ALBERT

Description: It is commonly accepted that percentages of pollen in a pollen diagram do not express the exact composition of forests in earlier times. This inaccuracy is due to several factors, for instance the different quantities of pollen produced by plants, the distance of transport etc. A pollen diagram tells us only the change in pollen rain on the locality where we collected soil samples. In studying a pollen diagram we find a close relation between the variations in the percentages of a certain species and the area occupied by this species in the vegetation. When the percentage of pollen of a species increases, we conclude generally that the relative area occupied by this species in the vegetation increases too. However, such a connection might be doubted. The variety of factors controlling the dispersion of pollen is so great that the interpretation of a pollen diagram often meets with great difficulties. The connection between pollen rain and the composition of the vegetation is a simple one in the cases where we are dealing with a region of uniform vegetation. A diagram taken from a region in which the vegetation varies from place to place has to be regarded with some caution. Unfortunately such a heterogenity of the vegetation exists on the very place, where we want to compose a pollen diagram. The pollen rain which falls into a bog arises from two sources: a pollen rain from the local vegetation of the bog itself and one from the surrounding vegetation. When we are dealing with great bogs, the pollen produced by the vegetation of the bog itself will be mostly that of herbaceous plants, shrubs, and spores of the Bryophyta and the Pteridophyta. It is the rule rather than the exception that the bog will be treeless. The tree pollen in such a bog mostly takes its origin from the surrounding forests. It is a fortunate circumstance in a diagram that pollen of trees is separated from other pollen. However, one exception is seen in the way in which Iversen composes a diagram for late glacial times. This method, commonly used for late glacial times, embraces a pollen sum not only containing trees but also some herbaceous plants. The origin of the latter can, with some certainty, be accepted as from outside the bog. Therefore the local vegetation of the bog does not influence the percentages of tree pollen. The pollen sum thus comprises pollen of plants which grow under the same biotic conditions.

Description: In 1935 the present author reported the occurrence of this N. American species in the eastern part of Holland, province of Overijssel, in the vicinity of Almelo (JONKER, 1935). He found the species near the hamlet of Harbrinkhoek on a wet heath. The locality was also the only station of Wahlenbergia hederacea in the Netherlands, discovered a year before. Notwithstanding the extensive reclamations in that part of the country the species now still occurs in a number of localities around Almelo. The plants cannot be considered adventitious as they were found in places that are comparatively little influenced by human culture, judging from the occurrence, on the first-discovered locality, of e.g. Wahlenbergia hederacea. Gentiana pneumonanthe, Viola palustris, Radiola linoides, Linum catharticum, Scutellaria minor. The late Dr. Wachter discovered, in the herbarium of the Royal Botanical Society of the Netherlands, unidentified specimens of Hypericum canadense collected by Lako as early as 1909 in the same environment, perhaps even in the same station; and Dr. van Soest identified two specimens collected in 1918 by the late naturalist Bernink near Denekamp, about 20 km E of the above mentioned localities. Bouchard (1953, 1954, 1955) reported the discovery of the species in France, dept. Haute-Saône. The plants were found in large quantities, at the stony beach of oligotrophous lakes, together with Littorella uniflora. In his detailed publication of 1954 he discussed the possibilities of introduction. He concluded that the plants are not adventitious. They may be autochthonous or naturalized and then, when the latter is the fact, probably by U.S. army units that stayed in that area during world war I. He did not preclude, however, the possibility of a glacial relic. Bouchard overlooked the previous publication reporting the occurrence in Holland.

Description: A subdivision of pollen types based only on different dimensions is very dubious. An example is given, taken from the miocene browncoal in the Lower-Rhine area of Germany and the Netherlands.

Description: The Veluwe is a stretch of high ground in the central part of the Netherlands, north of the river Rhine and south of the IJssel Meer, i.e. the former Zuiderzee, and the polders reclaimed from the latter. Geologically the area consists of three formations: 1. ridges which owe their origin to the pressure of the land ise, and which consist of sands deposited as river sediments in preglacial times; 2. a fluvioglacial formation; on some of these plains small but steep hills are found; 3. aeolian sediments: löss and cover-sands (cf. VINK, 1949); they were deposited in the late-glacial period.

Description: Het adventiefterrein “de Dwinger” tussen Wartena en Eernewoude blijft nog steeds voor nieuwe verrassingen zorgen. In 1958 konden wij het terrein slechts een drietal malen bezoeken; toch werd er weer een aantal nieuwe soorten aangetroffen. Alleen de nieuwe soorten worden hier vermeld; vondsten van 1955, 1956 en 1957 vonden reeds eerder een plaatsje in het Corr.blad (no. 1,4,8).

Description: Mijn eerste aantekeningen over Solanum triflorum, die hier plaatselijk veelvuldig groeide, dateren van september 1952. Na 1955 was ik hier echter niet meer geweest en toen ik op 26 juli 1959 met A. Dijkshoorn opnieuw genoemde duinen onderzocht, was ik zeer benieuwd naar het voorkomen van deze soort. Op de ons vroeger bekende groeiplaats bleek Solanum triflorum geheel verdwenen te zijn en plaats gemaakt te hebben voor een ruige vegetatie van Calamagrostis epigeios en Hippophae rhamnoides. Op kleine afstand hier vandaan nu is kort geleden een stuk duin gedeeltelijk afgegraven en grote aantallen grote sterns, visdiefjes en meeuwen gebruiken deze zandvlakte als rustplaats. Het droge zand met veel schelpen is gedeeltelijk overdekt met een dun kleilaagje, He klei werd vroeger gebruikt om de dijken bij de monding van het Noordzeekanaal te verstevigen en is waarschijnlijk door verstuiven op deze plaats terecht gekomen, Deze zandvlakte van ongeveer 20 x 50 m bleek vrijwel uitsluitend begroeid te zijn met Solanum triflorum. Stuivend zand hoopte zich op tussen de Solanumpolletjes, die rijkelijk van vogelfaeces voorzien waren.

Description: Er bestaat op het ogenblik de neiging de kleine waterweegbree Baldellia ranunculoides (L.) Parl. te noemen in plaats van Echinodorus ranunculoides (L.) Engelm. In de nieuwste druk van de flora van Heukels-van Ooststroom werd deze naam in de Nederlandse literatuur geïntroduceerd. In mijn Alismataoeae-bewerking voor de Flora Malesiana (1957) heb ik de naam reeds afgewezen, doch een nadere argumentatie zal de Nederlandse floristen stellig interesseren. In 1854 heeft Parlatore Schinodorus ranunculoides als het type van een nieuw monotypisch genus Baldellia aangevoerd, doch hij werd niet nagevolgd. Volgens Pichon (1946) is er evenwel alle reden voor om dit wel te doen, want hij meende niet minder dan 4 kenmerken gevonden te hebben, waarin E. ranunculoides van de andere Echinodorus-soorten zou afwijken.

Description: Backer, C.A.: Butch-English taxonomic-botanical vocabulary. ed. 2. Bound. Dfl. 12,50; US$ 3. Steenis, C.G.G.J. van. Specific and infraspecific delimitation (repr. from Fl. Mal. vol. 5). Dfl. 7,50; US$ 2.

Description: Australia. Forestry and Timber Bureau. Illustrations of the bud and fruits of Eucalyptus species with an alphabetical index (covering 486 species, and varieties). 2nd ed. pp. (ix) 31 pls. fol. Canberra. 1954. Grasses and pastures of South Africa. Compiled by L.K.A. Chippindall, J.D. Scott, J.A. Pentz, A.W. Bayer, O. West, H. Weinmann, and others. 26 col. pls and 420 line drawings, 776 pp. 1955.

Description: In the Synopsis of Proposals for the Botanical Congress at Montreal Dr Lanjouw has in his capacity of Rapporteur général given his well-considered opinion on each proposal, except for that on nomina specifica conservanda where he found fit to postpone his comment. There are three proposals on which I cannot follow his advice. These three instances are the following.