hennelly JPF
Published: December 2005

This paper, in conjunction with two earlier publications by the same authors (Balme and Hennelly 1955, 1956), completes the taxonomic revision of a number of the common sporomorphs occurring in Australian Permian sediments. Twenty-six sporomorphs bearing triradiate tetrad scars are illustrated and described, the majority being assigned to existing genera of Palaeozoic fossil spores. Two new organ genera, Tholosporites n. spt. and Bascanisporites n. spt. have, however, been created to receive morphological categories differing from any previously described. A short discussion on the distributions and possible affinities of the sporomorphs treated is included.
The genus Codium (chlorophyta) in southern Australia
Authors: Silva PC , Womersley HBS
Published: December 2005

Fifteen species of Codium, five of which were previously undescribed, occur along the southern coast of Australia. Detailed descriptions and illustrations of all species are given, together with their distribution and notes on the habitat of each.
Eutypa armeniacae Hansf. & Carter, sp. nov., an airborne vascular pathogen of Prunus armeniaca L. in southern Australia
Authors: Carter MV
Published: December 2005

A newly described Ascomycete, Eutypa armeniacae Hansf. & Carter, is shown to give the symptoms associated with "gummosis" disease of Prunus armeniaca L. (common apricot) in southern Australia. Experimental evidence is produced to substantiate the hypothesis that E. armeniacae is the ascigerous stage of an imperfect Cytosporina sp, which has long been recognized as the causal organism of "gummosis", and that airborne ascospores of E. armeniacae are the only source of inoculum. Ascospores of this species are shown to be well suited to aerial dissemination over long distances.
A study of some soil properties in relation to the invasion of native pastures by Bothriochloa ambigua S.T. Blake
Authors: Moore cWE
Published: December 2005

Soil samples at 1-in. intervals to a depth of 6 in. were obtained from six paired stands of Bothriochloa ambigua S. T. Blake and of Danthonia spp. at each of three sites. Determinations of moisture equivalent, pH, and total nitrogen were made on all samples, organic carbon on the 07ndash;1 in. samples, and mechanical analyses on the 0–1 in., 4–5 in., and 5–6 in. samples. Significant differences were found between the soils of the two communities in moisture equivalent, organic carbon, and per cent. silt + clay at 0–1 in.; in pH at 0–1 in., 3–4 in., and 5–6 in.; and in total nitrogen at all depths except 4–5 in. The results are discussed in relation to the effect of B. ambigua on the soil and the possibility that certain soil conditions favour invasion of native pastures this species.
Dark Island heath (Ninety-mile Plain, South Australia). II. The effects of microtopography on climate, soils, and vegetation
Authors: Rayson P
Published: December 2005

The topography of the experimental area at Dark Island is described as a series of crescentic sand dunes formed under the influence of westerly winds and separated by undulating sandplain. Variation in the heath vegetation of the area in relation to topography was described by means of the varying densities of 12 representative species. These
densities indicated the individual growth tolerances of the vegetation components. One hundred and twenty-six quadrats sampled from different topographical positions were sorted into homogeneous groups by the method of positive interspecific correlation. The four resultant vegetation communities were located respectively on eastern dune slopes, western dune slopes, sandplain, and in scattered sites. Examination of soil texture, rainfall incidence, and average daily hours of direct sunlight in relation to topography showed that three microhabitats can be separated: namely, eastern and western dune slopes and the sandplain. Eastern dune slopes have the most favourable growth conditions, western the least favourable. Neither the vegetation communities nor the microhabitats could be sharply delimited. The gradual changes of soil and microclimate produced a varying but continuous vegetation pattern. This pattern depended on the growth tolerances of different species and probably also on interspecific competition for the more favourable growth sites.
Dark Island heath (Ninety-mile Plain, South Australia). III. The root systems
Authors: Specht RL , Rayson P
Published: December 2005

This paper describes the nature of the root systems of the most important members of the heath community. Several variations of tap-root and fibrous root systems were observed. Tap-rooted species were either shallow rooting (1–2 ft) or deep rooting (6 or more feet into the clay subsoil). Two variations of deep tap-rooted species were observed. The tap-root of one decays with age; the laterals of the other produce frequent sucker shoots. In all forms of the deep tap-rooted species an extensive lateral root system was developed within the surface 12 in. of soil — the organic A1 horizon; the tap-root and occasional secondary vertical descended, often unbranched, to the subsoil. The fibrous root system may arise from stem bases, rhizomes, tubers, or underground stocks (caudices). With the exception of underground stocks, which had extensive roots in the A2 and A3 to B horizons, the other forms of the fibrous root systems were confined to the A1 horizon. The marked concentration of roots in the organic A1 horizon was illustrated in dry weight–depth curves. Most of the roots in the A2, and A1 horizons arose from the caudex of Xanthorrhoea australis R.Br.; the remainder were vertical roots which passed directly into the subsoil from the deep-rooted species. About 70 per cent of the species recorded in the heath had morphological characteristics which enabled them to survive a fire and sprout from perennating buds buried under the surface of the ground. Thus, although the aerial organs of the heath were destroyed by fire, the root systems provided a reserve of food and nutrients for the regenerating heath. The dry weight of the root systems was therefore scarcely influenced by fire and thereafter steadily increased in the organic A1 horizon as the stand aged. The presence of root nodules on species of Leguminosae and Casuarinaoeae as well as of haustoria on Exocarpos sparteus R.Br. and Euphrasia collina R.Br. Is recorded.
The regeneration of severed pea apices
Authors: Gulline HF , Walker R
Published: December 2005

Successful graft unions between meristematic tissues have been made in apices of the pea, Pisum sativurn L. A technique for preventing desiccation of apices during and after the operations was developed. Apical segments ranging from about 200µ down to 50µ. in depth were successfully grafted back to their parent plant. The subsequent development of grafted apices was completely normal. These experiments show that a complete shoot can be regenerated from an apical segment less than one-thousandth of a cubic millimetre in volume, containing about 600 cells. This is smaller than any graft previously recorded.
Dark Island heath (Ninety-mile Plain, South Australia). V. The water relationships in heath vegetation and pastures on the Makin sand
Authors: Specht RL
Published: December 2005

Heath vegetation shows a major flush of growth during the mediterraneantype summer season, a time when calculations of the soil moisture storage by the techniques of Thornthwaite (1948) or Prescott, Collins, and Shirpurkar (1952) indicate that severe drought conditions should oocur. Monthly observations on the moisture status of the Makin sand under heath vegetation and, for comparison, under various pastures are therefore recorded. The problems of obtaining an accurate water balance-sheet for such a heterogeneous vegetation as the heath are discussed. Difficulties in the use of the various techniques for measuring soil moisture in sand, which has a low pF of 1.85 at field capacity, are enumerated. The following relationships were found between the evapotranspiration index (Itr = Etr / Ew0.75) and the available water (W). These data were calculated for 6 ft of sand.
(i) Heath vegetation (10–14 years old) log (2.4–Itr) = 0.420–0.0383 W
(ii) Heath vegetation (burnt) log (2.4–Itr) = 0.461–0.0380 W
(iii) Oenothera odorata Jacq. pasture log (2.4–Itr) = 0.395–0.0269 W
(iv) Medicago sativa L. pasture log (2.4–Itr) = 0.390–0.0270 W
(v) Ehrharta calycina Sm. pasture log (2.4–Itr) = 0.400–0.0339 W
From these equations the mean monthly quantities of rainfall which may be stored in 6 ft of sand under the various treatments described were calculated. Drought conditions are shown to occur in December and January, but are relieved in the later months of summer. Even if the stored moisture below 8 ft is considered, the soil moisture status would be expected to be just sufficient to maintain the vegetation in a "dormant" state, and yet the major growth of the heath vegetation occurs at this time. The calculated mean annual values of Itr range from 0.53 to 0.60 for these perennial communities. Close approximations to the actual soil moisture status can be obtained by substituting these values for K in Prescott's formula for potential evaporation, i.e. Etr = K x Ew0.75. Supplementary data on transpiration, growth, and the root systems of the pastures are also included.
Nature and distribution of rain-forests in New South Wales
Authors: Baur GN
Published: December 2005

Rain-forest has a discontinuous distribution along the coast and adjoining ranges of New South Wales, extending to altitudes of over 4000 ft. Four major subformations can be recognized, along with two other structural forms which may deserve subformation status. The subformations have been defined as tropical, subtropical, temperate, and dry rain-forest. Six floristic alliances and their associations are briefly described. For the widespread development of rain-forest an annual rainfall exceeding 60 in. is required, though rain-forest is found under much lower rainfalls in places favoured by the soil or topography. The Hernicyclia alliance (dry rain-forest) is found in areas showing a distinctly seasonal rainfall distribution, while the Nothofagus alliance (temperate rain-forest) requires cold and very moist conditions. The Castanospermum alliance occurs along creek banks, usually away from the main rain-forest patches, and the Cupaniopsis alliance is found close to the coast, apparently requiring wind-borne supplies of moisture and mineral nutrients for its development. The Argyrodendron (tropical) and Ceratopetalum (subtropical) alliances occur under similar climatic conditions in the north, but with the Ceratopetalum alliance restricted by competition to the less fertile soils. In the south of the State, where climatic sifting has removed many tropical rain-forest species, the Ceratopetalum alliance occurs on the richer soils. The discontinuity of the rain-forest distribution has been brought about by past climatic changes. Human influence has always restricted rain-forest spread, and since European settlement the area of rain-forest in New South Wales has been reduced by about half.
Morphological, anatomical, and physiological changes in the developing fruit of the Valencia orange, Citrus sinensis (L) Osbeck
Authors: Bain JM
Published: December 2005

Measurements of fruit radius and peel and pulp width, as well as determinations of fresh weight, dry weight, moisture content total and protein nitrogen content, and respiration rate were made throughout two growing seasons on Valencia oranges from the Gosford district of New South Wales. Soluble solids, sugar, and acid were also determined in the juice. Anatomical changes during development were investigated throughout one season. Development could be divided into three stages, corresponding with changes in growth rate and coinciding on a calendar basis in both seasons. Stage I varied in length according to the date of the blossom, but was completed by mid December. This was the cell division stage; by mid December cell division was completed in all tissues except the outermost cell layers. Increase in fruit size at this stage was mainly due to increased peel thickness. Stage 11, a period of very rapid growth from mid December to mid July, was the critical period for growth and was distinguished
as the cell enlargement period, rapid morphological and physiological changes occurring in the absence of cell division. The growth of the pulp was responsible for most of the increase in fruit size during Stage 11; the peel reached a maximum width early in this stage and then became thinner with very little subsequent change in thickness as the pulp continued to increase in size. Stage 111, the maturation period, lasted from mid July until the fruit was ripe, or approximately 7 months. Fruit continued to grow for as long as it was left on the tree but at a very reduced rate
compared with Stage 11. Ripening occurred during Stage 111.
Thismia rodwayi F. Muell. and its endophyte
Authors: McLennan EI
Published: December 2005

The morphology of Thisrnia rodwayi — a holosaprophytic plant belonging to the Burmanniaceae — is described, together with an account of its associated mycorrhiza. Evidence is presented of the liberation of an osmic-staining fat from the fungal hyphae into the cells of the higher plant. Subsequently these globules disappear and are replaced by a complex polysaccharide resembling glycogen. The appearance of osmic acid-staining globules in the lumen of the cells and their ultimate disappearance is shown to be a phenomenon common to the complete saprophyte and to green mycorrhizal plants. It is, therefore, unrealistic to suggest that this arbuscular type of mycorrhiza should be interpreted as an example of parasitism, as is so often the case in the relevant literature.
Diploid and tetraploid Casuarina littoralis Salisb. (Syn. C. suberosa Ott. & Dietr.)
Authors: Barlow BA
Published: December 2005

Within the species Casuarina littoralis there are diploid and tetraploid forms,
having 22 and 44 chromosomes respectively. Previous records of 2n = 48 are
erroneous. The tetraploid form has an almost continuous distribution in eastern
Australia and Tasmania, whilst the diploid has a small, distinct distribution in
New South Wales and Queensland. Under certain conditions hybridization has
oocurred.
Changes in cell wall organization resulting from surface growth in parenchyma of oat coleoptiles
Authors: Wardrop AB , Cronshaw J
Published: December 2005

The primary walls present during the phase of extension growth in oat coleoptiles possess an almost transverse microfibril orientation on their inner surfaces but on the outer surface the microfibrils are considerably disoriented from this direction, which is consistent with the concept of multi-net mechanism of growth. Coleoptile segments grown at 2°C to depress cell wall formation show no difference in orientation on their inner and outer surfaces; this is also considered to be consistent with the multi-net mechanism. It is shown that the longitudinal ribs of microfibrils present at the cell corners, and hitherto referred to as secondary thickening, are on the outer surface of the cell wall and are considered to arise from a disorientation of microfibrils as a result of multi-net growth. As a result of this microfibril disorientation there is a tendency for the pit fields to be reduced in area. After surface growth has ceased a secondary wall is formed with a well-defined helical organization distinctly different from that of the primary wall. The implications of these results in terms of previous investigations are discussed.
Bud development and lignotuber formation in eucalypts
Authors: Chattaway MM
Published: December 2005

The minute structure of lignotubers is described and their development studied from their earliest inception in the cotyledonary and lower leaf nodes. The structure of the bud components of the leaf and cotyledonary nodes of tubering and non-tubering species has been compared. Lignotubers can only develop in species in which concealed buds are present above as well as below the axillary buds. Other factors may, however, inhibit their development even when the necessary buds are present.
Studies on the origin, evolution and distribution of the Gramineae. I. The tribe Andropogoneae
Authors: Hartley W
Published: December 2005

From a study of the grass flora of some 300 regions, a world distribution map of the grass tribe, Andropogoneae, has been prepared. This map shows that the Indo-Malaysian region is relatively rich in species of the tribe, with zones of high concentration in western India and in southern Indonesia. The relative species density falls off rapidly in passing from the tropical to the temperate zones, and is lower in the western than in the eastern hemisphere. Climatic factors are of major importance in determining the distribution pattern. Winter temperatures are of special significance in temperate regions, while there is a striking relationship between high midsummer rainfall and relative abundance of species of Andropogoneae in the tropics and subtropics. In general, the geographical survey supports conclusions drawn from taxonomic and cytological evidence regarding the origin and evolution of the tribe, but with greater emphasis on climate as a significant factor. The Andropogoneae have had a long evolutionary history in the eastern hemisphere, but have spread more recently to the western hemisphere, where they have not yet attained their full development.
The ecology of Eucalyptus regnans F. Muell.: the species and its frost resistance
Authors: Ashton DH
Published: December 2005

The distribution, habit, and variation in Eucalyptus regnans F. Muell. are briefly described. It is shown that E. regnans almost certainly forms hybrids with E. obliqua. The seedlings of E. regnans are relatively frost-sensitive, and this sensitivity is increased by manuring with organic nitrogen. Under artificial frost, softened seedlings are killed at temperatures below 25–27°F, whilst well-hardened seedlings are killed at temperatures below 20–22°F. In the field the lethal frost temperature is some degrees lower. Ecoclines exist in the E. regnans populations in south-central Victoria. The seedlings show a gradation in both frost resistance and growth rate along altitudinal gradients. Seedlings derived from trees growing at the edge of a frost pocket at Wallaby Creek (2000 ft) combine a relatively high frost resistance (equal to that of
seedlings at 3'700 ft) with a high growth rate.
Two species of subterranean clover in Israel
Authors: Zohary D , Katznelson J
Published: December 2005

Cytological and morphological study of subterranean clovers in Israel has shown that the previously reported 2n = 12 Israeli "chromosomal race" or "cryptic species" is actually morphologically quite distinct from 2n = 16 Trifolium subterraneum L. Both on morphological and genetical grounds the "Israeli race", with chromosome number 2n = 12, should be regarded as a distinct species. It is described in the present paper as a new species, Trifolium israeliticum. The paper includes data on the distribution of the two subterranean clovers in Israel.
The gametophyte and embryo of Polyphlebium venosum (R. Br.) Copeland (Hymenophyllaceae)
Authors: Stone IG
Published: December 2005

An account is given of the spore, its germination, the delicate filamentous prothallus, the reproductive organs, the embryo, and the young sporophyte of Polyphlebium verzosum.
The characteristic germination, which is a modification of the four-celled or Trichomanes type, remains unchanged under various conditions. A rhizoid appears first, followed after several weeks by a filament cell. The symmetrical four-celled stage is not attained, but after 3 months another rhizoid or filament cell is often cut off from the primary cell. The monoecious gametophyte is a branching uniseriate filament and bears numerous, small, stalked antheridia, each with a simple wall, and an operculum which is raised or shed to allow the spermatozoids to escape. The archegonia, with straight necks, and tiers of four to six neck cells, are borne on special structures, the archegoniophores. The prothallus reproduces itself vegetatively by regeneration, and by gemmae which on germination produce rhizoids, filaments, and antheridia or more gemmae. The embryo is the first described for the Trichomanes group, and the investigation showed it to be unusual. There is no primary root, a single archegoniophore may bear more than one embryo, and the axis of the embryo varies in its position relative to the neck of the archegonium, possibly because the archegonia are borne in various positions on the archegoniophore. The suggestion is made that the embryo develops in a manner which gives the foot as large a contact as possible with the
source of food supply. The gametophyte and embryo show some primitive characters, but the most conspicuous feature is specialization in the form of reduction as an adaptation to a
moist and shady environment. A key to the Victorian Hymenophyllaceae is appended.
Floral histogenesis in the monocotyledons. III. The Juncaceae
Authors: Barnard C
Published: December 2005

An account is presented of floral histogenesis in Luzula campestris (L.) DC., Juncus articulatus L., and Juncus vaginatus R. Br. The pattern of floral histogenesis in these species is similar to that in species of the Gramineae and Cyperaceae. Bracts, bracteoles, perianth members, and carpellary tissue arise by divisions of cells of the tunica. Periclinal divisions in the outer tunica layer (dermatogen) always occur in the initiation of these "foliar" type organs. The primordia of inflorescence branches, flower primordia, and stamens, on the other hand, arise as a result of cell division in the outer layers of the corpus and
the inner layer of the tunica. Periclinal divisions in the dermatogen are not involved in the differentiation of these "cauline" type structures. The morphological nature of the placentas in Juncus is discussed; they appear to arise independently of the carpellary tissue and after the manner of "cauline" structures. The ovules in both Luzula and Juncus arise in similar fashion.
The statistical study of plant distribution patterns using a grid of quadrats
Authors: Thompson HR
Published: December 2005

The statistical theory of the method of analysis of variance on a grid of contiguous quadrats is examined and the results from theoretical models for plant communities giving rise to non-randomness in the field discussed. Some field data are analysed and the theoretical and practical results correlated to determine the efficiency of the method as a practical technique. The large element that chance variation plays in practice makes it essential for several samples of the same community to be taken so that real and chance effects can be distinguished. A knowledge of the morphology of the species under consideration is desirable, for then some idea of the expected analysis of variance is available and there should be no confusion between different models.
Studies on the origin, evolution, and distribution of the Gramineae. II. The tribe Paniceae
Authors: Hartley W
Published: December 2005

A world distribution map of the tribe Paniceae has been prepared, based on the percentage frequency of species of Paniceae in the total grass flora of each region. The map shows that relative specific differentiation is higher in the western hemisphere than in the eastern hemisphere, and that there is a zone of maximum concentration in north-eastern South America. The significance of this distribution pattern is discussed, and it is shown that the taxonomic evidence does not support a New World origin for the tribe. The distribution of the Paniceae in the United States shows a close relationship to winter temperature, and especially to annual rainfall. These climatic factors are also of major importance in other parts of the world, and in large measure explain the present distribution of the tribe. The Paniceae and Andropogoneae both appear to be "natural" tribes, which probably originated from a common panicoid stock in the warmer parts of the eastern hemisphere, possibly in the East Africa–Madagascar region. The Paniceae spread rapidly throughout the tropics and subtropics of both hemispheres, especially in the equatorial zone with high temperatures and well distributed rainfall. They show a pattern of climatic adaptation differing from that of the Andropogoneae. The latter, apparently formed more recently from the panicoid stock, reach their highest development in monsoonal climates with a much shorter season of heavy rainfall.
Morphology and physiology of germination of Chara gymnopitys A. Braun. I. Development and morphology of the sporeling
Authors: Ross MM
Published: December 2005

