摘要:

The following new species are described:Polygala gypsophila(northern, central and southern Somalia, on gypsum),P. bariensis(northern Somalia, on limestone),P. hamarensis(coastal dunes near Mogadishu),P. argentea(central Somalia, on limestone near coast),P. gawenensis(central Somalia, on limestone),P. effusa(central Somalia and eastern Ethiopia, on sand),P. citrina(southern Somalia, on granitic outcrops).P. meonanthais reported for the first time from Somalia.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb02089.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Acacia ochracea, a new species in theA. Senegalcomplex, is described and illustrated. It is a common and conspicuous tree over large areas in the western Bay Region and in the Gedo Region in SW Somalia.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb02090.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The genusTrachomais considered congeneric withTüberolabium.All necessary transfers toTüberolabiumare made. Four new combinations are made in the recently establishedParapteroceras.A key to the species ofParapterocerasand a key toParapterocerasand allied genera are provide

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb02091.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Revision of the genusLeptogonumresulted in the recognition of one species with one variety. A new combinationL. domingensevar.molleis proposed. The systematic position ofLeptogonumis discussed. It is considered to be phylogenetically old and isolated genus within Polygonaceae.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb02092.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Owerwintering strategy of the sub‐arctic evergreenDiapensia lapponicahas been studied by examining storage substances in the stem cells throughout different seasons. Stem segments were taken from 5 and 20 mm behind the shoot tip, fixed in glutaraldehyde/formaldehyde and embedded in Epon. Semithin sections were stained with Toluidine blue for general observation, Sudan black for lipids, Amido black for proteins and periodic acid‐Schiff s reagent (PAS) for carbohydrates. Lipids occurred abundantly throughout the year and seem to be the main storage substances. They were particularly common in mid‐winter in the lower part of the shoot. The highest lipid content was found in the pith cells and parenchyma cells of the conductive tissues. Large amyloplasts appeared in mid‐summer in higher amounts in the cortex than in the pith of the upper shoot, but vice versa in the lower stem. Starch was almost entirely lacking from November to April. Amido black staining did not indicate presence of protein bodies at any season.The occurrence of lipids and starch grains in the stem ofDiapensiais in general similar to the occurrence of these substances in the leaves throughout the annua

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb02093.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Geranium robertianumbears three types of glandular uniseriate trichomes which originate from a single protodermal cell and develop through periclinal divisions. Type I trichomes are procumbent and have an oval apical cell, two stalk cells and a basal cell. Type II trichomes are erect and have a pear shaped apical cell, two stalk cells and a basal cell. Type III trichomes are much longer than the other two types and have an elongated apical cell, five long stalk cells and a basal cell. Type I and type II trichomes are common on leaves while III trichomes are more abundant on flower structures.Type I and type II trichomes secrete terpenoids and phenols. Type III trichomes are characterized by the accumulation of anthocyanins in the apical cell and secrete flavonoids.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb02094.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The aims of this paper are to detect floristic variation within different types of tall‐fern dominated vegetation and to interpret these patterns in terms of environmental variables. Numerical approaches have been applied to a large and varied vegetational data‐set with associated environmental data from stands dominated byAthyrium distentifolium, Thelypteris limbosperma, andMatteuccia struthiopterisin different parts of western Norway. The numerical procedures of two‐way indicator species analysis, simple discriminant functions, and canonical correspondence analysis have been used, and the strengths and weaknesses of these as tools in discerning vegetational‐environmental relationships are discussed. For each of the 96 quadrats investigated, 17 environmental variables were measured. The investigation shows that some of the observed differences in vegetational composition can be explained in terms of relatively simple soil and climatic variables measured for each quadrat. The ferns appear to be ecologically well separated.T. limbosperma‐dominaledstands are mainly characterised by low soil fertility, high January temperature, and high humidity.A. distentifolium‐dominatedstands are associated with low winter temperatures, andM. struthiopteris‐dominatedstands have high soil fertility and high summer

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb02095.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Part of the “Cortinarius, Flora Photographica, vol. I” in which six new combinations and thirty infrageneric names published for taxa in the genusCortinariusare validated, including 7 sections and 21 subsections in the subgenusPhlegmac

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb02096.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Two different ascocarp ontogenies have been demonstrated inSphaerophorus(Caliciales). A globose primordium arises in both species investigated. InS. globosus, the primordium wall encloses the whole structure during the hymenium development, although a weak differentiation of the basal part takes place, while inS. tenerthe wall is clearly differentiated into a watchglass‐like basal part and a cap‐like apical part not in contact with the basal part. InS. globosus, the cover disintegrates during the mazaedial development. InS. tener, the cover persists until the mazaedium is well developed, and is then shed, most often in one piece, thereby exposing the spores. The mechanism of the shedding and the possible biological consequences of the specialized ascocarp ontogeny inS. teneris discussed. The spore ontogeny ofS. tenerhas also been investigated. No ornamentation is deposited on the spore surface until the spores are liberated from the asci. The spore ontogeny thus resembles that ofS. murrayii, but only a small amount of mazaedial material is deposited on the spore surface. The classification of the species is discussed and it is concluded that the genusSphaerophorusas presently circumscribed is very heterogene

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb02097.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Compsonema minutum, the type species of the genus, shows two features which are characteristic for the Scytosiphonales: the presence of a single large lobed chloroplast per cell with a large pyrenoid in a pyrenoid sac, and a partly parenchymatous prostrate system morphologically similar to the knot filaments in the comparable thallus parts of, for example,ScytosiphonandPetalonia.The genus, therefore, finds a natural position in the Scytosiphonales.The direct type of life history seems to dominate in the reproductive pattern as swarmers from the plurilocular sporangia develop without copulation into plants similar to the parental plant. One unilocular sporangium has been observed but the fate of the swarmers from this reproductive structure has not been determined. The fine structural background for the formation of overlapping wall elements has been investigated. Lacunae develop between the layers in the 2‐layered wall and the outermost part of the wall gradually becomes electron dense. During growth the electron dense part breaks away to become separated from the rest of the wall in the area with lacunae.The plasmodesmata in the transverse walls show a single membrane profile similar to for exampleFucus, i.e. the pores provide continuity but lack desmotubules and E

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1990.tb02098.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY