@article{DrenckhahnZonneveld2017,
  author    = {Drenckhahn, Detlev and Zonneveld, Ben},
  title     = {Rubus viridilucidus Drenckhahn, eine neue Brombeerart aus der Sektion Corylifolii, Serie Subcanescentes},
  series = {Forum Geobotanicum},
  volume    = {7},
  journal   = {Forum Geobotanicum},
  issn      = {1867-9315},
  doi       = {10.3264/FG.2017.1221},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-156257},
  pages     = {34-42},
  year      = {2017},
  abstract  = {Rubus viridilucidus Drenckhahn ist eine tetraploide Brombeerart (2n=28) aus der Sektion Corylifolii, Serie Subcanescentes mit einem Genomgewicht (2C-Wert) von 1,49 pg, das dem Genomgewicht verwandter Sippen der Serie Subcanescentes wie R. scabrosus, R. fasciculatiformis und R. fasciculatus (1,52-1,54 pg) aus Unterfranken entspricht. Charakteristische Merkmale sind 3-4(5)-z{\"a}hlige Bl{\"a}tter mit herab gekr{\"u}mmten rundlichen bis breit obovaten Endbl{\"a}ttchen und breitovalen Seitenbl{\"a}ttchen, die eine v{\"o}llig unbehaarte, lichtgr{\"u}ne, mattgl{\"a}nzende Blattoberfl{\"a}che besitzen mit kontrastierender hell gr{\"u}nlich-grauer, samtig behaarter Blattunterseite. Die {\"u}berwiegend rundlichen bis stumpf kantigen, lichtgr{\"u}nen bis r{\"o}tlich {\"u}berlaufenen Sch{\"o}sslinge sind unbehaart und sp{\"a}rlich mit kurzen (<4mm) nadelf{\"o}rmigen Stacheln und wenigen Stieldr{\"u}sen besetzt. R. viridilucidus entwickelt zus{\"a}tzlich zu den Bl{\"u}tenzweigen der zweij{\"a}hrigen Sch{\"o}sslinge (Ausbreitungssch{\"o}sslinge) einen besonderen bl{\"u}henden 0,8 bis 1,6 m langen Sch{\"o}sslingstyp aus, den Rispensch{\"o}ssling, der direkt aus dem Wurzelstock entspringt und terminal in eine Bl{\"u}tenrispe ausl{\"a}uft. Bei R. viridilucidus sind zwei verschiedene Typen von Rispensch{\"o}sslingen ausgebildet. Die Sippe w{\"a}chst bevorzugt auf gest{\"o}rten Fl{\"a}chen wie Brachen, Straßenr{\"a}ndern, Lagerpl{\"a}tzen, Weinbergr{\"a}ndern und kann sich mit 1-2 m j{\"a}hrlichem Zuwachs (Satellitenbildauswertung, Vermessungen vor Ort) schnell ausbreiten. Die bekannt gewordenen Fundstellen erstrecken sich vom n{\"o}rdlichen Baden-W{\"u}rttemberg bis in den n{\"o}rdlichsten Teil von Bayern (Rh{\"o}n).},
  subject      = {Brombeere},
  language  = {de}
}
@misc{DrenckhahnBaumgartnerZonneveld2017,
  author    = {Drenckhahn, Detlev and Baumgartner, Werner and Zonneveld, Ben},
  title     = {Forum Geobotanicum Vol. 7 (2016/2017)},
  volume    = {7(2016/2017)},
  editor    = {Meierott, Lenz and Drenckhahn, Detlev and Dunkel, Franz G. and Ewald, J{\"o}rg and Schuhwerk, Franz},
  issn      = {1867-9315},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-157381},
  year      = {2017},
  abstract  = {Forum Geobotanicum is an electronic journal devoted to disseminate information concerning geographical distribution, ecology, morphology, taxonomy and conservation of vascular plants in the European Union with a main focus on middle Europe. It covers from molecular biology to environmental aspects. The focus is to publish original papers, reviews and announcements for the educated generalist as well as the specialist in this broad field. Forum Geobotanicum does not aim to supplant existing paper journals, but will be much more flexible in format, publication time and world-wide distribution than paper journals. Many important studies are being currently published in local journals and booklets and some of them are published privately. Hence, these studies will become aware to only a limited readership. Forum Geobotanicum will encourage authors of such papers to submit them as special issues of the journal. Moreover, the journal is planning to build up an E-mail-address section to support communication between geobotanists in Europe. The editors are optimistic that this electronic journal will develop to a widely used communication forum that will help to stimulate activities in the entire field of geobotany in middle Europe. To overcome problems of long term archivation and effective taxonomic publication of articles published electronically in Forum Geobotanicum, print versions of each volume of the journal and appropriate digital storage devices will be delivered freely to selected university libraries and state libraries in middle Europe.},
  language  = {mul}
}
@article{DrenckhahnBaumgartnerZonneveld2017,
  author    = {Drenckhahn, Detlev and Baumgartner, Werner and Zonneveld, Ben},
  title     = {Different genome sizes of Western and Eastern Ficaria verna lineages shed light on steps of Ficaria evolution},
  series = {Forum Geobotanicum},
  volume    = {7},
  journal   = {Forum Geobotanicum},
  issn      = {1867-9315},
  doi       = {10.3264/FG.2017.1122},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-155061},
  pages     = {27-33},
  year      = {2017},
  abstract  = {The genus Ficaria is now considered to comprize eight Eurasian species. The most widespread European species is the tetraploid F. verna Huds. The present study provides evidence for the existence of two main lineages of F. verna that differ considerably in their genomic size by about 3 pg. A Western F. verna lineage west of river Rhine displays a mean genome size (2C-value) of 34.2 pg and is almost precisely codistributed with the diploid F. ambigua Boreau (20 pg) north of the Mediterranean. The remaining part of Europe appears to be occupied by the Eastern F. verna lineage solely (mean genome size of 31.3 pg) which codistributes in South-Eastern Europe with the diploid F. calthifolia Rchb. (15 pg). There is little overlap at the boundary of Western and Eastern F. verna lineages with the occurrence of a separate intermediate group in the Netherlands (mean genomic size of 33.2 pg) that appears to result from hybridization of both lineages. On the basis of these observations and further considerations we propose development of F. ambigua and F. calthifolia south of the Alps with subsequent divergence to populate their current Western and Eastern European ranges, respectively. The Western F. verna lineage is proposed to originate from autotetraploidization of F. ambigua (precursor) with moderate genomic downsizing and the Eastern F. verna lineage from auto¬tetraploidization of F. calthifolia (precursor).},
  subject      = {Durchflusscytometrie},
  language  = {en}
}
@article{Zonneveld2019,
  author    = {Zonneveld, Ben J. M.},
  title     = {The DNA weights per nucleus (genome size) of more than 2350 species of the Flora of The Netherlands, of which 1370 are new to science, including the pattern of their DNA peaks},
  series = {Forum Geobotanicum},
  volume    = {8},
  journal   = {Forum Geobotanicum},
  issn      = {1867-9315},
  doi       = {10.3264/FG.2019.1022},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-189724},
  pages     = {24-78},
  year      = {2019},
  abstract  = {Besides external characteristics and reading a piece of DNA (barcode), the DNA weight per nucleus (genome size) via flow cytometry is a key value to detect species and hybrids and determine ploidy. In addition, the DNA weight appears to be related to various properties, such as the size of the cell and the nucleus, the duration of mitosis and meiosis and the generation time. Sometimes it is even possible to distinguish between groups or sections, which can lead to new classification of the genera. The variation in DNA weight is also useful to analyze biodiversity, genome evolution and relationships between related taxa. Moreover, it is important to know how large a genome is before one determines the base sequence of the DNA of a plant. Flow cytometry is also important for understanding fundamental processes in plants such as growth and development and recognizing chimeras. In the literature, DNA weight measurements are usually limited to one genus and often only locally (Siljak et al. 2010; Bai et al. 2012). In this study, however, it was decided to investigate all vascular plants from one country. This can also contribute to the protection of rare plants. This study is the first flora in the world whose weight of DNA per nucleus and peak patterns has been determined. More than 6400 plants, representing more than 2350 (sub)species (more than 90\%) have been collected, thanks to the help of almost 100 volunteers of Floristisch Onderzoek Nederland (Floron). Multiple specimens of many species have therefore been measured, preferably from different populations, in some cases more than fifty. For 1370 species, these values were not previously published. Moreover, a good number of the remaining 45\% are new for The Netherlands. In principle, each species has a fixed weight of DNA per nucleus. It has also been found that, especially between the genera, there are strong differences in the number of peaks that determine the DNA weight, from one to five peaks. This indicates that in a plant or organ there are sometimes nuclei with multiples of its standard DNA weight (multiple ploidy levels). It is impossible to show graphs of more than 2350 species. Therefore, we have chosen to show the peak pattern in a new way in a short formula. Within most genera there are clear differences in the DNA weights per nucleus between the species, in some other genera the DNA weight is hardly variable. Based on about twenty genera that were previously measured completely in most cases ('t Hart et al. 2003: Veldkamp and Zonneveld 2011; Soes et al. 2012; Dirkse et al. 2014, 2015; Verloove et al. 2017; Zonneveld [et al.] 2000-2018), it can be noted that even if all species of a genus have the same number of chromosomes, there can still be a difference of up to three times in the weight of the DNA. Therefore, a twice larger DNA weight does not have to indicate four sets of chromosomes. Finally, this research has also found clues to examine further the current taxonomy of a number of species or genera.},
  subject      = {Pflanzen},
  language  = {en}
}
@article{DrenckhahnZonneveld2022,
  author    = {Drenckhahn, Detlev and Zonneveld, Ben},
  title     = {Rubus admirabilis Drenckhahn, eine neue Brombeerart aus dem Formenkreis der Serie Vestiti an der Westk{\"u}ste von Schleswig-Holstein, Deutschland},
  series = {Forum Geobotanicum},
  volume    = {10},
  journal   = {Forum Geobotanicum},
  issn      = {1867-9315},
  doi       = {10.3264/FG.2022.1228},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-298658},
  pages     = {38-44},
  year      = {2022},
  abstract  = {Rubus admirabilis Drenckhahn is a tetraploid new species of the Rubus section Rubus, series Vestiti. Stem leaves are 5-foliolate, digitate to weakly pedate with elongated, obovate acuminate terminal leaflets, adpressed hairy upper side and light green shimmering, softly hairy under side. Stems are arching (up to 2 m) partly climbing, obtuse-angled, densely hairy and glandular, gray green to dull brown, armed with 10(3-21) /5cm straight slender prickles, mostly 30-45º declining, 4.6(3-7)mm long. Pedicles of inflorescence are densely hairy (patent and partly adpressed), armed with 2-4 (per cm) slender patent to slightly curved prickles (1-2 mm long) and studded with numerous stalked glands (0.3-0.5 mm long) and some bristles. The species tolerates shadow and prefers moist soil. The type locality is probably the species' site of introduction or genesis. It is located west of the town Garding on the North Frisian peninsula of Eiderstedt (several hundred shrubs), where several non-native Rubus species were probably introduced in the course of reforestation in 1970. Rubus admirabilis spreads south to the town of Heide in Dithmarschen and north to the island of Amrum (maximal range diameter of 70 km) and seems to be in an expansive phase.},
  subject      = {Brombeere},
  language  = {de}
}
@misc{DunkelDrenckhahnZonneveld2022,
  author    = {Dunkel, Franz G. and Drenckhahn, Detlev and Zonneveld, Ben},
  title     = {Forum Geobotanicum 10 (2021/2022)},
  volume    = {10(2021/2022)},
  editor    = {Meierott, Lenz and Drenckhahn, Detlev and Dunkel, Franz G. and Ewald, J{\"o}rg and Fleischmann, Andreas},
  issn      = {1867-9315},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-298926},
  year      = {2022},
  abstract  = {Forum Geobotanicum is an electronic journal devoted to disseminate information concerning geographical distribution, ecology, morphology, taxonomy and conservation of vascular plants in the European Union with a main focus on middle Europe. It covers from molecular biology to environmental aspects. The focus is to publish original papers, reviews and announcements for the educated generalist as well as the specialist in this broad field. Forum Geobotanicum does not aim to supplant existing paper journals, but will be much more flexible in format, publication time and world-wide distribution than paper journals. Many important studies are being currently published in local journals and booklets and some of them are published privately. Hence, these studies will become aware to only a limited readership. Forum Geobotanicum will encourage authors of such papers to submit them as special issues of the journal. Moreover, the journal is planning to build up an E-mail-address section to support communication between geobotanists in Europe. The editors are optimistic that this electronic journal will develop to a widely used communication forum that will help to stimulate activities in the entire field of geobotany in middle Europe. To overcome problems of long term archivation and effective taxonomic publication of articles published electronically in Forum Geobotanicum, print versions of each volume of the journal and appropriate digital storage devices will be delivered freely to selected university libraries and state libraries in middle Europe.},
  subject      = {Geobotanik},
  language  = {de}
}
@article{GottschlichDrenckhahnMeierottetal.2023,
  author    = {Gottschlich, G{\"u}nter and Drenckhahn, Detlev and Meierott, Lenz and Zonneveld, Ben},
  title     = {Hieracium maculatum subsp. pseudogougetianum, eine neue Unterart aus dem Mainfr{\"a}nkischen Muschelkalkgebiet},
  series = {Forum Geobotanicum},
  volume    = {11},
  journal   = {Forum Geobotanicum},
  issn      = {1867-9315},
  doi       = {10.3264/FG.2023.0923},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-327601},
  pages     = {15-20},
  year      = {2023},
  abstract  = {In Lower Franconia/Northern Bavaria, a well-defined subspecies of the Hieracium maculatum group was detected. This subspecies is restricted to the slopes of the Main valley between W{\"u}rzburg and Hasloch with a hot spot (>90\% of total population) between the villages Th{\"u}ngersheim and Retzbach. Due to some similarities with H. glaucinum subsp. prasiophaeum (synonym: subsp. gougetianum) the subspecies is named H. maculatum subsp. pseudogougetianum. This subspecies grows preferentially on shell-bearing limestone gravels and begins flowering as early as mid-April. Head involucra are whitish hairy mixed with dark stalked glands. The basal leaf rosette consists of ovate to elliptic, toothed to serrate, dark spotted leaves, glabrous, glaucous above. Stems bear 1-3(4) stalked stem leaves and usually form long lateral flowering branches from the leaf axils. Like some other H. maculatum subspecies, H. maculatum subsp. pseudogougetianum is tetraploid with a mean genome weight (2C value) of 14.5 pg, distinguishing it from the H. glaucinum group, whose studied taxa are invariably triploid (mean 10.1 pg).},
  subject      = {Korbbl{\"u}tler},
  language  = {de}
}
@article{DrenckhahnGottschlichZonneveld2023,
  author    = {Drenckhahn, Detlev and Gottschlich, G{\"u}nter and Zonneveld, Ben},
  title     = {Neubeschreibungen und 2C-Werte von Pilosella macranthela subsp. silvae-pici (Spessart-Mausohrhabichtskraut) und Pilosella ottonis (Otto-Mausohrhabichtskraut) mit einer {\"U}bersicht {\"u}ber das Vorkommen von P. macranthela-Taxa in Bayern.},
  series = {Forum Geobotanicum},
  volume    = {11},
  journal   = {Forum Geobotanicum},
  issn      = {1867-9315},
  doi       = {10.3264/FG.2023.1114},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-344797},
  pages     = {21-34},
  year      = {2023},
  abstract  = {A pentaploid taxon from the Pilosella macranthela group was discovered in Lower Franconia/Bavaria which is newly described here as P. macranthela subsp. sylvae-pici. It grows mainly in the Bavarian Bunter Spessart and occurs with three small, isolated stands also in the limestone area of the Main valley and Tauber area. Its habit of growth is intermediate between the furcata and laxicephala types of Pilosellae with epigeal and partly hypogeal stolons and a tendency to form clusters. The upper and lower surfaces of the rosette leaves have stellate hairs. The peduncles and the phyllaries are densely covered with dark glandular hairs with yellowish glandular heads. The lateral teeth of the ligules often are separated by incisions. A tetra- und pentaploid transitional taxon between P. macranthela subsp. sylvae-pici and P. officinarum is described as P. ottonis. P. ottonis is tetra- and pentaploid with up to 7 capitula. It is densely covered with dark stalk glands on phyllaries and resembles forms of P. acutifolia in habit. The phyllaries of P. ottonis are covered with numerous epidermal papillae with a diameter of about 10-20 μm and in this aspect resemble P. macranthela subsp. sylvae-pici and P. glomerata. However, in P. officinarum epidermal papillae are absent. Plants of genetically heterogeneous tetra- and heptaploid P. macranthela have been found outside the Spessart as spontaneous hybrids between P. glomerata and P. officinarum and also occur sporadically without P. glomerata in the vicinity.},
  subject      = {Habichtskraut},
  language  = {de}
}