A study has been made of the germination stages and development of the protonema of Chara gymnopitys A. Braun. The development of this Australian species is compared with that previously described for European and Indian species of the Charales. A detailed account of the sequence of cell divisions prior to the first division of the apical cell of the adult plant is given. The dorsiventral development of the protonemal filament and of the "shoot" is noted. The resulting dorsiventrality of the mature plant is discussed. The development and structure of the rhizoids is compared with that of the "stem" portion of the plant. A technique for collecting and germinating Chara spores under sterile conditions is fully described.
The ecology of the Bogong High Plains. I. The environmental factors and the grassland communities
Authors: Carr SGM , Turner JS
Published: December 2005

The paper is the first of several to present the results of a study, over the last 12 years, of alpine vegetation of the Bogong High Plains (north-eastern Victoria, 5400–6200 ft elevation). Attention is focused on the grassland communities and the response of soils and vegetation to the exclusion of cattle grazing. The first paper outlines the problem, briefly describes the major grasslands, and discusses the climatic and biotic factors concerned.
The ecology of the Bogong High Plains. II. Fencing experiments in grassland C
Authors: Carr SGM , Turner JS
Published: December 2005

A 10-year fencing experiment in the eroded grassland, type C, of the Bogong High Plains has established the value of the point analysis method for the quantitative study of continuing change in vegetation. The results show that the exclusion of cattle from this widespread type of subalpine grassland results in a gradual improvement in the amount of vegetative cover, especially in that provided by the herb Celmisia. Over the 10-year period there have been striking soil changes in the fenced plot, resulting in an increase in organic matter and in field capacity, and a significant decrease in bulk density. These findings enable one to make recommendations on catchment management in this area. They have also led to the hypothesis that the eroded grassland has been derived from a herb-field similar to that still existing in the higher parts of the area.
A contrast in the opal phytolith assemblages of two Victorian soils
Authors: Baker G
Published: December 2005

A statistical analysis of the assemblages of opal phytoliths in two Victorian soils of different origin, occurring approximately 90 miles apart and supporting generally different plant communities, reveals that some shape types of the phytoliths are common to both soils, while significant differences occur in the amount and nature of other shape types. The general conclusion is that the phytoliths in soil from basaltic tuff on the summit of Mt. Gellibrand in the Western District derive from the local plant population; those in alluvial clay soil developed under swampy conditions at Dalmore, Koo-wee-rup Swamp, derive largely from the local swamp vegetation, with the possibility of the introduction of certain shape types from different plants supported on the southern Dandenong Ranges 18 miles to the north, and on intervening areas. Transportation into the swamp lands would have been effected by the watercourses flowing in from the north, once the phytoliths had been released from plants and shed into the soils near the watercourses. It is doubtful whether any significant proportion of the phytoliths was wind-borne into either of the soils examined.
Control of water movement by stem chilling
Authors: Johnston RD
Published: December 2005

Apparatus is described whereby a portion of the stem of a young tree of Pinus radiata D. Don could be maintained at a temperature close to freezing point, while the transpiration of the upper part of the plant was measured. The freezing point of the stem was shown to be about -2°C, and while the stem temperature was kept above this point transpiration continued normaiiy; freezing the stem resulted in a decrease in transpiration, after a short lag period, and within 3 hr transpiration was almost undetectable. When the stem temperature was maintained at just below the freezing point for 7 days, the leaf water deficit of the shoot rose from 10 to 47 per cent., but returned to normal values within 4 days after freezing was stopped; the plant showed no signs of damage due to freezing. Field trials, using solid carbon dioxide as a refrigerant, showed that growth was reduced considerably on a branch chilled to -4°C for 7 days, but needles remained alive and appeared healthy. Lower temperatures caused damage to needles and twigs.
Developmental morphology of the floral organs of Eucalyptus. I. The inflorescence
Authors: Carr DJ , Carr SGM
Published: December 2005

