摘要 :
A study of the seed morphology of Erica tetralix and the related species E. mackaiana and E. andevalensis was performed to evaluate the taxonomic importance of seed characters. Size and shape of seeds and surface cells were studie...
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A study of the seed morphology of Erica tetralix and the related species E. mackaiana and E. andevalensis was performed to evaluate the taxonomic importance of seed characters. Size and shape of seeds and surface cells were studied, and area, perimeter, main axis lengths, elongation and sinuosity were measured. Levels of intraspecific variation were considered by means of nested analysis of variance. The study of the intraspecific variation of the characters shows significant differences for lower levels, higher than variations between species for most characters. Levels of variation must be based upon the numerical analysis of seed characters for a correct approach to determining systematic value. E. mackaiana and E. andevalensis group together versus E. tetralix for sinuosity of testa cells. This is a good taxonomic character because it shows significant differences between species and no significant differences between populations. E. tetralix has strongly undulated testa cells while E. mackaiana and E. andevalensis have slightly undulated or curved testa cells. These two species can be discriminated by size of the seed, with seeds of 0.37-0.38 mm for E. andevalensis and 0.4-0.45 mm for E. mackaiana. Similarities are found in seed morphology for E. mackaiana and E. andevalensis, but we nevertheless consider the species status for the three taxa as the most natural taxonomic assignment. A key to the species is provided.
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摘要 :
A new subspecies of Erica lusitanica from the Cantabrian basin in northern Spain and south-west France is described. The diagnostic characters are found in seed type, corolla size, anther filament, exertion of stigma and presence ...
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A new subspecies of Erica lusitanica from the Cantabrian basin in northern Spain and south-west France is described. The diagnostic characters are found in seed type, corolla size, anther filament, exertion of stigma and presence of insect galls. The geographical distribution and ecological requirements are different as well. A complete description of the new subspecies is given. A comparison with the typic subspecies and the closely related species from section Arsace, E. arborea is dismissed..
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摘要 :
Seed morphology of Calluna vulgaris was studied. Seeds were collected and stored under cold and dry conditions. Scanning electron microscopy pictures were taken for whole seeds and details. Measures were made for different quantit...
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Seed morphology of Calluna vulgaris was studied. Seeds were collected and stored under cold and dry conditions. Scanning electron microscopy pictures were taken for whole seeds and details. Measures were made for different quantitative characters. A complete description is given. Seeds are tiny (0.55-0.65 mm), ellipsoid and with a reticulated pattern for testa sculpture, with the hilum region transformed into a pore. This character clearly distinguish Calluna seeds from those of Erica.
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摘要 :
Seed morphology of Erica australis, the only species of section Tylospora, was studied. SEM pictures were taken of whole seeds and details. Quantitative characters were analysed using one-way analysis of variance. Other secondary ...
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Seed morphology of Erica australis, the only species of section Tylospora, was studied. SEM pictures were taken of whole seeds and details. Quantitative characters were analysed using one-way analysis of variance. Other secondary characters such as weight of 100 seeds and colour were also recorded. Two main seed types were observed; the main discriminant characters were the caruncle length and the elongation of the seed body. This finding supports the existence of two subspecies, australis and aragonensis with a north-south gradient in morphological variation between the two subspecies, with intermediate populations in contact areas. The presence of a caruncle and the inconspicuous anticlinal walls of the surface cells are only found in this species within Erica genus in Europe.
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