摘要:

AbstractDetached leaves ofPleurochaete squarrosain culture give rise to filaments and buds. In a nutrient-free medium and in the wild these filaments have features comparable to the rhizoids, while in the presence of nutrients they resemble chloronemata and caulonemata. The protonemal apparatus inPleurochaete squarrosaoriginates exclusively from the cells between the lamina and the midrib, while the buds grow both directly from these cells or from the protonemata. The formation of filaments and buds from leaves still attached to the stem is slower and less frequent, probably as a consequence of morphogenetic control by the apex. Asexual propagation inPleurochaete squarrosais discussed in relation to the experimental data and field observations. Regeneration from detached leaves is the major form of regeneration in this moss.

ISSN:0373-6687    

DOI:10.1179/jbr.1996.19.2.219

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractIn situ measurements were performed on the travertine-encrusted mossesCratoneuron commutatumvar.commutatumandEucladium verticillatumto obtain estimates of calcium carbonate deposition through photosynthesis, evaporation and carbon dioxide evasion. It was estimated that for both species, between 6 and 12% of the carbonate was deposited through photosynthesis, 10–20% through evaporation and the remaining 70–80% through gas evasion.

ISSN:0373-6687    

DOI:10.1179/jbr.1996.19.2.229

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractThe light climate within wet and dry samples of ten mosses from the maritime Antarctic was determined using a computer-controlled optical microprobe system. Irradiances decreased with increasing depth within the moss. The rate of attenuation varied greatly between replicates reflecting the heterogeneity of the moss macro-structure. Attenuation maxima were observed at wavelengths corresponding to the peaks of chlorophyll absorption around 675 nm and below 450 nm, although the inter-wavelength differences were small compared to the inter-replicate variation. Wide inter-specific variations in light penetration were observed. These were dependent upon a number of factors, of which the most important appeared to be stem orientation, with stem density, leaf size and orientation and pigment content possibly also affecting light absorption. In most mosses the inter-wavelength variation was lost and the depth of light penetration was increased on drying. The degree to which light penetration changed on dehydration was dependent upon the relative effects of structural and pigment changes. It is suggested that, as drying occurs, the increased penetration of light into the moss increases the photosynthetic potential of deeper layers, and hence reduces the loss of productivity by the moss.

ISSN:0373-6687    

DOI:10.1179/jbr.1996.19.2.235

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractBryophyte species fertility and life strategy composition on different substrates were examined along an altitudinal gradient incorporating lauriphyll forest,Erica-Myricawoodland andPinus canariensisforest at EI Canal y Los Tiles (La Palma, Canary Islands). One hundred and forty quadrats (each 625 cm2) were sampled along this gradient and 86 bryophyte species were recorded. The relationship of life strategy to environmental factors was explained using canonical correspondence analysis. The perennial life strategy is best represented in the more humid forests, but at higher elevations the colonist category is the most abundant. Colonists, short-lived shuttle and long-lived shuttle categories mainly occur on rocks in the driest forest. In the more humid forest, long-lived shuttle and short-lived shuttle categories are prominent on trees and the colonist category on soil. The perennial category is prominent on shady soils in the driest forest. In the more humid areas its abundance is similar on all substrates. Humidity conditions, substrate dynamics and vegetation disturbance seem to be the main factors influencing life strategy composition in the area studied. The lowest percentage of fertile species was found in the perennial life strategy category. The others have similar fertility (approximately 70%). The types of breeding systems, climatic conditions and rarity seem to have a great influence in the fertility of the species.

ISSN:0373-6687    

DOI:10.1179/jbr.1996.19.2.243

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractFissidens blechnoidesis a new name for a moss which previously has been widely referred to in error as,Fissidens anisophyliusDix.Fissidens anisophyllus, which closely resemblesF. leptocladusC. Muell.exRodway, is known with certainty only from the type and several other gatherings in the vicinity of the type locality.Fissidens blechnoidesis a distinctive species, relatively common and widespread. Both species are apparently endemic to New Zealand.

ISSN:0373-6687    

DOI:10.1179/jbr.1996.19.2.257

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractAn amended description ofDitrichum immersum, incorporating details of peristome and spore morphology, is given. Vegetative morphology, peristome features and spore morphology are compared toD. strictum, to which it appears closely related. The unusual occurrence of polysety is reported in a specimen ofD. immersumfrom Heard Island.

