摘要:

The South African genusHymenolepisCass. was recently distinguished fromAthanasiaL. by Källersjö. It differs by its slender capitula and a pappus of scales. A key to the 7 species is presented and the new speciesH. cynopusBremer&Källersjö is descri

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1985.tb01688.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Most blackberry species are apomictic but pseudogamous, i.e. embryo development is dependent on prior pollination. Two different types of stamen arrangement were noted in senescing flowers of 18 Swedish species and 2 common cultivars. The stamens of ‘cross‐pollinating’ species seldom touch the stigmas while those of ‘self‐pollinating’ species instead arch over the pistils and dry up in this position. All species set seed well after artificial self‐pollination and are thus self‐compatible. Isolation experiments were carried out during 3 years. When inflorescences were bagged, seed set was drastically lowered in ‘cross‐pollinators’ but remained almost unaltered in ‘self‐pollinators’. The different responses to isolation are probably due to th

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1985.tb01689.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Within South African Asteraceae‐Anthemideae there is a group of genera containing furanosesquiterpenes rather than the common polyacetylenes. Of these genera,Asaemia(Harv.) Ham. ex Benth.&Hook.,AthanasiaL.,EumorphiaDC.,Gymno‐pcnfziaBenth.,PhymaspermumLess. andSfilpnophyfonLess. have been investigated morphologically especially with respect to fruit structure. As a result of the investigationsStilpnophytonhas been reduced to synonomy underAthanasiaL. emend. Källersjö (with 36 spp.) and five species ofAthanasia, together withPhaeocephalusS. Moore., are placed in the revived genusHymenolepisCass. (with 7 spp.).BrachymerkDC. and four misplaced species ofAihanasiaare included inPhymaspermumLess. emend. Källersjö (with 17 spp.). Nine other misplaced species ofAthanasiaand onePentziaThunb. species have been described as a new genusInulaniheraKällersjö (with 10 spp.), a group without furanosesquiterpenes. The two monotypic generaAsaemiaandGymnopentzia, andEumorphia(with 6 spp.) remain unchanged. The interrelationships of the genera possessing furanosesquiterpenes are shown in a cladogram. There are 25 new combinations inAfhanasia, Znulanthera, HymenolepisandPhy

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1985.tb01690.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

In connection with a revision ofGerberaL. nom. cons. in Africa the genusPerdiciumL. is revised. The genus includes two species,P. capenseL. andP. leiocarpumDC. in the Western Cape Region of South Africa.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1985.tb01691.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

The species ofUreraGaud. occurring in eastern tropical Africa are revised. Three species are recognized:U. cameroonensisWedd., occurring from Uganda to the South African Republic (Natal),U. sansibaricaEngl., restricted to the coastal zone of Kenya and Tanzania, andU. hypselodendron(Hochst. ex A. Rich.) Wedd., occurring in montane forest from Ethiopia to Malawi. The original material ofU. hypselodendronvar.flamignianaHauman (nom. inval.) and var.platyrrhachisHauman (nom. inval.) is excluded fromU. hypselodendron;the same applies to the other material ofU. hypselodendroncited from central Zaire in Flore du Congo belge. Distribution maps of the eastern African species are provided. Also included is a preliminary study and discussion of the generic subdivision ofUrera, with special reference to the species of this revision.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1985.tb01692.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

The preformed root primordia in stems ofSalk viminalisL. consist of undifferentiated cells. Forty‐eight hours after activation of the primordia in cuttings a root cap meristem was initiated four to five cell tiers from the surface of the primordia. The cells distal to the meristem divided only in an anticlinal plane, while in the meristem they divided mostly periclinally but sometimes anticlinally. After 72 hours a columella was established and the amyloplasts began to sediment in response to gravity. Shortly after this stage the roots began to bend slightly downward, probably as a geo‐tropic response. Six days after activation the root cap consisted of up to 15 tiers of cells. The ultrastucture of the cap cells just prior to emergence was studied in more detail. The plastids in the cells adjoining the root proper were typical proplastids. Distal to this cell tier starch accumulated in the plastids. In the fifth tier the amyloplasts were fully sedimented to the lowermost cell walls. The amount of ER increased with the distance from the initial cells and most of it was located at the distal periclinal cell wall. The nucleus and the vacuoles in the geo‐sensitive cells occurred in the space above the sedimented amyloplasts. The cytoplasm was less electron opaque than in the initial cells and the mitochondria had more cristae. In the distal cells of the columella and the lateral root cap secretion of mucilage seemed to have started. Numerous large dictyosomes were associated with large vesicles containing a fibrillar or granular material. The plasmalemma lining the distal periclinal cell wall had separated from the wall. A fibrillar material was present between the plasmalemma and the wall and also in intercellular spaces outside the roo

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1985.tb01693.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

The ontogeny of elastoviscin in the Orchidaceae was investigated with the light, transmission electron and scanning electron microscope. This substance is composed of unsaturated lipids and most probably a product of the ground cytoplasm of the tapetal cells. Different forms of elastoviscin are described. Further investigations are needed to determine whether it is homologous to pollenkitt.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1985.tb01694.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

This study deals with the vegetational changes and the course of erosion on two types of river banks bordering a river reservoir, in northern Sweden. The water‐level has been short‐term regulated since 1961, with an amplitude of about 3 m in the uppermost reaches of the reservoir and about 1 m furthest downstream. The pattern of regulation includes both a weekly and a daily rhythm. The banks of the river reservoir have been cut in fine‐grained sediments. The two sites selected for study were (1) a formerly littoral area (2) a formerly dry‐land area. Percentage cover and number of shoots were determined annually within belt transects subdivided into 10 times 10 cm quadrats, during the period 1977–1981.The course of bank erosion was initiated and mainly continued by water movements. In the formerly littoral area, erosion proceeded only slowly, whereas in the formerly dry‐land area erosion was rapid and the bank was continuously being undercut, leading to the formation of an overhanging mat of vegetation. As erosion progressed, this overhanging mat split up and slumped down into the reservoir. The vegetational changes on the overhang were considerable, while the terrace maintained a more stable vegetation cover. In the long‐term, the composition of the vegetation on the former littoral river‐bank remained more stable than on that cut into the former dry‐land area. The break‐up of the vegetation cover on the overhang also initiated secondary vegetational successions on the exposed soil. Considerable differences in the vegetation cover were also recorded from one year to the next. These differences were considered to be mainly due to differences in the rate and local course of erosion. Annual differences in the rhythm and/or amplitude of the fluctuations in water‐level were considered to be less impo

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1985.tb01695.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Samples from sixty‐two geolittoral sites along two rivers in northern Sweden were analysed in order to quantify possible differences in the vascular plant flora related to differences in the type of natural disturbance of the habitat (more disturbed: rapids (water flow) and lakes (wave action); less disturbed: slow‐flowing stretches). We found that the mean species richness was lower along the slow‐flowing stretches, than along the rapids and lakes, which were quite similar. When the geolittoral was subdivided into the three vertical belts, the floras of both the upper and middle belts exhibited this same pattern, whereas the species richness of the lower geolittoral belt was also low along the stretches of rapids. Along both rivers, the steepest gradient in mean species richness was recorded on the shores bordering rapids. The highest numbers of ‘constant’ species (frequency (F)>60%); and of those which showed a statistically significant (probability (p)>0.05) preference for a certain type of stretch in at least one of the three geolittoral belts, or in the entire geolittoral, were found along the rapids, in comparison to the flora of the slow‐flowing stretches. The flora of the lake shores also comprised a large number of specific species compared to that along the slow‐flowing stretches. The predominant species along the above‐mentioned stretches reflect both phytogeographical and habi

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1985.tb01696.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

The correct citation ofDermocybeas a subgenus ofCortinariusshould be:Cortinarius(Fr.) Fr. subgen.Dermocybe(Fr.) Sam., since it was Saccardo who definitely treatedDermocybeat the subgeneric level under the genusCoriinarius. According to the rules of nomenclature, the type species ofDermocybemust beCoriinarius cinnamomeus(L.: Fr.) Fr.Cortinarius croceus(Schaeff.: Fr.) H˜jiland is invalidly combined, and the new combinationCortinarius croceus(Schaeff.) Heiland is proposed. A neotype forCortinarius croceusis also proposed.Hydrocybe palustrisMoser is invalidly published since the author simultaneously published an alternative name,Cortinarius palusirisMoser. Therefore the combinationsDermocybe palustris(Moser) Moser andCoriinarius palusiris(Moser) Nez‐dojminogo are invalid. The earliest legitimate name of the taxon isCortinarius huronensisAmmirati&Smith.Cortinarius sphagnetiOrton is a later homonym ofCortinarius shagnetiSing. The earliest legitimate name of the former taxon isCortinarius tubariusAmmirati&Smi

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1985.tb01697.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY