In order to define the present status of the genus Atrichum in Britain, data available from various floras and other publications are examined. Also literature relating to the cytology of the bryophytes is reviewed. Herbarium and living specimens are examined, the latter both in the field and under controlled conditions, to establish the range of variation in each species and to determine whether this is of genetic or environmental origin. Finnish and British material of A. tenellum are compared and two new races of A. undulatum, with distinct morphology, are described. Cytological investigation shows that A. crispum, A. angustatum and A. tenellum are all present as N=7 races in Britain. A. undulatum occurs mainly as the N=21 race with sporadic aneuploid specimens, but diploid (N=14) races, of very local distribution, also occur. The use of certain characters for species identification is discussed in the light of the results obtained in the investigation and the cytological basis of sex expression in the genus is discussed with particular reference to A. undulatum. Finally the species and races of Atrichum in Britain are described.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:703785 |
| Date | January 1957 |
| Creators | Wood, Marion M. |
| Publisher | Royal Holloway, University of London |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://repository.royalholloway.ac.uk/items/49dd0530-b0f3-4b78-a3fe-2b9817a980b9/1/ |
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