Otto Warburg (1859–1938) had a great interest in tropical botany. He travelled in South-East Asia and the South Pacific between 1885 and 1889 and brought back a considerable collection of plant specimens from this expedition later donated to the Royal Botanical Museum in Berlin. Warburg published the first comprehensive monograph on the family Pandanaceae in 1900 in the third issue of Das Pflanzenreich established and edited by Adolf Engler (1844–1930). The aim of this article is to clarify the taxonomy, nomenclature and typification of Warburg's contributions to the Pandanaceae. Considerable parts of Warburg's original material was destroyed in Berlin during World War II but duplicates survived, shared by Engler and Warburg with Ugolino Martelli (1860–1934). Martelli was an expert on the family and he assembled a precious herbarium of Pandanaceae that was later donated to the Museo di Storia Naturale dell'Università degli Studi di Firenze. Warburg published 86 new names in Pandanaceae between 1898 and 1909 (five new sections, 69 new species, five new varieties, two new combinations and five replacement names). A complete review of the material extant in B and FI led to the conclusion that 38 names needed a nomenclatural act: 34 lectotypes, three neotypes and one epitype are designated here. Twenty new synonyms are also proposed. One Freycinetia name and six Pandanus names are considered as incertae sedis. A total of 21 names published by Warburg are accepted: 11 in Freycinetia and ten in Pandanus. In addition, four names published in Pandanus by Warburg serve as the basionyms of accepted names in the genus Benstonea.

Citation: Callmander M. W., Vogt R., Donatelli A., Buerki S. & Nepi C. 2021: Otto Warburg and his contributions to the screw pine family (Pandanaceae). – Willdenowia 51: 5–31.

Version of record first published online on 15 February 2021 ahead of inclusion in April 2021 issue.

Van de Vijver B., Tudesque L. & Ector L. (ed.), Diatom taxonomy and ecology. From France to the sub-Antarctic islands. Celebrating the work and life of Prof. Dr. René Le Cohu on the occasion of his 80^th birthday. – Nova Hedwigia Beiheft 146. – Stuttgart: J. Cramer in Borntraeger Science Publishers, 2017. – ISBN 978-3-443-51068-8. – 17 × 24 cm, 780 g, 325 pp., 1210 figures, 24 tables, softback. – Price: EUR 139.00. – Available at  https://www.schweizerbart.de/papers/nova_suppl/list/146#issue

Citation: Mora D. 2021: Book review: Van de Vijver B., Tudesque L. & Ector L. (ed.), Diatom taxonomy and ecology. From France to the sub-Antarctic islands. Celebrating the work and life of Prof. Dr. René Le Cohu on the occasion of his 80^th birthday. – Willdenowia 51: 33–34.

Version of record first published online on 15 February 2021 ahead of inclusion in April 2021 issue.

Sticta is a subcosmopolitan genus most diverse in the tropics. Traditionally, many taxa were considered to be widespread and morphologically variable, following broadly circumscribed morphodemes. Among these is the S. weigelii morphodeme, characterized by a cyanobacterial photobiont and rather narrow, flabellate to truncate or tapering lobes producing predominantly marginal isidia. Molecular phylogenetic analyses focusing on the ITS fungal barcoding marker revealed that this morphodeme represents several species, some of which are only distantly related to each other. Here we describe two species and one subspecies of this morphodeme as new to science, based on analysis of 400 specimens, for 344 of which we generated ITS barcoding data. The two new species, S. andina and S. scabrosa, are broadly distributed in the Neotropics and also found in Hawaii, where the latter is represented by the new subspecies, S. scabrosa subsp. hawaiiensis; in the case of S. andina, the species is also found in the Azores. Sticta andina exhibits high phenotypic variation and reticulate genetic diversification, whereas the phenotypically rather uniform S. scabrosa contains two main haplotypes, one restricted to Hawaii. Sticta andina occurs in well-preserved montane to andine forests and paramos, whereas the two subspecies of S. scabrosa are found in tropical lowland to lower montane forests, tolerating disturbance and extending into anthropogenic habitats.

Citation: Moncada B., Mercado-Díaz J. A., Smith C. W., Bungartz F., Sérusiaux E., Lumbsch H. T. & Lücking R. 2021: Two new common, previously unrecognized species in the Sticta weigelii morphodeme (Ascomycota: Peltigeraceae). – Willdenowia 51: 35–45.

Version of record first published online on 24 February 2021 ahead of inclusion in April 2021 issue.

The genus Cailliella includes a single species, C. praerupticola, restricted to a sandstone plateau region in Coyah, Dubreka, Forécariah and Kindia Préfectures, Guinea, West Africa. Until its rediscovery in 2016, this species was known only by the type gathering made in 1937. We provide an emended description, photographs of living material, locality and habitat data, and a discussion of its conservation status. We further designate a lectotype for C. praerupticola. On the basis of morphology, Cailliella had been considered an isolated member of the tribe Melastomateae, possibly sister to Melastomastrum. We tested the classification of Cailliella by means of a phylogenetic analysis of C. praerupticola and 40 other samples of African Melastomateae, based on molecular sequence data from the external and internal transcribed spacer regions of nuclear ribosomal DNA (nrETS and nrITS) as well as the ndhF, psbK-psbL and accD-psaI regions of chloroplast DNA. Our results corroborate the placement of Cailliella in the Melastomateae, where it was resolved as sister to a clade consisting of both Melastomastrum and Tristemma. The hypothesis of C. praerupticola being an evolutionary relict or “palaeoendemic” is supported by our findings.

Citation: Veranso-Libalah M. C., Stone R. D., Haba P. M., Magassouba S., Kadereit G. & Burgt X. M. van der 2021: Phylogenetic placement of Cailliella praerupticola (Melastomataceae), a rare, monospecific lineage from Guinea, West Africa. – Willdenowia 51: 47–56.

Version of record first published online on 9 March 2021 ahead of inclusion in April 2021 issue.

The species of Anthracoidea on Carex are host-specific smut fungi restricted to sedges belonging to the same or closely related sections. They are characterized by sori that form black, hard bodies around aborted nuts of their hosts. In Carex sect. Hallerianae, only one species, C. halleriana, is known as a host of Anthracoidea. The taxonomic status of this smut fungus was problematic due to a lack of molecular data. It has been reported under different names, mainly as “A. caricis” or “A. irregularis”. A comparative morphological study and molecular phylogenetic analysis, using LSU (large subunit) nuclear rDNA sequences, supported the recognition of a distinct species, A. hallerianae. The new species is described and illustrated based on material from Central Europe, the Iberian Peninsula, the Balkan Peninsula, the Mediterranean area and Transcaucasia.

Citation: Denchev T. T., Denchev C. M., Koopman J., Begerow D. & Kemler M. 2021: Host specialization and molecular evidence support a distinct species of smut fungus, Anthracoidea hallerianae (Anthracoideaceae), on Carex halleriana (Cyperaceae). – Willdenowia 51: 57–67.

Version of record first published online on 9 March 2021 ahead of inclusion in April 2021 issue.

Artabotrys R. Br. is one of the larger genera of Annonaceae with over 100 species distributed throughout the palaeotropics plus northern Australia. Although the genus is morphologically very well circumscribed, species delimitation is quite problematic owing to overlapping morphological characteristics. In Thailand, 20 species of Artabotrys have been reported, including A. multiflorus C. E. C. Fisch. Detailed comparisons with the type specimen from Myanmar revealed that A. multiflorus occurring in Kanchanaburi Province of Thailand represents a new species herein described as A. angustipetalus Photikwan & Chaowasku. The new species differs from A. multiflorus by having fewer flowers per hook, linear (vs oblong to oblong-lanceolate) petals, acute (vs obtuse) petal apex, longer and narrower petals and fewer carpels per flower. A multi-locus plastid phylogeny including an accession of A. angustipetalus and 30 accessions of other species of Artabotrys has been reconstructed. The results uncover a well-supported clade consisting of thorn-bearing species of Artabotrys, with A. angustipetalus recovered outside this clade. To understand the evolution of thorns in Artabotrys, ancestral character-state reconstructions were carried out; this trait is inferred to have evolved only once in Artabotrys. The benefits of thorns in Artabotrys species are discussed and hypothesized.

Citation: Photikwan E., Damthongdee A., Jongsook H. & Chaowasku T. 2021: Artabotrys angustipetalus (Annonaceae), a new species from Thailand, including a plastid phylogeny and character evolutionary analyses of thorn occurrence in Artabotrys. – Willdenowia 51: 69–82.

Version of record first published online on 23 March 2021 ahead of inclusion in April 2021 issue.

We describe the new lichenized fungus Lasioloma antillarum Lücking, Högnabba & Sipman from the Netherlands Antilles. The new species is characterized by a corticolous growth habit, apothecia with shortly tomentose margins, and rather small (35–50 × 12–16 µm), muriform ascospores in numbers of 2(–4) per ascus. The material had originally been identified as Calopadia phyllogena (Müll. Arg.) Vězda, with associated sequence data, but in phylogenetic analyses consistently fell outside the latter genus. Its revised identification as a species of Lasioloma is consistent with its phylogenetic position and underlines the necessity of posterior annotations in public sequence repositories, in order to correct previous identifications.

Citation: Lücking R., Högnabba F. & Sipman H. J. M. 2021: Lasioloma antillarum (Ascomycota: Pilocarpaceae), a new lichenized fungus from the Antilles, and the importance of posterior annotations of sequence data in public repositories. – Willdenowia 51: 83–89.

Version of record first published online on 23 March 2021 ahead of inclusion in April 2021 issue.

Although Melocactus is the second-most diverse cactus genus in Cuba, there is still no consensus regarding species circumscription. Seed morphology has not been used for classifying species in this group in Cuba, despite the taxonomically useful data obtained in some other genera of Cactaceae. In this study, seeds were evaluated for all Melocactus taxa known from Cuba, and seed morphological variability was analysed. Seed descriptions for each studied taxon (or localities) are presented here. We analysed 10 quantitative, and 19 qualitative characters in 50 seeds of 14 accessions. Seeds of the native species of Melocactus of Cuba are small to medium-sized, which place them among the smaller in the Cactoideae, and their shape is circular to broadly oval. Our results show that seven quantitative and six qualitative characters evaluated were suitable to distinguish among taxa. Such characters allowed establishing a general seed pattern for the M. matanzanus and M. curvispinus group, however, seeds in the M. harlowii group were less distinguishable using these characters. Colliculate relief characterized seeds of the M. matanzanus group with the testa border not expanded, while the M. curvispinus group seeds were identified by their ventro-apical keel. The most useful characters for species delimitation in the M. curvispinus group were seed length, and hilum-micropylar region characters. Significant characters that reveal differences within the M. harlowii group are lustre, seed relief and testa border expansion.

Citation: Lemus-Barrios H., Barrios D., García-Beltrán J. A., Arias S. & Majure L. C. 2021: Taxonomic implications of seed morphology in Melocactus (Cactaceae) from Cuba. – Willdenowia 51: 91–113.

Version of record first published online on 5 April 2021 ahead of inclusion in April 2021 issue.

Garden escapes of Acer campestre spread as a cryptic invading gene pools and challenge the conservation of a unique ancient population in southern Scandinavia. The native gene pool consists of just 34 individuals and is listed as critically endangered. This population is more than 150 years old and represents a unique diorama into an almost extinct genetic diversity of the early 19^th century. That the native individuals cannot be separated from the introduced by morphology makes it impossible to delimit populations worthy of conservation. Genetic structuring was based on six SSR markers and reveals that, although the native population is small, it does not suffer from inbreeding. This article reports a high group affinity (Q coefficient) of the known native gene pool and a new finding of a population not earlier identified as native. Because the population is old and the fruit set is strongly reduced, it is recommended to preserve the genetic material by ex situ grafting and introduction of carefully chosen individuals from related gene pools.

Citation: Wahlsteen E. 2021: SSR markers distinguish critically endangered Acer campestre populations from cryptic invading gene pools. – Willdenowia 51: 115–125.

Version of record first published online on 5 April 2021 ahead of inclusion in April 2021 issue.

Stache-Weiske A. & Meier-Barthel F. (ed.), Georg Rosen. Notizen von einer Reise durch Serbien, Anatolien und Transkaukasien in den Jahren 1843 und 1844. – Berlin: EB-Verlag, 2020 (= Conermann S. (ed.), Bonner Islamstudien 44). – ISBN 978-3-86893-348-2. – 15.5 × 22.5 cm, 570 pp., eight illustrations, hardback. – Price: EUR 34.80. – Available at https://www.ebv-berlin.de/

Citation: Lack H. W. 2021: Book review: Stache-Weiske A. & Meier-Barthel F. (ed.), Georg Rosen. Notizen von einer Reise durch Serbien, Anatolien und Transkaukasien in den Jahren 1843 und 1844. – Willdenowia 51: 127–128.

Version of record first published online on 21 April 2021 ahead of inclusion in April 2021 issue.

Phylogenetic analysis has revealed that Argyranthemum broussonetii is polyphyletic, with subsp. broussonetii (Tenerife) and subsp. gomerensis (La Gomera) resolved in separate clades within the Macaronesian endemic genus Argyranthemum. We show that A. broussonetii subsp. broussonetii and subsp. gomerensis are similar in leaf traits, likely a consequence of adaptation to similar habitats, but that the two can readily be distinguished based on capitula and cypselae characteristics. Indeed, A. broussonetii subsp. gomerensis was found to share greater affinity with A. callichrysum, also from La Gomera based on capitula and cypselae characters, in agreement with its phylogenetic placement. Therefore, we propose that A. broussonetii subsp. gomerensis should be recognized as a subspecies of A. callichrysum, specifically A. callichrysum subsp. gomerensis. A key to differentiate A. broussonetii, A. callichrysum subsp. callichrysum and subsp. gomerensis is provided.

Citation: White O. W., Reyes-Betancort J. A., Chapman M. A. & Carine M. A. 2021: Recircumscription of the Canary Island endemics Argyranthemum broussonetii and A. callichrysum (Asteraceae: Anthemideae) based on evolutionary relationships and morphology. – Willdenowia 51: 129–139.

Version of record first published online on 29 April 2021 ahead of inclusion in April 2021 issue.

This is the thirteenth of a series of miscellaneous contributions, by various authors, where hitherto unpublished data relevant to both the Med-Checklist and the Euro+Med (or Sisyphus) projects are presented. This instalment deals with the families Amaryllidaceae (incl. Alliaceae), Apocynaceae, Caryophyllaceae, Chenopodiaceae, Compositae, Crassulaceae, Cucurbitaceae, Gramineae, Hydrocharitaceae, Iridaceae, Labiatae, Liliaceae, Malvaceae, Meliaceae, Myrtaceae, Orobanchaceae, Oxalidaceae, Papaveraceae, Pittosporaceae, Primulaceae (incl. Myrsinaceae), Ranunculaceae, Rhamnaceae, Rubiaceae, Solanaceae and Umbelliferae. It includes new country and area records and taxonomic and distributional considerations for taxa in Allium, Anthemis, Atriplex, Centaurea, Chasmanthe, Chenopodium, Delphinium, Digitaria, Elodea, Erigeron, Eucalyptus, Hypecoum, Leptorhabdos, Luffa, Malvaviscus, Melia, Melica, Momordica, Nerium, Oxalis, Pastinaca, Phelipanche, Physalis, Pittosporum, Salvia, Scorzoneroides, Sedum, Sesleria, Silene, Spartina, Stipa, Tulipa and Ziziphus, new combinations in Cyanus, Lysimachia, Rhaponticoides and Thliphthisa, and the reassessment of a replacement name in Sempervivum.

Citation

For the whole article:

Raab-Straube E. von & Raus Th. (ed.) 2021: Euro+Med-Checklist Notulae, 13 [Notulae ad floram euro-mediterraneam pertinentes No. 42]. – Willdenowia 51: 141–168.

For a single contribution (example):

Kunev G. 2021: Allium melanogyne Greuter. – Pp. 142–143 in: Raab-Straube E. von & Raus Th. (ed.), Euro+Med-Checklist Notulae, 13 [Notulae ad floram euro-mediterraneam pertinentes No. 42]. – Willdenowia 51: 141–168.

Version of record first published online on 30 April 2021 ahead of inclusion in April 2021 issue.