摘要:

DAVIES, K. L., 1991.A brief comparative survey of aerophore structure within the Filicopsida.A comparative account of the structure of petiolar aerophores and aerating systems within certain fern families is presented. Approximately 100 species were examined and the results suggest that the petiolar aerophore structure and its relationship to internal petiolar anatomy could prove a useful taxonomic character at the generic level.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1991.tb00220.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

VALERO, M.&HOSSAERT‐MCKEY, M., 1991.Discriminant alleles and discriminant analysis: efficient characters to separate closely related species: the example ofLathyrus latifoliusL. andLathyrus sylvestrisL. (Leguminosae).Two speciesof Lathyrus (L. latifoliusandL. sylvestris)were compared using allozymes and quantitative vegetative and reproductive traits. The variation in these characters was analysed in several populations of the two species located in south‐western, central and northern France. In a site where the two species are syrapatric, intermediate plants are described. The two species can be identified by discriminant alleles. The genetic structure observed for intermediate plants in the zone of sympatry indicates, paradoxically, the occurrence of a strong reproductive barrier between the two species. The discriminant analysis performed on the quantitative traits readily distinguishes the two species and confirms the reproductive isolation between them. The quantitative character that best discriminates between the species is the number of ovules per ovary, a variable which has non‐overlapping distributions in the two species. We discuss how this character, usually ignored, may be better for distinguishing species than some traditionally used reproductive traits such as the number of seeds per fruit. The vegetative traits studied (e.g. degree and intensity of branching) also differ significantly between the two species. Divergent evolution of these traits in the two species is discussed in relation to differences in the original habitats of the two sp

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1991.tb00221.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

THULIN, M., 1991.Another arborescent umbellifer: a new species ofSteganotaeniafrom north‐east tropica] Africa.The new speciesSteganotaenia commiphoroidesis described from central and southern Somalia, and south‐eastern Ethiopia. It differs from the likewise arborescentS. araliacea, widespread in tropical Africa, in, for example, its 3‐foliolate or occasionally simple leaves, leaf teeth with shorter aristae, shorter petioles and pedicels, and fruits with a pair of distinctly winged dorsal r

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1991.tb00222.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SHAFFER‐FEHRE, M., 1991.The endotegmen tuberculae: an account of little‐known structures from the seed coat of the Hydrocharitoideae (Hydrocharitaceae) and ofNajas(Najadaceae).The sub‐cellular protuberances from the inner tegmen layer have been given various names in earlier literature. Here named ‘endotegmen tuberculae’, they vary in shape, size and density of distribution in the endotegmen of different taxa. These characteristics make them useful for taxonomic research at both genus and species level. Their shape is a major consideration in transferringHydrocharis dubiato the genusLimnobium.A further structure, ‘exotegmen tuberculae’, has been observed for the first time. This paper gives a survey of these structures and illustrates their taxonomic importance and its

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1991.tb00223.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SHAFFER‐FEHRE, M., 1991.The position ofNajaswithin the Alismatidae (Monocotyledones) in the light of new evidence from seed coat structures in the Hydrocharitoideae (Hydrocharitaceae).This paper gives details of seed coat structure in several genera of the Hydrocharitoideae (Hydrocharitaceae) andof Najas(Najadaceae). The taxonomic positionof NajasL., as a genus or as the basis of a higher taxonomic category, has changed with the publication of every new system of classification in which it was considered. In the light of evidence derived from seed coat anatomy, particularly that of the testa, and from the presence of endotegmen tuberculae,Najasis placed in the enlarged tribe Stratioteae in the subfamily Hydrocharitoideae (Hydrocharitaceae

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1991.tb00224.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

CAMARA‐HERNANDEZ J.&GAMBINO, S., 1991.Early ontogenetic development of the pistillate inflorescence in a diploid perennial teosinte(Zea diploperennis, Poaceae).The early ontogeny of pistillate inflorescences of%ea diploperennisin plants grown at the latitude of Buenos Aires, Argentina, is investigated using the scanning electron microscope. The pattern of development of the inflorescence is similar to that in staminate and mixed inflorescences, starting with the formation of a pair of spikelets from a common branch primordium initiated in the axil of a bract on the ear axis. This bract arrests its development and aborts early. After initiation of an outer glume on both spikelet primordia, the pedicellate spikelet arrests its growth and aborts resulting in the mature inflorescence having two rows of solitary spikelets arranged distichally. This is significantly different from the pattern observed by other authors in plants grown in different environments (such as in natural populations in Mexico

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1991.tb00225.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY