摘要:

SUMMARYThe history of the genusSpartinain Britain is traced from herbarium records and publications. This historical information and a morphological study of living plants strengthen the view that sterile S. xtownsendiiarose inc.1870 in Southampton Water as a hybrid between native S.maritimuand introduced American S.alterngora.The fertile Amphidiploid arose in 1890 and spread at the expense of the species populations. It is shown that species and hybrids of the S. xtownsendiicomplex can be separated by a combination of only a few well‐defined morphological characters, and by stomata and pollen grain details.A polyhaploid seedling of low vigour among Amphidiploid progeny is described and its existence and resemblance to S. xtownsendiiF1emphasizea the relationship between thisPIhybrid and the Amphidiploid. Putative backcross hybrids of S. xtownsendiiAmphidi‐ ploid with X.alternijforain Southampton Water provide conclusive evidence of

ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1967.tb00076.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARYEight tree species of freshwater swamps are listed, together with a brief description of their adaptations repeatedly occurring in waterlogged soils. Two widely spread West African trees(Anthocleista nobilis, Xylopia staudtii)are described as species with well differentiated pneumatophores. New details on morphogenesis of knee‐roots inMitragyna ciliataandSymphonia globuliferaare recorded. Ecological significance of horizontal surface‐roots inAlstonia booneiis mentioned. The structural differences between the aerotropic roots inBaphia hookeriandPhoenix reclinataare explained. A brief discussion dealing with possible functions of the root adaptations in waterlogged soil is attac

ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1967.tb00077.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARYPrevious taxonomic vicissitudes of the family are examined and the form and variation of the vegetative organs described. Detailed accounts are given of the comparative anatomy of all the plant members (except the flower) ofButomus umbellatus, Hydrocleys nymphoidesandLimnocharis flava.Special facets of structure are discussed in an attempt to correlate its organization with the influence of environment and to interpret its taxonomic significance.

ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1967.tb00078.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARYThe characters that distinguish the two species ofEricasect.CallicodonBenth. are discussed and it is shown that they can be distinguished by the degree to which the anthers are exserted, by the habit, and by the degree of development of infrafoliar ridges on the young twigs, and that they have separate areas of distribution, one in southern continental Europe, the other in the Iberian peninsula, western France and western Ireland. The nomenclature of the two species is also considered and it is shown that the correct name for the former species isErica herbaceaL., notE. carneaL., and the correct name for the latter species isE. hibernica(Hook.&Am.) Syme, notE. mediterraneaL. It is also shown that the nameE. viridi‐purpureaL. cannot be applied to a South African heather and that the correct name for the species currently so called isE. mauritanica

ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1967.tb00079.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARYThe vegetative, floral and fruit morphology and anatomy ofChlaenosciadium gardneri,a monotypic, hydrocotyloid genus of Umbelliferae from Australia, is described in some detail. On the basis of comparisons of these observations with available reports for other genera of the tribe, as well as examination of herbarium material of these genera, it is apparent thatChlaenosciadiumis a distinct taxon which exhibits affinities withCentellaof Drude's Hydrocotylinae andXanthosia, PentapeltisandSchloenolaenaof his Xanthosiinae. The characters which lead to such a conclusion include: the leaf morphology and over‐all aspect, the paracytic stomata; the nature of the trichomes; the branching pattern of the inflorescence; the type of bracts and bractlets of the inflorescence; the type of petals; the anatomy of the fruit; and in particular, the presence of transverse vascular bundles in the flower and fruit. The absence of sepals is the only feature which readily excludesCMae. no‐sciandium,and evenCentella,from the Xanothosiinae. In the light of this investigation there is a need for a re‐evaluation of relationships within the subtribes of the Hydrocotyleae as defined by

ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1967.tb00080.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

摘要:

SUMMARYThe paper is concerned with two species of the Chytridiales belonging to the genusZygorhizidiumwhich parasitize diatoms in the plankton of lakes.Z. melosirae,a parasite ofMelosira,was first described by the writer in 1950. Later, in 1953, another chytrid belonging to this genus was found onSynedraandAsterionella.Although it showed a close resemblance toZ. melosiraeit was nevertheless thought to be different and diagnosed as a separate species namelyZ. planktonicum.However Paterson in 1958, after studying parasites belonging to the genusZygorhizidiumin several Michigan lakes, U.S.A., put forward the view thatZ. melosiraeandZ. planktonicumwere synonymous. More recent findings made by the writer on the other hand have strengthened the original view that in fact two distinct species exist.Collections ofZ. planktonicumfrom two new localities have been obtained and observations made on living material which are here described.Z. melosiraehas also been re‐investigated and additional data concerning its morphology are described. A Latin diagnosis ofZ. planktonicumis provided in order to validate this species, and the diagnosis ofZ. melosiraeis emended. Evidence so far suggests that there are distinct host‐parasite relationships separating the two species and some examples are described. In conclusion the writer retainsZ. melosiraeandZ. planktonicumas separate spec

ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1967.tb00081.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY

ISSN:0368-2927    

DOI:10.1111/j.1095-8339.1967.tb00076a.x

出版商:Blackwell Publishing Ltd    

年代:1967

数据来源: WILEY