摘要:

SUMMARYDuring 1971 the algae of a seepage area on the landward side of the dikes near Vlissingen (prov. Zeeland) were studied. The periodicity of the algae in three permanent sample plots was studied. Considerable seasonal differences in the cover and the composition of the algal mat could be noticed. A comparison is made of the algal flora and vegetation in two plant‐communities, theJuncetum gerardiiand thePuccinellietum fasciculatae. The algae appear to be of little use as characterizing species for communities based on higher plants. Combinations of certain species (especially of the genusVaucheria) are probably useful units for distinguishing algal communitie

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1974.tb00921.x

年代:1974

数据来源: WILEY

摘要:

SUMMARYGolgi vesicles and pollen tube walls isolated from germinatingPetuniapollen were chemically analysed. The protein: lipid ratio of the Golgi vesicles was 70:30. The total carbohydrate contents of the Golgi vesicles and pollen tube wall were found to be 7.2% and 61% of the dry weights respectively. The alkali insoluble material of the pollen tube wall contained 6% of the total carbohydrate; this material has been found to be cellulosic in nature. The sugar composition of the polysaccharides extracted from the Golgi vesicles and the tube wall is presented and discussed.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1974.tb00922.x

年代:1974

数据来源: WILEY

摘要:

SUMMARYThe wood descriptions ofJuniperus communisL. ssp.communisare compared with those of earlier authors. The average and maximum tracheid lengths and the ray height distribution frequencies offer a means of separating the wood of the erectJ. communisL. ssp.communisfrom that of the subspeciesnanaSyme with an entirely different habit.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1974.tb00923.x

年代:1974

数据来源: WILEY

摘要:

SUMMARYThe differentiation of the transmitting tissue of the style ofPetunia hybridawas investigated with the electron microscope. The cells of this tissue are surrounded by an intercellular substance. The same holds true for a number of styles of other investigated species. This intercellular substance may not be compared with a middle lamella. The earlier suggestion, that the transmitting tissue of solid styles is collenchymatic in nature, is rejected.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1974.tb00924.x

年代:1974

数据来源: WILEY

摘要:

SUMMARYTranslocation of a clone of the flat form of theLemna gibba – Lemna minorcomplex to the site of a gibbous population resulted in a persistence of the flat form, which is indicative of a genetical basis of the frond shape of this flat clon

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1974.tb00925.x

年代:1974

数据来源: WILEY

摘要:

SUMMARYThe chromosome numbers of 85 species of flowering plants from the Canary Islands were determined; 5 of the counts turned out to be new.Notes on some species are given. Numbers deviating from previous counts proved to occur inPolycarpaea divaricata(Pit.) Poir. andKoeleria phleoides(Vill.) Pers. 49 counts are new for the Canary Islands and are listed intable 2.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1974.tb00926.x

年代:1974

数据来源: WILEY

摘要:

SUMMARYWhen the sky is bright the shade light received at the north side of a deciduous hedge or strip of scrub contains much blue and far red radiation and little near red. The light intensity is relatively high but net radiation may be zero or slightly negative because of the strong long wave radiation loss to the „cold” bright sky. Dew persists in these situations and surface temperatures are often 6–8°C below ambient air temperature.Several Angiosperms, mosses, and liverworts seem to have a preference for this sit

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1974.tb00927.x

年代:1974

数据来源: WILEY

摘要:

SUMMARYA simple home‐made radiation thermometer and directional radiometer is described, which operates in the full range of the long‐wave spectrum. Sensitivity to short‐wave radiation is made small by using a white thermocouple as a radiation sensor and a glass shutter as a reference temperature.Some sources of error in radiation thermometry with the present and other instruments are disc

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1974.tb00928.x

年代:1974

数据来源: WILEY

摘要:

SUMMARYThe indigenous bread wheats from Northern Nigeria are described. They mainly belong to var.erythrospermumand var.meridionale. The Nigerian wheats are very susceptible to mildew. They belong to a group of Ne1m‐carriers, the Sudan zone perhaps forming an Ne1m‐region. These wheats may have come from the Near East, through Egypt. Later, a second wave of non‐carrier Sahara wheats may have broken the link between the Near East and the Sudan zone.Some varieties are morphologically different (var.graecum) and carry the Ne1w‐allele. They derive possibly from wheats introduced from India/P

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1974.tb00929.x

年代:1974

数据来源: WILEY

摘要:

SUMMARYHieracium incanum(Lam.&DC.) Zahn, which is treated as an autonomous species, is, together with its intermediate species and its hybrids, reviewed concerning nomenclature and geography. A few new subspecies are described.

ISSN:0044-5983    

DOI:10.1111/j.1438-8677.1974.tb00930.x

年代:1974

数据来源: WILEY