Mike Thiv

• State Museum of Natural History Stuttgart

The Macaronesian laurel forests (MLF) are dominated by trees with a laurophyll habit comparable to evergreen humid forests which were scattered across Europe and the Mediterranean in the Paleogene and Neogene. Therefore, MLF are traditionally regarded as an old, 'Tertiary relict' vegetation type. Here we address the question if key taxa of the MLF...

Auf Einladung des Bundesamtes für Naturschutz (BfN) trafen sich vom 20. bis 21. Oktober 2023 in Bonn Vertreterinnen und Vertreter von Bundes- und Ländereinrichtungen, botanischen Fachverbänden und Forschungsinstituten im Rahmen einer Konferenz zur Floristischen Kartierung in Deutschland. Dabei formulierten die Unterzeichnenden den Handlungsbedarf u...

A growing number of farmers’ cooperatives cultivate crops without chemical pesticides, but also without organic certification. How does this intermediate form of agriculture between conventional and organic production function? What are the outcomes of this production form on cropland biodiversity? How does this model contribute to the transition t...

Alyssum montanum and A. gmelinii were often treated as subspecies of A. mont-anum s.l. Based on molecular and morphological data, the traditional distinction between the two taxa resting upon ecological differentiation had been replaced by geographic definitions of the species. Accordingly, A. montanum occurs in France, Switzerland and SW Germany w...

The taxonomy of the Mediterranean Aristolochia pallida complex has been under debate since several decades with the following species currently recognized: A. pallida, A. lutea, A. nardiana, A. microstoma, A. merxmuelleri, A. croatica, and A. castellana. These taxa are distributed from Iberia to Turkey. To reconstruct phylogenetic and biogeographic...

Macaronesian laurel forests harbour many herbs and laurophyllous trees with Mediterranean/European or Macaronesian affinities. Traditionally, the origin of these taxa has been explained by the relict hypothesis interpreting these taxa as relics of formerly widespread laurel forests in the European continent and the Mediterranean. We analysed the ph...

Plants, fungi and algae are important components of global biodiversity and are fundamental to all ecosystems. They are the basis for human well-being, providing food, materials and medicines. Specimens of all three groups of organisms are accommodated in herbaria, where they are commonly referred to as botanical specimens. The large number of spec...

Printed 2020

The distinction of the perennial Aristida coerulescens from the annual A. adscensionis and its taxonomic treatment has been subject of long discussions. We here include accessions from the Mediterranean and Macaronesia for molecular phylogenetic analyses and conducted a morphometric analysis. A lineage of A. adscensionis, A. coerulescens and A. eff...

We investigate patterns of genetic variation along an east–west transect of Central European populations of Linum flavum and interpret the Quaternary history of its peripheral populations, especially those at the westernmost isolated range edge, discussing their migrations and possible relict status. We defined our peripheral transect across three...

This work is the continuation of Part 1, published in 2015, and comprises the reconstruction of the original collections of new taxa described by R. Pampanini and other botanists and, where possible, typification of the new names and taxonomical updating. The material studied for the most part concerns Libyan specimens held in the FI and FI-W herba...

Extinction of biodiversity due to human activities is a severe global problem. In Europe, however, only a few plant species died out so far. We investigated a dubious, disregarded taxon—Saxifraga oppositifolia subsp. amphibia—which became extinct in the 1960s. It exclusively occurred in a specific niche, namely in seasonally flooded waterside bank...

Background and Aims Macaronesian laurel forest is among the worldwide hotspots of threatened biodiversity. With increasing evidence that woodland composition on the Canary Islands changed dramatically during the last few thousand years, the aim of this study was to find evidence for substantial recent population dynamics of two representative speci...

Many Central European weeds were introduced in conjunction with increasing agricultural activities during the Neolithic period. Others likely originated in situ during crop domestication and selection. Among the European weeds occurring primarily in cereal fields are three tetraploid members of the genus Bromus (Poaceae), Bromus secalinus L. associ...

Evergreen shrubs or trees up to 25 high. Leaves alternate, opposite to subopposite, or pseudo-whorled, petiolate, exstipulate (present, minute?), simple, coriaceous, entire to glandular-dentate, penninerved. Inflorescences axillary or terminal racemes, bracteate at base, floral bracts caducous. Flowers hermaphrodite or rarely unisexual, actinomorph...

Annual or perennial, erect, branched herbs or subshrubs, glabrous or pubescent; nodes unilacunar. Leaves opposite, sessile to subsessile, exstipulate, simple, ovate to linear, entire. Inflorescences axillary, of paired, small hermaphrodite, actinomorphic flowers. Perianth with distinct pentamerous calyx and corolla; calyx lobes valvate; petals free...

The main trends in changes in the global vascular plant biodiversity are generally considered to be a decrease in rare indigenous species and a spread of invasive plants. In the present paper, the impact of these changes on the flora of the state of Baden-Württemberg (Southwest-Germany) is examined. The data come from a regional floristic mapping p...