ISSN:0373-6687    

DOI:10.1179/jbr.1996.19.2.267

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractA key, descriptions and illustrations of Australian members of Ephemeraceae are provided. A new species,Ephemerum furcatumI. G. Stone is described;Ephemerum grosseciliatumC. Müll. is reduced to synonymy withEphemerum cristatum(Hook. f.&Wils.) C. Müll.; and two new Australian records,Ephemerum recurvifolium(Dicks.) Boul. andNanomitriopsis longifoliaCard. are reported.

ISSN:0373-6687    

DOI:10.1179/jbr.1996.19.2.279

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractThe taxonomically strongly isolated monotypic genusJubulopsis Schust. [type:J. novaezelandiae(Hodgs.&S. Am.) Schust.] forms a unique element in the Jungermanniales. It has been assigned toJubula Dumortand toNeohattoriaKamimura, and has been stated to be allied toFrullaniaDumort. - all genera of Jubulaceae (Porellineae). Discovery of the sporophytes conclusively shows the genus belongs to the Lepidolaenineae Schust. The coelocaule ofJubulopsis; the lack of a perianth and calyptra; the 4-lobed underleaves; the peculiar beaked capsule with a 3–4-layered wall; the free elaters; the massive haustorium—all preclude placing the genus in Jubulaceae. Although the numerous, minute, homogeneous oil-bodies and the coelocaule suggest a position in the Lepidolaenaceae,Jubulopsisis shown to differ from Lepidolaenaceae in lacking watersacs of all stem underleaves; in the non-incised water-sacs; the massive haustorium; the I-spiral elaters; and theFrullania-like thickenings of epidermal sporangium cells. The form of the lobule (‘water-sac’), however, is shown to be similar to that developed in most Jubulaceae and the stylus can be readily matched to that in some taxa ofFrullania. The genus is placed in a new family Jubulopsidaceae, endemic to New Zealand, whose synthetic features suggest a position near the base of the Lepidolaenineae. This suborder, and Porellineae, are assumed to share a common ancestor with the plesiomorphic features such as are retained in extant Ptilidiineae. The gametophytic features ofJubulopsissuggest that a multiordinal classification of the Jungermanniales is untenable.

ISSN:0373-6687    

DOI:10.1179/jbr.1996.19.2.297

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractThe relationships between the vegetative leaf dimensions, nerve width, proximal and median lamina cell dimensions, maximal alar cell width, and leaf curvature within the complex aroundDrepanocladus aduncus(Hedw.) Warnst. andD. polycarpus(Voit) Wamst. were evaluated in two sets of specimens: (1) material that was cultivated to evaluate variation within one clone, and (2) seventy-eight herbarium specimens, including most of the described variation within theD. aduncus-polycarpuscomplex. Within theD. aduncus-polycarpuscomplex most of the quantitative leaf characters studied show a statistically significant weak to strong correlation with each other. More strongly curved leaves are negatively correlated with the measurements of the other characters, otherwise the correlations are positive. The strongest significant correlation occurs between the median lamina cell length and the leaf length (r2= 0 97, single clone, r2= 0.92, herbarium material; based on median values for the character measures), but also for several other characters r2>0.50 were found. Median lamina cell length, which is often used to separateD. aduncusandD. polycarpus, and leaf length are thus two aspects of the same character. In the second specimen set, the variation of several other studied parameters, e.g. proximal lamina cell length and nerve width, are to a large part explained by the size variation of the plants. Taxa previously recognized within theD. aduncus-polycarpuscomplex cannot be circumscribed using characters studied in the present investigation, and it is suggested that new characters must be found if more than one species,D. aduncus, is to be recognized.

ISSN:0373-6687    

DOI:10.1179/jbr.1996.19.2.311

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractWe report the first European record ofPhyscomitrium maroccanumMeylan. It was collected from near Mazzarino (Caltanissetta Province), Sicily. The Sicilian plants are described and illustrated. Examination of the type material from Morocco suggests that, despite the rostellate operculum and mitrate calyptra, the species might be better treated as belonging toEntosthodon. Characters suggesting a placement inEntosthodoninclude the very elongate exothecial cells with incrassate walls and the papillose-reticulate spores. Information is given on environmental conditions and ecology of the species in Morocco and Sicily.

ISSN:0373-6687    

DOI:10.1179/jbr.1996.19.2.325

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor