摘要:

AbstractUntreated and chloroform-washed leaf surfaces of forty-three species of mosses have been examined with the scanning electron microscope. Of these, twelve species showed well developed superficial wax comparable with the epicuticular wax of flowering plants. A further eight had at least traces of surface wax of similar character. All the species which display a glaucous bloom to the naked eye have strongly developed surface wax, and all the species with demonstrable wax are endohydric in their adaptation to water use and movement.

ISSN:0373-6687    

DOI:10.1179/jbr.1979.10.4.531

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

摘要:

AbstractTetraphis geniculata, of North American origin, grown in a north-facing glasshouse in Britain, showed marked seasonality in the duration of protonemal growth before the appearance of thalloid protonemal appendages and shoot buds, in the number of thalloid appendages formed, in the variation in the number of leaves borne on shoots and in the production of gemma-cups. The plastochron scale was used as a measure of earliness in the production of gemma-cups. Shoots formed early in the year, following a prolonged protonemal phase, had a low average leaf number but later in the year, when the protonemal phase was reduced, the average leaf-number was increased. In this period of the year leaf-number varied with temperature; the higher the temperature, the higher the average leaf-number. When the average maximum monthly temperature in midsummer was in the range 23°–28.5°C there was complete suppression of the development of gemma-cups and therefore a prolonged period of vegetative growth.

ISSN:0373-6687    

DOI:10.1179/jbr.1979.10.4.539

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

摘要:

AbstractInPhascum cuspidatumthe number of sporophytes per inflorescence was found to increase, up to a certain limit, with increase in the number of archegonia present. The number of archegonia present varies with the age of the inflorescence, and fertilization terminates the production of archegonia. The common occurrence of solitary sporophytes is due to fertilization at a time when only a small number of archegonia is present in most inflorescences. Delayed fertilization, leading to an increase in the average number of archegonia per inflorescence, is a necessary precondition for increased occurrence of polysety. As many as five sporophytes in a single inflorescence formed capsules with spores without significant reduction in the size of capsules. Variation in the frequency of abortive embryos gave evidence of competition amongst sporophytes and this was most severe in the smaller inflorescences. The occurrence of polysety inTortula muralisappears to be governed by the same rules.

ISSN:0373-6687    

DOI:10.1179/jbr.1979.10.4.553

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

ISSN:0373-6687    

DOI:10.1179/jbr.1979.10.4.561

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

ISSN:0373-6687    

DOI:10.1179/jbr.1979.10.4.575

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

ISSN:0373-6687    

DOI:10.1179/jbr.1979.10.4.576

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

ISSN:0373-6687    

DOI:10.1179/jbr.1979.10.4.579

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

ISSN:0373-6687    

DOI:10.1179/jbr.1979.10.4.583

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

ISSN:0373-6687    

DOI:10.1179/jbr.1979.10.4.599

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor

ISSN:0373-6687    

DOI:10.1179/jbr.1979.10.4.ii

出版商:Taylor&Francis    

年代:1979

数据来源: Taylor