Figure S1. Assessment of the most likely number of clusters of structure runs using the method of Evanno et al. (2005) for Aeonium davidbramwellii. Figure S2. Correlation of pair‐wise geographic distance and pair‐wise linearised F ST between populations of Aeonium davidbramwellii: Mantel's R = 0.270, P = 0.082. Figure S3. Assessment of the most l...

Table S1. Plate layout and instrument settings for DNA purification via BindIT 3.1 KingFisher software. Table S2. Tested primers for the ISSR analyses, their sequences and PCR annealing temperatures. Table S3. Combined results of outlier loci detection methods for Aeonium nobile.

The Crassulacean genus Aeonium is a well-known example for plant species radiation on oceanic archipelagos. However, while allopatric speciation among islands is documented for this genus, the role of intra-island speciation due to population divergence by topographical isolation or ecological heterogeneity has not yet been addressed. The aim of th...

Environmental dynamics had a great impact in Europe during the Pleistocene. Climatic changes and ice age fluctuations were followed by changes in vegetation composition. The effects of Pleistocene dynamics are less known for Macaronesia. Dust proxies indicate a shift of climatic conditions on the Canary Islands during the Upper-Pleistocene glacials...

The worldwide distributed Lauraceae with diversification centres in tropical regions comprise about 3000 species. Important elements of the Macaronesian laurel forest belong to this plant family. These species were traditionally regarded as old Tertiary relicts. They serve as key taxa for the understanding of the evolution of this specific vegetati...

Macaronesia harbours many endemics and is part of the Mediterranean Basin hotspot. Close links between the Macaronesian and the Mediterranean flora have been proposed. A Mediterranean origin has been found, e.g., for the Macaronesian endemic Ixanthus. Other endemic genera are Visnea and Gesnouinia. Visnea is a monotypic genus belonging to the mainl...

Macaronesia has been traditionally recognized as a distinct biogeographic unit consisting of five Atlantic volcanic archipelagos: Azores, Madeira, Salvage Islands, Canary Islands, and Cape Verde Islands. Unique climate and geological conditions on these islands are essential for survival of highly specialized vegetation types, like the Macaronesian...

Macaronesia has been traditionally recognised as a distinct biogeographic unit consisting of the five Atlantic volcanic archipelagos, Azores, Madeira, Salvage Islands, Canary Islands, and Cape Verde Islands. Several authors implicitly challenged the concept of Macaronesia by classifying the floras of the different archipelagos to distinct biogeogra...

European annual species of the genus Rhinanthus often exhibit seasonal ecotypic variation, a phenomenon also known from related genera of hemiparasitic Orobanchaceae. Populations with different flowering times exist, correlated with differences in a number of morphological characters. The present study evaluates the correlation of morphological cha...

A revised phylogeny of Tylophorinae, based on 77 species of all genera presently attributed to the subtribe (Biondia, Blyttia, Diplostigma, Goydera, Pentatropis, Pleurostelma, Rhyncharrhena, Tylophora, Vincetoxicum) is presented. Five chloroplast markers (trnT-L, trnL-F, and psbA-trnH intergenic spacers as well as the trnL and trnG introns) and two...

"Laurisilva or laurel forests are found on several Macaronesian islands including Madeira, the Azores and the Canary Islands. This vegetation type is thought to represent a relict of a vegetation type which originally covered much of the Mediterranean Basin when the climate of the region was more humid. Our project evaluates whether laurel forest...

"Lauraceae are important elements of the laurel forest. They can be seen as key taxa for the understanding of evolution of this specific vegetation type. The following questions are addressed: When did Macaronesian Lauraceae evolve, where did they come from and what are the biogeographic inter- and innerarchipelago relationships? Molecular phyl...

Alyssum montanum subsp. montanum and A. montanum subsp. gmelinii have been treated as two largely sympatric taxa that occur throughout the European continent. The former was regarded to grow on calcareous and serpentine rocks and in dry grasslands, and the latter mostly on sand dunes. In this study, we demonstrate that the traditional delimitation...

Three unidentified populations of Gagea recorded during the floristic mapping of Baden-Württemberg (Southwest -Germany) were analysed using molecular and morphological methods. One of them proved to be a form of Ga-gea villosa. The second population was primarily classified as G. pomeranica based on morphological characters. The molecular results,...

The little known Rubiaceae genus Villaria is endemic mostly to the coastal forests of the Philippines. Traditionally, it has been placed in the tribe Gardenieae. Later it was transferred to Octotropideae sensu Robbrecht and Puff. Villaria was placed among the “primitive” genera of the tribe, which are essentially characterized by large fruits, hori...

The succulent biome is highly fragmented throughout the Old and New World. The resulting disjunctions on global and regional scales have been explained by various hypotheses. To evaluate these, we used Thamnosma, which is restricted to the succulent biome and has trans-Atlantic and trans-African disjunctions. Its three main distribution centers are...

Greeniopsis Merr. is a small genus of Rubiaceae endemic to the Philippines. Previously, no molecular data have been available for Greeniopsis and its taxonomic position has remained controversial. Based on morphology, the genus was tentatively included in the tribe Aleisanthieae (Ixoroideae) along with the Southeast Asian genera Aleisanthia and Ale...

Greeniopsis Merr. is a small genus of Rubiaceae endemic to the Philippines. Previously, no molecular data have been available for Greeniopsis and its taxonomic position has remained controversial. Based on morphology, the genus was tentatively included in the tribe Aleisanthieae (Ixoroideae) along with the Southeast Asian genera Aleisanthia and Ale...

Oceanic islands frequently harbour prominent examples of plant radiations. Here, we investigated the Macaronesian Crassulaceae-Sempervivoideae (MCS) including the genera Aichryson, Monanthes and Aeonium. This species-rich clade displays a large variety in morphological and ecological features, and is, therefore, often considered as adaptive radiati...

It is still unknown what exact role interspecific gene flow and reticulate patterns of gene transfer may play in adaptive radiations. To contribute to a better understanding of gene flow in a morphologically diverse and species-rich lineage, we investigated pollen transfer in the adaptively radiated Macaronesian Crassulaceae-Sempervivoideae. We aim...

The Podostemaceae are highly enigmatic plants which are restricted to submerged river-rock habitats. The availability of new material of nine taxa from continental Africa prompted this new study. Five species belonging to the genera Dicraeanthus, Leiothylax, Letestuella, Macropodiella, and Stonesia and another four species of the large genera Inver...

The numerous disjunct plant distributions between Macaronesia and eastern Africa-Arabia suggest that these could be the relicts of a once continuous vegetation belt along the southern Tethys, which has been fragmented by Upper Miocene-Pliocene aridification. We tested this vicariance hypothesis with a phylogenetic analysis of Campylanthus (Plantagi...

The traditional circumscription of the genus Stonesia G. Taylor (Podostemaceae, Podostemoideae) includes three species restricted to western tropical Africa. Here, a new species, S. ghoguei E. Pfeifer & Rutishauser, is described, which represents the first Cameroonian member of the genus. There are another three Stonesia species restricted to weste...

The applicability of “inter-simple sequence repeats” (ISSR)-PCR as a molecular character complex for differentiation of Equisetum taxa is described with a special focus on the detection of hybrids. All Central European Equisetum species and the four most frequent hybrids are considered: E. arvense, E. fluviatile, E. telmateia, E. palustre, E. sylva...

We investigated the phylogeny, taxonomy and biogeography of the Eritreo-Arabian genus Echidnopsis Hook. f. (Apocynaceae-Asclepiadoideae). Phylogenetic reconstructions based on nrITS sequence data were obtained using maximum likelihood and parsimony analyses. The results reveal two weakly supported clades, each with a mix of African and Arabian taxa...

The Podostemaceae (eudicots, Malpighiales) are adapted to rivers that exhibit distinct high-low water seasonality, mainly in the tropics. They attach to submerged rocks with ribbonlike or crustose green roots that cover the substrate like a carpet. Pronounced root dorsiventrality resulted in disklike crusts lacking root caps. African Podostemoideae...

We investigated the colonization of the Indian Ocean archipelago of Socotra through phylogenetic analysis of Aerva (Amaranthaceae) based on nuclear and plastid DNA sequence data. The biogeographic history of the genus was tracked using ancestral area reconstructions and molecular dating. Three independent colonization lineages from the Eritreo-Arab...

Perennial herbs or shrubs. Leaves opposite, petiolate, simple, elliptic to ovate, acuminate, pinnately nerved, dentate or crenate-serrate, estipulate. Flowers in axillary or terminal cymes, pedicellate or (sub)sessile, hermaphrodite, zygomorphic to subregular, sometimes heterostylous. Calyx tube adnate to the ovary; lobes 4 or 5, unequal, persisten...

A taxonomic revision of all genera belonging to Gentianaceae–Canscorinae, i.e., Canscora, Cracosna, Duplipetala, Hoppea, Microrphium, Phyllocyclus and Schinziella is presented, including keys to the taxa, distribution maps and seed coat descriptions. One new genus, one new species and seven new combinations are described. In total seven genera and...

We investigated cladistic relationships among the genera and species of paleotropical Gentianaceae-Canscorinae using morphological characters. Twenty-five characters were scored across all 23 species of the subtribe plus four outgroup species representing the closely related Coutoubeinae and Chironiinae. The maximum parsimony analysis resulted in o...

The phylogenetic relationships of the Canarian laurel forest endemicIxanthus viscosus (Aiton) Griseb. (Gentianaceae) are investigated through a cladistic analysis of sequence variation of parts of the chloroplast genematK and the ITS region of nuclear ribosomal DNA. The floral anatomical and morphological characteristics ofIxanthus based on paraffi...