摘要:

A grouping of transformations is proposed: 1) “Element transformations”, aimed at changing relations between elements within a single character vector; and 2) “vector transformations”, aimed at changing relations between different character vectors. Logarithmic element transformation seemed suitable for revealing variation in size characters.Principal coordinate analysis (PCO) was appropriate for determination of dimensionality and structural extremes (parentage). Due to polynomial distortions, however, variation in extreme populations was underestimated and variation in intermediate populations exaggerated.A “character index”, the mean of a specimen's ranged characters, is suggested to replace Anderson's hybrid index. Knowledge of parentage and parental maxima, but not of variation in pure parental populations, is required. The character index combined with modified Gay triangles was found suitable for revealing the structure of the material, which showed mainly one‐dimensional variation. The material analysed comprisedArgyranthemum broussonetü, A. frutescens, a hybrid swarm and experimental F1hybrids between these species; andA. sundingü, which was found to be a stabilized hybrid derivative, probably evolved by hybrid speciation with ex

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1987.tb02030.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

The morphology of 175 specimens ofOrnithogalumbelonging to 12 species were analyzed on the basis of 31 characters. The methods used were cluster analysis (agglomerative clustering using Ward's average), principal components analysis (using correlation coefficients) and oligothetic characterization of clusters and species. The splitting level at which seven clusters were separated is the best possible one according to the criteria as used. The separation of nine clusters yields more information on the distribution of the species. Both the clusters and the species are separated from each other in the attribute space performed by the first, second and third principal component. The species of theumbellatum‐angustifoliumcomplex, i.e.O. umbellatum, O. angustifoliwn, O. refractum, O. monticolum, O. baeticumandO. algeriense, are clearly separated. A. parallel evolution of the pollen‐sterile strains of the bulbilliferous speciesO. umbellatumandO. angustifoliumcould be traced. A dichotomous key for all the species involved is propo

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1987.tb02031.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Taxonomic account ofSolandra, a neotropical genus ranging from Mexico and West Indies to South America, with phytochemical, ethnobotanical and ornamental interest. Its systematic position and affinities are discussed in connection toTrianaea, the other genus of the tribe Solandreae. Ten species are recognized:S. boliviano, S. brachycalyx, S. brevicalyx, S. grandiflora, S. longiflora, S. maxima, S. nizandensis, S. paraensis, S. guerrerensisand 5.guttata.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1987.tb02032.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

The new genusAschistantheraand its only species,Aschistanthera cristanthera, are described. Characteristics additional to the diagnosis are emphasized and parts of flowers and fruits and its distribution are illustrated.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1987.tb02033.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

The generic delimitation ofDrimiaandUrgineais discussed with special reference to flower and seed morphology (LM&SEM). The data support the joining of the two into one genus,Drimia.The following taxa are represented in East Africa (Kenya, Tanzania, Uganda):Drimia altissima, D. brachystachyscomb, nov.,D. calcaratacomb, nov.,D. congesta, D. elata, D. indica, D. macrocarpasp. nov., andD. porphyranthacomb. nov.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1987.tb02034.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

A lectotype has been selected forAciachne pulvinata.The nameA. uniflorais rejected as nom. illeg. Two new species,A. acicularis and A. flagelliferaare described and a key is provided. Leaf anatomy is described and discussed, several diagnostic‐characters have been found. Distribution maps and altitudinal ranges are discusse

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1987.tb02035.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Alopecurus gerardi, Poa alpina, andCarex curvulaare spontaneous, perennial forage plants distributed in the high elevation (2300–3200 m) pasture lands of Piedmont and Valle d'Aosta (Italy).Sedum atratumis an annual succulent which grows at elevations up to 3200 m. The three monocotyledons have, in comparison with corresponding plants from the low‐land, peculiar organographic and anatomic structures such as curling leaf lamina, vascular bundle sheath layer with chloroplasts arranged in a centrifugal fashion, low stomatal density (stomata number/cm2: upper epidermis x̄= 0–11.9; lower epidermis x̄= 7.66–11.55), thick cuticles, as well as higher values of S (H2O; g/dm2; x̄= 0.6–0.32), Sm (H2O g/mg Chi.; x̄= 0.11–0.16), SLW (g f. wt/dm2; x̄= 0.86–1.36), but lower SLA values (cm2/g f. wt; x̄= 75.07–116.77). All these data are correlated to water stress. Even though the leaf lamina anatomy possesses some features typical of C4plants, the presence of starch grains in the mesophyll chloroplasts indicates that these plants are probably C3ones.In spite of high values of thylacoid grana/thylacoid intergrana ratios, typical of shade plants (mesophyll chloroplasts: x̄ up to 3.81; bundle sheath chloroplasts: x̄ up to 5.3), and Chi a/Chl b ratios (x̄ up to 4.23 inC. curvula), the apparent absence of peroxisomes seem to indicate a very efficient dark phase of photosynthesis.S. atratum, in comparison with the typical CAM succulents, which live in dryer and warmer habitats, has a higher values of stomatal density (upper epidermis, x̄= 2.59; lower epidermis, x̄= 3.15) and of SLA (x̄= 24.98), but lower S (x̄= 3.83), Sm (

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1987.tb02036.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

In a study of natural populations ofSenecio integrifoliusin southern Sweden (1979–1983) seeds were found to disperse from mid‐June to late July and most of them germinated in autumn. No soil seed bank was observed. On a heavily grazed site few seeds were produced but the percentage of estimated germination was high (c. 75%). In two moderately grazed habitats 8–10% of the estimated number of seeds produced in permanent plots germinated. In a lightly grazed habitat many seeds were produced but only a small percentage germinated (1.4%). In field experiments the average germination was 50–53% when newly harvested seeds were sown where the vegetation had been removed, and 20–33% when sown in undisturbed vegetation at a moderately grazed site. Germination was much lower in a lightly grazed habitat (3–12%). Survival of seedlings was much higher in heavily and moderately grazed habitats than in lightly grazed habitats. Mortality tended to be higher during the growing season (mid‐April to early November) than during the winter, and increased markedly during a drought period in the summer of 1982. The half‐life of plants established in 1980 varied from 39.3 years at the most intensively grazed site to 7.2 at the lightly grazed site. The number of flowering stems varied between years mainly according to weather. Few plants in the permanent plots flowered every year, the flowering being most frequent at heavily grazed sites. It is concluded that heavy grazing by cattle after seed dispersal is the appropriate management for maintainingS. integri

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1987.tb02037.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

An analysis employing parsimony and character compatibility methods is carried out for selected species in the various families constituting the order Boletales s.l. The results indicate that Paxillaceae is polyphyletic, actually representing a primitive matrix from which many of the other families have evolved. Gyrodontaceae is also polyphyletic, and its various genera should be included within other families. The analysis does not support that Xerocomaceae and Boletaceae should be regarded as two separate families. It indicates that the genusSuillusshould be included within Gomphidiaceae. On the other hand, it strongly contradicts any relationship betweenSuillusandChalciporuson one hand, andStrobilomyceson the other. The latter genus must be very isolated from the other genera analysed. The gastroid families Rhizopogonaceae and Chamonixiaceae seem to have derived from progenitors related to Boletaceae andGyroporus(here regarded within Paxillaceae) respectively. Coniophoraceae is probably derived from precursors related to the more primitive representatives in Paxillaceae.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1987.tb02038.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Seven species of the lichen genusHyperphysciaand three ofPhysconiain East Africa are treated. The morphology, chemistry, distribution, habitat and relations between the taxa are discussed. Of the genusHyperphysciatwo new species are described,H. isidiataandH. pruinosa, and two new combination made,H. granulataandH. tuckermanii.Of the genusPhysconianone of the species has previously been reported from the area.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1987.tb02039.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY