This article was downloaded by: [121.41.15.122] On: 26 August 2015, At: 17:26 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: 5 Howick Place, London, SW1P 1WG Grana Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/sgra20 Sem Studies on Pollen Grains of North European Ulmus Species Jens Stockmarr a a Geological Survey of Denmark, Copenhagen, Denmark Published online: 01 Sep 2009. To cite this article: Jens Stockmarr (1974) Sem Studies on Pollen Grains of North European Ulmus Species, Grana, 14:2-3, 103-107, DOI: 10.1080/00173137409429900 To link to this article: http://dx.doi.org/10.1080/00173137409429900 PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the Content ) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/termsand-conditions
Grana 14: 103-107, 1974 SEM STUDIES ON POLLEN GRAINS OF NORTH EUROPEAN ULdlUS SPECIES Jens Stockmarr (Received September 20, 1974) Downloaded by [121.41.15.122] at 17:26 26 August 2015 ABSTRACT Stockmarr, J. (Geological Survey of Denmark. Copenhagen, Denmark). SEhlsfudics onpollengrains of h orfh European Ulmrrs species. Grana 14: 103-107, 1974.-PoIIen grains of Ulmtcs glabra. U. lacris. U. nrinor and U. prorero have been studied in a scanning electron microscope. The pollen grains are heteropolar with a smooth proximal polar area and a rough sculptured distal polar area. In the equatorial belt the interporal regions have distinct sculpturing and are bordered by low ridges. The pollen of four elm spe$es, which were treated statistically by Stockmarr (1970), has been investigated in a scanning electron microscope. The purpose was to search for differences between the four species that could be used for separation in pollen analysis. MATERIAL AND METHODS All the specimens were investigated in both scanning electron and light microscopes (Stockmarr, 1970). The investigated pollen was acetolysed, dried and coated with carbon and gold. The pollen of Ultiais procera was transferred from silicone oil, from which it could not be completely cleaned. The micrographs were exposed in JEOL SEM model S1 at an accelerating voltage of 10 kv, with magnifications of x 3 000, x 5 000 and x 10 000. Photographic assistance was given by 0. Neergaard Rasmussen at the Geological Survey of Denmark. The plates do not show the full range of the shape and sculpturing in the pollen of the four species, but the grains chosen are good representatives of the species. S~ecitne~rs iticestigated Ulrrrus globro Huds.: Denmark, Lolland, Coll.? (Ref. coll. Geol. Surv.); Vordingborg. Fredskild 35.1966 (C). Sweden, eland. Sfockrrtorr 9.3.1973 (PI. I: 1. 5. PI. 2: I. I A. PI. 3: I, 1 A). Great Britain, Pill Abbotsleigh. Coll.? 10.3.1918 (B1 R hl). Ulnrus laeris Pall.: Denmark, Boserup, frerscn (Ref. coll. Geol. Surv.); Krenkerup, Srocknrorr anno 1970 (PI. I: 2, PI. 2: 2, 2A. PI. 3: 2, 2A); Vigsnas. Srockitrarr 22.4.1968. Austria, Vindobonam, Coll.? (K). Germany, Brandenburg, Coll.? (K). Belgium, Coll.? (K). Ulnrus minor Mill.: Denmark, Falster. Coll.?; SamsS, 29.4.1966 (Ref. coll. Geol. Surv.). Sweden, eland, Sforlrtnarr 10.3.1973 (PI. I: 3. PI. 2:3, 3A, PI. 3: 3, 3A), Sfocknrarr 9.3.1973. Netherlands, Norg, Co11.7 (Ref. coll. Geol. Surv. Denmark). Ulrirics proccro Salisb.: Denmark, Lolland, Srorknrarr 28.4. 1969. Great Britain, Leicestershire, Tufin & Sforkniurr 21.4.1969 (PI. 1:4, 6, PI. 2:4, 4A, PI. 3:4. 4A). Surrey, Wallacr 5.4.1942 (K), IVallncr 5.4.1942 (K). Vernham Dean, Coll.? (K). RESULTS The pollen grains of the Ultniis species arc distinctly heteropolar (Andrew, 1971 ; paraisopolar, Praglowski, 1962; Plate l), with a rough distal polar area (Plate 2) and a smoother proximal polar area (Plate 3). Similar heteropolarity is found in Tilia Plafe 1. Equatorial views of Ulnius glabro (I). U. loeris (2). U. minor (3) and U. prorcra (4). The arrows in no. I point to the ridges bordering the interporal regions. The pollen grain of U. laeris seems to have a hidden undeveloped pore right at the top. Distal pole to the right. x 2 250. - (5) U. glabra. The thin-walled proximal polar area has cavcd in. x 2 250. - (6) U. procero. Wall structure, seen in a broken grain. x 3 750 and x 7 500. Plafe 2. Distal polar areas of Ulnrus glabra (I. 1 A), U. lacris (2, 2A). U. minor (3,3A) and U. procera (4.4A). The micrographs taken at the higher magnifications (IA-4A) show different grains. x 2 250 and x 7 500. P-....
104 Jeiu Srockniarr
Polleir grains of Ulmiis species 10s Grana 14
106 Jem Slockmarr
(Praglowski, 1962; Stockmarr, 1974) and many spores, e.g. Lycopodiiim spores. The sculpturing of the distal polar area in Ulririrs procera is coarsely rugulose, having been described as rugulose to irregularly supra-reticulate by Fregri & lverscn (1964). U. glabra and U. laecis cannot he separated by their sculpturing, which in both species varies between those shown in Plate 2: 1 and 2. The sculpturing of U. niiiior cannot be distinguished from that of U. glabra and U. laecis, but is generally slightly smoother. The proximal polar area has sculpturing which may vary from smoothly rugulate to almost verrucate in all four species, and the whole grain is covered by a great number of very smallprocesses,which seem tocorrespond to the number of structuralelements within the wall (Plate 1: 6). Many grains collapsed when they were dried on the stub, and in most cases the proximal polar area caved in (Plate 1 : 5). This indicates that the proximal polar area has a thinner wall than thedistal one. The apertures are called pores although, owing to their oblong form, they are sometimes very short furrows. The equatorial area is very interesting. The interporal regions have finer, but not less marked, sculpturing than the distal polar area. Towards the proximal pole, they are bordered by a low ridge formed by particularly high and rough sculptural elements, The ridge is further cniphasized by the contrast with the finely sculptured polar area. Towards the distal pole, the transition from the interporal regions to the polar area appears as a vague false ridge, because the interporal regions are slightly flattened, forming an edge with the polar area. This gives UImirs pollen a more or less angular shape. In U. minor these features arc less pronounced, and the pollen grains appear more rounded in polar view than in the other species (Plates 2 and 3). The pores are surrounded by an annulus-like structure, which is less pronounced in U. niiiror than in the other species. PIoir 3. Proximal polar areas of Ulnriis glabra (I. IA). U. Iaeris (2, 2A), U. nrinor (3. 3A) and U. procrra.(4, 4A). x 2 250 and x 7 500. Pollen grniirs of Ulinirs species 107 The wall structure is interesting. It has not been possible to distinguish the endexine with certainty (Plate 1: 6). The whole wall seems to be built up by a spongy mass of regularly orientated granules, which are united in a tectum at the top (cf. densely spaced bacula, Praglowski, 1962; Ueno, 1963). 'fhe wall structure was seen only in U. procera. All the sculptural features, except the very small processes, can be seen in the light microscope, too, although the ridges are not easy to discern. Ulmirs procera pollen grains are slightly angular and can be distinguished from the other species by their roughly rugulate sculpturing in the proximal polar area and large number of pores (Stockmarr, 1970). U. miiior pollen grains are rounded, lack well-developed annuli and have interporal regions that do not differ greatly from the distal polar area. However, U. mbor pollen grains are still very difficult to distinguish fiom U. glabru grains, which have similar sculpturing and almost thc same number of pores. U. glabra and U. laecis have somewhat angular pollen grains with well-developed interporal regions and similar sculpturing, but they may be separated by statistics on the number of pores (Stockmarr, 1970). REFERENCES Andrew. R. 1971. Exine pattern in the pollen of British species of Tilia. - New Phytol. 70: 683-686. Fsgri, K. & Iversen. J. 1964. Textbook of pollen analysis, 2nd ed.. 237 pp. - Copenhagen. Praglowski, J. R. 1962. Notes on the pollen morphology of Swedish trees and shrubs. - Grana Palynol. 3 (2): 45-65 + 54 PIS. Stockmarr. J. 1970. Species identification of Ulmus pollen. - Danm. Geol. Unders. IV (4) 11. 19 pp. - 1974. Scanning electron micrographs of pollen grains from two Tilia species. - Danm. Geol. Unders., Arbog 1973: 99-101 i 4 PIS. Ucno, J. 1963. On the fine structure of the pollen walls of Angiosmermae. 111. Casuarina. - Grana Palynol. 4 (2): 189-1 94. lens Siockirrarr Geological Siirrrj of Dentnark Tliorarej 31 2400 Copenhagen N V Dennrark Gratin 14