The nature and structure of the inflorescenoe of Eucalyptus is re-defined in the light of an analysis of the unit inflorescenoe, its development, mode of branching, bract systems, and the grouping of unit inflorescences into compound inflorescences. The structure of the unit inflorescence in 80 representative species is elucidated and a systematic notation for expressing the numbers and arrangement of the involucral bracts in dichasial inflorescences is proposed. The infloresoence bud of Eucalyptus is generally asymmetrical in side view and often also in face view. External asymmetry is largely a result of the asymmetry of the outermost pair of bracts, by which the developing inner bracts and flowers are at first tightly enclosed, and may be reflected in an asymmetrical pattern of branching within the inflorescence. The asymmetry and pattern of branching are reflections of morphological features peculiar to the shoot system of Eucalyptus. The outer bracts resemble the adult leaves in their asymmetry about the midrib. The leaf and bract primordia arise decussately at the shoot apex but in most species the leaves of each pair become separated by the development of a segment of axis (an "intranode") between them. In certain species the development of an intranode between the outer pair of bracts leads to the splitting apart or "disarticulation" of the unit inflorescence into two subclusters. The very complex inflorescence of E. camaldulensis arises by disarticulation of a simple inflorescence, followed by interpolation, in a centripetal manner, of additional bracts and flowers between those first formed. Flower
numbers in clusters at successive nodes of the annual shoot may vary, rising with node number if the inflorescences are basitonically disposed, falling if acrotonically disposed. Flower number in successive clusters is correlated with other quantitative features of the annual shoot. The position and number of the inflorescenoe buds on the annual shoot and the interval between flower initiation and anthesis are characteristic of species and of groups of species. Phylogenetic trends in inflorescence characters are discussed. Inflorescences with few flowers and with free persistent bracts, the number of which is related to the flower number in the cluster, are held to be primitive. Inflorescences with many flowers, fused bracts constituting a caducous involucre in which the number of bracts is not related to the number of flowers, are held to be advanced. These and other charaoters of the infloresoence are shown to have taxonomic significance and their use is typified in an analysis of the infloresoence characters of the Renantheroideae in relation to those of the Renantherae.
The stratigraphy and history of Groenvlei, a South African coastal fen
Authors: Martin ARH
Published: December 2005

Borings on the fen at Groenvlei show that the earliest sediment was a diatomaceous nekron mud in a small freshwater lake. This filled in and fen peat formed over it. Subsequently, marine mud was spread over almost the whole basin, the course of the transgression being followed by diatom analysis. A change in composition of the marine diatom flora, apparently due to an unexplained change of temperature of the sea, is recorded. The marine incursion graded into brackish lagoon stages, towards the end of which conditions were rather unfavourable to diatom growth, followed by increasingly freshwater conditions, during which calcareous muds were laid down. The eastern basin of the lake became more or less separated from the main lake by a sand bar. The calcareous lake mud was overgrown by the latest reedswamp and sedge fen. Radiocarbon dating gave an age of 6870 years for a sample from the upper part of the submerged peat bed at Groenvlei, and a lapse of little under 5000 years before freshwater deposits again occupied the eastern basin of the lake (14C age of gyttja sample, 1905 years). This dating of the Groenvlei transgression is compatible both with the main post-Glacial eustatic rise of sea-level in the North Temperate latitudes, and with similar transgressions on the coasts of south-eastern Australia, New Zealand, and Fuego–Patagonia. The maximum height of the sea-level is considered to have been about 1.5 m higher than at present.
Gastrodia sesamoides R.BR. and its endophyte
Authors: McLennan EI
Published: December 2005

The anatomy of the tuberous rhizome of Gastrodia sesamoides R.Br., particularly in relation to the occurrence and detailed structure of its endophyte, is discussed and illustrated. This single Australian species resembles those other species (mainly tropical) that have been described in surviving as a saprophyte by the so-called "digestion" of its fungal symbiont. This takes place in a specialized layer of the cortex, and not, as has previously been thought, by an association with nitrogen-fixing bacteria.
Chromosome numbers in the Casuarinaceae
Authors: Barlow BA
Published: December 2005

Chromosome numbers of 37 species of Casuarina are reported, and found to conform with a suggested division of the genus into major species groups. The extra-Australian species groups are probably ancient, and are at the primary diploid level of the genus (x = 8 or 9). Somatic chromosome numbers ranging from 28 to 20 occur in the Australian stocks, and chromosome evolution has possibly involved an ancient polyploidy, followed by stepwise reduction in number. Later evolution in the distyla species group has involved no changes in the haploid chromosome number (n = ll ) , but polyploidy within the species has been frequent.
Polyploidy and apomixis in the Casuarina distyla species group
Authors: Barlow BA
Published: December 2005

In the Casuarina distyla species group, which includes 13 closely related species, sexual tetraploid forms have been recorded in nine species and apomictic triploids in four. These forms are probably autopolyploids. The triploid apomiots are presumably diplosporous and parthenogenetic, and in two species are pseudogamous, but not in the other two. It is suggested that a transition from the former to the latter breeding system would follow elimination of the need for pseudogamy. A hypothesis is presented that polyploidy and apomixis have arisen together within the species through establishment in a diploid population of a triploid plant which is diplosporous and parthenogenetic. The genetic system involved probably
spread through the group during the evolution of the species, giving them a potential for this kind of development.
Factors affecting growth and distribution of kauri (Agathis australis Salisb.) III. Effect of temperature and soil conditions
Authors: Bieleski RL
Published: December 2005

Kauri (Agathis australis) seedlings were grown under controlled conditions of temperature, soil moisture, and exposure to mycorrhizal infection. High temperatures inhibited root growth; seedlings exhibited a growth optimum at 23–26°C; the evidence suggested that both trees and seedlings were dormant when the maximum temperature fell below 17°C. Seedlings were generally resistant to both waterlogging and drought: waterlogging caused a decrease in root length and branching, but did not affect the root weight; drought increased root development at the expense of the stems. In the field, seedlings were liable to be killed by drought in the first few months of growth. The "high light intensity limit" to seedling establishment previously observed in the field was apparently caused by greater solar
radiation increasing soil desiccation during this critical period. Seedlings grown in sterile soil and those exposed to mycorrhizal infection showed no significant differences. The autecology of kauri is discussed in the light of current knowledge. The altitudinal and latitudinal limits could be caused by temperature limiting the rate of growth and also the length of the growing season. Kauri appears to occur preferentially on ridge-top sites because of its tolerance of poor soils and its resistance, once established, to drought. The inability of kauri seedlings to establish under
cover of the mature tree is thought to be caused by root competition effects. Kauri is no longer regarded as a seral stage in the development of a hardwood climax, but as one component of a "regeneration complex".
Callitriche in New Zealand and Australia
Authors: Mason R
Published: December 2005

A revision of Callitriche in New Zealand and Australia shows that 13 species (one with two subspecies) occur in these countries, of which C. capricorni (Queensland), C. petriei (New Zealand), and C. aucklandica (Auckland Is.) are new. C. palustria L. (syn. C. verna L.) occurs in Victoria only, not as hitherto recorded in New Zealand and widely in Australia. C. stagnalis Scop. and C. hamulata Ktzg. are adventives in Australia and New Zealand, and C. heterophylla Pursh emend. Darby in New Zealand. C. petriei subsp. petriei is the first dioecious taxon found in the genus.
The Australian species referred to Ichnanthus Beauv. (Gramineae)
Authors: Lazarides M
Published: December 2005

The opinion is expressed that the genus Ichnanthus Beauv. is represented in Australia by only one species, I. Vicinus (Bail.) Merr. It is proposed to re-establish in Panicum L. three species currently referred to Ichnanthus and transfer to it Ichnanthus muelleri Hughes. A revised account is given of the species concerned as to taxonomy, distribution, and economics.