ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1990.tb00184.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

KADEREIT, J. W., 1990.Some suggestions on the geographical origin of the central, west and north European synanthropic species ofPapaverL.Papaver rhoeas, P. dubiumsubsp.dubiumand subsp.lecoqii, P. argemonesubsp.argemoneandP. hybridumare considered to be introduced in central, western and northern Europe. An analysis of the geographical distribution of the closest relatives of these five taxa leads to hypotheses on their geographical origin. It is suggested thatP. rhoeasoriginates from the eastern border of the Mediterranean, where it might have differentiated only under human influence. The origin of P.dubiumsubsp.lecoqiiis suggested to lie in S.E. Europe or west Anatolia, and that of subsp.dubiumin S.E. central Europe.Papaver argemonesubsp.argemonemight have differentiated from two related subspecies in west Anatolia. No suggestions can be made with respect toP. hybridum, which is taxonomically isolated. The assumptions necessary for hypotheses on the geographical origin of synanthropically widespread taxa are briefly discussed.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1990.tb00185.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

RICHARDS, A. J., 1990.Studies inGarcinia, dioecious tropical forest trees: agamospermy. InGarcinia, agamospermy is known or suspected for ten species. Most are facultative agamosperms, with males occurring, but males are probably lacking inG. mangostana. InG. mangostanaandG. hombroniana, adventitious embryony occurs autonomously, and haploid parthenogenesis may also occur rarely. InG. parvifolia, it is reported previously that gametophytic agamospermy occurs, and adventitious embryos are suppressed. Autonomous endospermy is found inG. mangostanaandG. parvifolia. InG. hombroniana, endosperm probably only develops after PEN fertilization. InG. hombroniana, some proembryos are formed precociously, and further proembryo formation is inhibited by sexual embryos. Asexual proembryos tend to occur in large ovules in small ovaries, and sexual embryos tend to occur in small ovules in large ovaries. It is considered that facultative agamospermy renders the genusGarciniaparticularly suitable for the development of new types of fruit. Agamospermy in a dioecious genus, adventitious embryony in the absence of fertilization and/or pseudogamy, and the co‐occurrence of gametophytic and sporophytic agamospermies in the same genus are unusual phenomena, which are discussed in the context of the lifestyle of a tropical forest tree. ForG. hombroniana, n= 24, and forG. cowa, n= 26 are reporte

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1990.tb00186.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

RICHARDS, A. J., 1990.Studies inGarcinia, dioecious tropical forest trees: the phenology, pollination biology and fertilization ofG. hombronianaPierre.Garcinia hombronianais a facultative agamosperm which is pollinated byTrigonabees. Nectar is restricted to the large discoid stigma (or pistillode in male flowers), which also captures and hydrates pollen. The ‘wet’ stigma and binucleate pollen suggest thatGarciniaarose from hermaphrodite plants with a gametophytic self‐incompatibility system.On stigmas, nectar is secreted early on three or four successive days. On male pistillodes, nectar is secreted when anthers dehisce, on the second morning after anthesis. Pollen is most viable when freshly collected, but some viability remains four days after collection. Pollen germinates within 24 h of hydration. Similar results to pollinations are obtained by germinating pollen in 1 % sucrose.Garcinia hombronianaflowers principally from January to June. Cultivated females are considered as ‘big bang’ strategists. Male flowers are considered as ‘steady state

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1990.tb00187.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

HEDRÉN, M, 1990.TheJusticia elegantulacomplex (Acanthaceae) in tropical Africa. TheJusticia elegantulacomplex (part ofJusticiasectionHarnieria, Acanthaceae) is revised and the following taxa recognized:Justicia elegantula, J. lithospermoidesandJ. metallorum. Multivariate analysis of 25 morphological characters revealed two variational trends withinJusticia elegantula, one correlated with season and another with geographic location. Descriptions, illustrations, distribution maps and a key are provided

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1990.tb00188.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

DAVIS, A. P.&JURY, S. L., 1990.A review ofIrisL. seriesUnguiculares(Diels) Lawrence (Iridaceae). The morphology, pollen, chromosomes and distribution of these plants are discussed and a new systematic account of the series is given.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1990.tb00189.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY