Spinulosa Var Research Articles

A revision of the Miconia ulmarioides complex (Melastomataceae: Miconieae)

A taxonomic revision is presented for ten species that comprise the Miconia ulmarioides complex (Melastomataceae: Miconieae). This group is characterized by four-merous flowers with four-locular ovaries, short, stout, pink to fuchsia anthers, punctiform or truncated styles and short outer calyx teeth. All species in the group are small trees and shrubs from the northern Andes in Colombia and Venezuela and the Sierra Nevada de Santa Marta and Coastal Cordillera of Venezuela, with one species (M. nubicola) endemic to Jamaica. Leandra ossaeoides is transferred to Miconia (as M. ossaeoides) and M. albertii is synonymized under M. ulmarioides. We designate new lectotypes for M. arbutifolia, M. spinulosa, M. inaperta, M. octoscenidium, M. spinulosa var. subintegrifolia, M. ulmarioides, M. aegrotans, and M. ulmarioides var. fendleri. Descriptions, morphological discussions, key to taxa, and photographs of key features are included for all species.

Reproductive trajectories over decadal time-spans after fire for eight obligate-seeder shrub species in south-eastern Australia

Intervals between fires are critical for the persistence of obligate-seeding shrubs, and are often used in planning fires for fuel reduction and biodiversity conservation in fire-prone ecosystems worldwide. Yet information about the trajectories of reproductive performance for such species is limited and information is often qualitative. To test existing assumptions about reproductive maturity periods for eight obligate-seeding shrubs (with both canopy and soil seedbanks) in foothill forests of south-eastern Australia, we used a chronosequence approach, with sites from 2 years to >40 years post-fire. Quantitative measurements of flowering and fruiting were used to fit models of reproductive response in relation to time-since-fire for each species. Inferred reproductive maturity for each species, based on modelled times to reach 80% of maximum flower production, varied from 5 to 18 years post-fire. For a subset of three species, models predicted 80% maximum seed production occurring 1–7 years later than flowering. Our results confirmed or extended assumptions about post-fire reproductive maturity for these species, and provided a basis for improved incorporation of plant life-history in ecological fire planning. We infer that increased fire frequency makes one of our study taxa, Banksia spinulosa var. cunninghamii (Sieber ex Rchb.) A.S.George, vulnerable to decline because of its long reproductive maturity period and serotinous seed storage.

First instalment in resolution of the Banksia spinulosa complex (Proteaceae): B. neoanglica, a new species supported by phenetic analysis, ecology and geography

Taxa in the Banksia spinulosa Sm. complex (Proteaceae) have populations with sympatric, parapatric and allopatric distributions and unclear or disputed boundaries. Our hypothesis is that under biological, phenetic and diagnosable species concepts that each of the currently named taxa within the Banksia spinulosa complex is a separate species. Based on specimens collected as part of this study, and data recorded from specimens in six Australian herbaria, complemented by phenetic analysis (semi–strong multidimensional scaling and UPGMA clustering) and a detailed morphological study, we investigated both morphological variation and geographic distribution in the Banksia spinulosa complex. All specimens used for this study are held at the N.C.W. Beadle Herbarium or the National Herbarium of New South Wales. In total 23 morphological characters (11 quantitative, five binary, and seven multistate characters) were analysed phenetically for 89 specimens. Ordination and cluster analysis resulted in individuals grouping strongly allowing recognition of distinct groups consistent with their recognition as separate species. Additional morphological analysis was completed on all specimens using leaf, floral, fruit and stem morphology, providing clear cut diagnosable groups and strong support for the recognition of Banksia spinulosa var. cunninghamii and Banksia spinulosa var. neoanglica as species.

Genetic tests of the isolation of rare coastal dwarf populations of Banksia spinulosa

In southern New South Wales, a suite of widespread plant species exhibit short-statured ‘dwarf’ growth forms on coastal headlands. It is unclear whether such populations are genetically distinct or whether dwarfism is a plastic response to the environment. We used four microsatellite markers to assess genetic differentiation among populations from coastal and inland sites for Banksia spinulosa var. spinulosa. We sampled plants from six locations, including from three ‘dwarf’ and three ‘normal’ populations. Mean levels of genetic diversity were slightly higher in the forest (Na = 7.07 ± 0.25; He = 0.80 ± 0.09) than on the coast (Na = 5.92 ± 0.70; He = 0.72 ± 0.10). In general, populations displayed genotypic diversity expected for outcrossed sexual reproduction, with 161 of 172 individuals displaying unique genotypes and mean values of FIS close to zero. However, we found evidence of at least limited clonal replication in each of four populations and, within one coastal population, 11 of 27 individuals displayed one of three replicated genotypes, implying that the effective population size may be considerably smaller than would be inferred from the number of plants at this site. Relative to studies with other Proteaceae, this set of populations showed low, although significant, levels of differentiation (global FST = 0.061; P < 0.001), with extremely low, although significant, divergence of forest and coastal populations (FRT = 0.009; P < 0.001). There was no evidence of isolation by distance. These data imply that coastal dwarf populations are genetically similar to more extensive inland populations but in at least one case, may be at a greater risk of extinction because of low effective population size.

Evaluation of Banksia species for response to Phytophthora infection

Phytophthora cinnamomi was the species isolated most frequently from soil associated with dead or dying proteaceous plants in the Adelaide region of South Australia. The association of P. citricola with diseased Banksia species in South Australia is reported for the first time. The response of a range of Banksia species to inoculation with P. cinnamomi and P. citricola was assessed. P. cinnamomi was generally more pathogenic than P. citricola. Inoculation of 10‐month‐old seedlings with colonized millet seed or zoospores showed that B. hookeriana and B. ashbyi were the most susceptible of the species tested, whereas B. coccinea, B. menziesii and B. prionotes were moderately susceptible. B. ericifolia, B. serrata, B. spinulosa var. collina and B. lemanniana showed tolerance. Similarly, 2–3‐week‐old seedlings of B. ericifolia, B. serrata and B. spinulosa var. collina inoculated in vitro showed little disease 6 and 12 days after inoculation, whereas B. baueri, B. baxteri, B. coccinea and B. solandri, as well as B. hookeriana and B. ashbyi, showed severe symptoms of disease after 6 days. Results suggested that the in vitro assay may have potential in the evaluation of breeding material. Development of infection was studied microscopically in 2–3‐week‐old seedlings of B. coccinea, B. menziesii, B. serrata and B. spinulosa var. collina inoculated in vitro with zoospores of P. cinnamomi. Roots of B. coccinea and B. menziesii were colonized rapidly and root tips became necrotic within 24 h and hypocotyls by day 5. Penetration was delayed in B. spinulosa var. collina, and callose deposition was delayed in B. coccinea. Necrosis of roots of B. serrata and B. spinulosa var. collina began 3 days after inoculation but rarely extended more than half way up the root by 9 days.

Nonrandom Patterns of Fruit Set in Banksia spinulosa (Proteaceae): Interovary Competition Within and Among Inflorescences

In Banksia spinulosa var. neoanglica (Proteaceae) not all flowers and inflorescences are equally likely to produce fruit. Fruit set is low on the apex of inflorescences, and most inflorescences with small supporting stems do not produce fruit. Resource limitation was examined as a possible determinant of this fruiting pattern. All flowers had two apparently functional ovules, indicating that B. spinulosa is not andromonoecious. Ovules from the apical third of inflorescences were smaller than ovules from the mid and basal thirds of inflorescences. Also, ovule size decreased with decreasing stem diameter of inflorescences. However, small ovules were fertile. Experimental removal of flowers from the basal one-third and two-thirds of inflorescences increased fruit set of apical flowers by 71% and 152%, respectively. Similarly, fruit set of inflorescences with small stems increased twofold when inflorescences with large stems were prevented from producing fruit. These results indicate that resources can be reallocated both within and among inflorescences and that fruiting patterns are primarily a consequence of interovary competition occurring at both these levels. Anatomical constraints may also be important because the increases in fruit set in the experimental treatments did not completely compensate for the flowers and inflorescences that were removed. Low fruit: flower ratios in B. spinulosa may allow plants to increase reproductive output when nutrients are abundant and to compensate for the effects of floral predators.

Variation Between Years in Pollen and Nutrient Limitation of Fruit-Set in Banksia Spinulosa

(1) This study investigated pollen and nutrient limitation of fruit-set in Banksia spinulosa var. neoanglica (Proteaceae) in natural sclerophyll forest during four flowering seasons from 1986 to 1989. (2) Fruit production differed fourfold among years indicating that the conditions determining fruit-set were variable. (3) Levels of cross-pollination, as estimated by visits of nectarivorous birds to inflorescences, differed threefold during the study. (4) In 1986, when natural levels of fruit-set were high, the number of fruits plant-1 was not increased by adding nutrients or cross-pollen, either separately or together. In 1988, when natural levels of fruit-set were lower than in 1986, fruit production plant-1 increased by 65% and 114% following the separate additions of nutrients and cross-pollen, respectively, and by 298% following the addition of both. (5) In 1989, plants that received additional nutrients in 1988 produced more fruits than did plants that did not receive nutrients. There was no such effect in 1987 following the 1986 experiment. (6) The extent of pollen and nutrient limitation of fruit-set may differ among years. Extra flowers may provide opportunities for plants to increase fruit-set when cross-pollination and nutrient levels are high.

Floral Biology and Inefficient Pollen Removal in Banksia spinulosa var neoanglica (Proteaceae)

Stigma receptivity, pollen longevity and rates of flower opening were examined in Banksia spinulosa var. neoanglica. The interaction between these aspects of floral biology and removal of self pollen by floral visitors, autogamous pollen deposition and autogamous fruit set was determined. Flowers were strongly protandrous; most stigmatic grooves opened and maximum stigma receptivity occurred 3-4 days after the flowers opened. Over 80% of pollen was viable when flowers first opened. Pollen longevity was extended; 58% and 33% of pollen was still viable 8 and 12 days respectively after the flowers opened. Rates of flower opening were slow with only 19-32 flowers opening per day, depending on temperature. More than 80% of flowers had self pollen remaining on their pollen presenters 5 days after the flowers opened. Autogamous pollination did not occur until at least 6 days after the flowers opened. Pollen deposition and fruit production were significantly less on autogamous than open-pollinated inflorescences. Pronounced protandry, extended pollen longevity and slow rates of flower opening in B. spinulosa may have been selectively favoured by inefficient removal of self pollen by floral visitors.

Predation by Insects Limits Seed Production in Banksia spinulosa var neoanglica (Proteaceae)

Application of insecticide to inflorescences of Banksia spinulosa var. neoanglica indicated that damage by flower and seed predators halved the number of seeds produced per plant. Both the proportion of inflorescences that produced fruits and the number of seeds produced per infructescence increased by 45% when insects were excluded. Infructescences in the insecticide treatment produced 28% more follicles than in the control group. Insects damaged the seed in 13% of follicles in the control group whereas there was no damage in the insecticide treatment. The proportion of follicles with aborted seed did not differ between the two groups. The greater seed set occurring when insects were excluded did not affect the weight of individual seeds or reproductive output in the next flowering season. Some inflorescences did not produce fruit even when insects were excluded suggesting that factors besides predation also limit fecundity of B. spinulosa.

Contribution Toward a Monograph of Ramaria. VII. New Taxa and Miscellany

New taxa proposed are Ramaria cystidiophora var. anisata, R. distinctissima var. americana, R. foetida, R. highlandensis, R. hilaris var. olympiana, R. schildii, and R. spinulosa var. diminutiva. Species circumscriptions for R. claviramulata and R. verlotensis are furnished based on additional collections. Ramariafibulata is proposed as stat. nov., and R. subspinulosa is considered separate from R. spinulosa.

Pollination and Seed Set of Banksia spinulosa: Evidence for Autogamy

The breeding system of Banksia spinulosa var. neoanglica in the New England National Park was examined by excluding pollen vectors and hand pollinating inflorescences. Fruit set of xenogamous and open inflorescences was greater than geitonogamous and autogamous treatments, although not all differences were significant. No differences were found in the number of seeds per follicle or seed weight between treatments. A reduced number of follicles and smaller seeds occurred in the apical third of inflorescences in all treatments. This report of autogamous seed set contrasts with previous findings for this species and indicates intra-specific variation in the breeding system.

Do pollinators influence seed‐set in Banksia paludosa Sm. and Banksia spinulosa R. Br.?

AbstractThe consequences of observed variations in pollinator activity for plant reproduction depend on the breeding system of the plant and also on whether pollination is a resource in short supply. These factors are frequently assumed rather than tested. In bagging experiments with Banksia paludosa in heath and B. spinulosa var. spinulosa in woodland, the present study demonstrated that seed‐set does not occur by autogamy and that pollinators are indeed necessary. Experimental addition of outcrossed pollen to inflorescences failed to produce any increase in the mean number of seeds per inflorescence, measured for non‐barren inflorescences, for either species. However, in B. paludosa, the addition of pollen increased the numbers of inflorescences that set seed from 20% (controls) to 45% (pollen‐added treatment). This suggests either unusual patterns of pollen movement among and within plants or control of the pattern of seed‐set within a plant. Pollen additions failed to alter seed‐set in B. spinulosa. It is possible that a greater abundance of pollinators in the woodland ensures adequate pollination for these plants

A Quantitative Description of the Vegetative Phenology of Herbs in a Northern Hardwood Forest

The vegetative phenology of populations of nine common herbs in a northern hardwood forest was measured quantitatively, using a method developed for resolving important details of phenological patterns. The species may be divided into four different phenological types: vernal photosynthetics (Erythronium americanum and Claytonia caroliniana), summer greens (Uvularia sessilifolia and Clintonia borealis), late summer species (Dennstaedtia punctilobula and Aster acuminatus), and semievergreens (Oxalis montana and Dryopteris spinulosa var. intermedia contrasted with D. spinulosa var. americana). Interspecific differences among and within phenological types and intraspecific variations along an elevational gradient are described in terms of yearly timing of development and senescence, durations of stages, and population synchrony. Concurrent measurements of environmental factors suggest interpretations of adaptive significances of the phenological patterns.

Plagiochila killarniensis Pears. in the British Isles

Plagioehila killarniensis Pears. is reinstated as a species. It differs from P. spinulosa in many characters including its more patent leaves with a sharply defmed vitta, and the dentate antical margin of its female bracts. P. spinulosa var. inermis Carr. is shown to be a synonym of P. killarniensis, and P. punetata var. owenii (Steph.) Macv. of var. punctata. Both sexes of P. killarniensis occur in the British Isles, but male plants of P. spinulosa have not been detected, and those of P. punctata have been seen only once. P. killarniensis tolerates more exposure than P. spinulosa, but does not extend so far north.

The Distribution of Dryopteris spinulosa and Its Relatives in Eastern Canada

DONALD M. BRITTON*,1 There are some excellent distribution maps of vascular plants from Quebec and Labrador in Rousseau (1974). However, his map for Dryopteris spinulosa (0. F. Muell.) Watt actually groups data for all the species of Dryopteris which have been referred to as the D. spinulosa complex, much as Boivin (1966) did when considering D. austriaca (Jacq.) Woynar. This conceals the interesting geographic patterns found in eastern North America, where there are three northern limits in Quebec and Labrador and one southern limit. Biosystematists (Wagner, 1971; Wherry, 1961) recognize two diploid species and two tetraploid species in this complex. The diploids are D. intermedia (Muhl.) A. Gray and D. assimilis S. Walker (which also has been called diploid D. dilatata or diploid D. spinulosa var. americana). The tetraploids are D. spinulosa (0. F. Muell.) Watt (sometimes called D. carthusiana (Villar) H. P. Fuchs) and D. campyloptera Clarkson. After determining that the northern Clay Belt plants near Amos were in fact diploid and not tetraploid D. campyloptera as expected (Britton, 1967), I decided in the tradition of Wherry to attempt to delineate the ranges of the D. spinulosa complex species in Quebec, and more specifically to see if the ranges of the diploid D. assimilis and the tetraploid D. campyloptera overlapped. For studies of genomic analysis and chromatography, a concerted effort was made to find hybrids between these four species of the complex, which were found growing together at Metis and Mt. Albert in 1968. Dryopteris assimilis was looked for unsuccessfully in Prince Edward Island, Nova Scotia, and New Brunswick in 1970. In 1971 D. campyloptera was studied in Vermont and north in the Laurentians to St. Donat de Montcalm and Mt. Tremblant. In 1972 I collected material north of Quebec City and along the north shore of the St. Lawrence River to Sept Iles and from there to Labrador City. The cytological vouchers, which represent over 200 different plants, have supplied material for chemotaxonomic studies (Widen & Britton, 1971; Britton & Widen, 1974; Widen et al., 1975), and are a sample from which extrapolations can be made to similar phenotypes for the purpose of mapping. The maps in this paper have been prepared from selected

Virgin Hemlock Forest Segregates in the Joyce Kilmer Memorial Forest of Western North Carolina

1. Two segregates can be readily distinguished in the virgin hemlock forest which occupies the flats and lower slopes in the Joyce Kilmer Memorial, a part of the Nantahala National Forest in western North Carolina. The first of these types, restricted to the flats and lowermost parts of the slopes along the streams, is characterized by a dense undergrowth of Rhododendron and a sparse herb layer. The other type, occurring higher up on the slopes, has a very open shrub stratum but a fairly dense and diversified herb layer. 2. Tsuga canadensis is the dominant tree species in both types, with Fagus grandifolia, Tilia americana, Betula lenta, Fraxinus pennsylvanica, and Halesia carolina as almost constant associates. Liriodendron tulipifera and Acer saccharum are more abundant in the Herb type, while Betula lutea is restricted to the Rhododendron type. The total tree density is lower, but the BA is greater in the latter type (60% more). Hemlock reproduction is about equivalent at the seedling stage, but saplings are considerably less numerous in the Rhododendron type. Age-diameter relationships in hemlock indicate that the species is able to stand suppression relatively well but not so long as some other climax conifers. 3. Herbs which are constants for both types include Mitchella repens and Viola rotundifolia, observed in every stand, and Tiarella cordifolia, Laportea canadensis, Trillium sessile, Dryopteris spinulosa var. intermedia, and Oxalis montana, with lower presence values. In spite of their general distribution, these are the important herbs of the Rhododendron type. The characteristic herbs of the Herb type are therefore those numerous additional species which appear. Among these, Carex plantaginea, Medeola virginiana, Adiantum pedatum, and Polygonatum pubescens are exclusive and constant. 4. The soils are very similar under both types. They are sandy loams with an A-C profile, good incorporation of organic matter, and good structure. The better growth of dominant components in the Rhododendron type is attributed to better soil-water relations, owing to topography and possibly to microclimatic differences. 5. A comparison is made with the two types (Rhododendron and Polycodium) of virgin hemlock forest found in Ravenel's Woods. Differences in species composition and in growth of hemlock lead to the conclusion that there are at least four types of hemlock cove forest, which are believed to be relic association-segregates of Braun's Tertiary Mesophytic Climax. The considerably greater BA of hemlock in Ravenel's Woods and the differences in associated species are attributed to differences in general climate (higher precipitation and lower temperature). 6. The sampling method used in this study is discussed. It consists of a strip random sampling in which each strip is in turn systematically subsampled at a 50% intensity.

Some Interesting Fern Papers in "Rhodora"

During 1915, there were published in Rhodora four papers of especial interest to members of the American Fern Society. The papers were written by Prof. Fernald in connection with his study of the flora of New England and northeastern North America, and contain changes in the naming of some well known species. The first paper1 deals with the North American representatives of Dryopteris spinulosa var. dilatata. On the basis of the pale scales of the American form called var. dilatata, together with the glandless indusia, and other facts, the conclusion is drawn that the so-called dilatata of eastern North America should be considered as

Notes on the Ferns of the Champlain Valley

Three years ago, during the summer of 1911, I spent six weeks botanizing in the Champlain Valley of Vermont, collecting not only pteridophytes, but phanerogams as well. Although records of the more important species have already been published in Rhodora (XV. 158-163, 200-201 (1913); XVI. 38-41 (1914)), my friend, Mr. Harold G. Rugg, has suggested that notes on the fernworts collected might prove of interest to readers of the JOURNAL. In the following notes I have accordingly included records of all the species collected, rare or common. My first month, from July to midAugust, was spent at Essex Junction, a railroad junction near Burlington, of some local fame as the scene of frequent railway accidents, and the rest of the time at Swanton, a small town about four miles below the Canadian border. Both towns are situated on large sandy deltas formed in glacial and slightly post-glacial times by the Winooski and Mississquoi Rivers, and deposits of limestone or marble with their characteristic species occur in both localities. A number of ferns, common enough at both places as they are nearly everywhere in the East, may be dismissed with a mere listing of their names. These are Adiantum pedatum, Dryopteris cristata, D. marginalis, D. spinulosa, D. spinulosa var. intermedia, D. Thelypteris, Asplenium filix-femina, A. Trichomanes, Cystopteris fragilis, Onoclea sensibilis, 0. Struthiopteris, Polypodium vulgare (collected at 4000 ft. on Mt. Mansfield), Polystichum acrostichoides, Pteris aquilina, Woodsia ilvensis, Osmunda Claytoniana, and 0. regalis. Dryopteris Boottii, D. cristata var. Clintoniana, and the splendid D. Goldiana were found once or twice at both localities. On a rich wooded