Biodiversity Data Journal :
Taxonomy & Inventories
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Corresponding author: Paterne A. B. Mingou (mingoupaterne@hotmail.fr)
Academic editor: Yasen Mutafchiev
Received: 09 Aug 2024 | Accepted: 28 Nov 2024 | Published: 03 Dec 2024
© 2024 Paterne Mingou, Mathieu Gueye, Theophile Bayet, Christophe Cambier
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Mingou PAB, Gueye M, Bayet T, Cambier C (2024) First records of Selaginella kraussiana and Selaginella subcordata from Senegal (Selaginellaceae). Biodiversity Data Journal 12: e134350. https://doi.org/10.3897/BDJ.12.e134350
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The monogeneric family Selaginellaceae is made up of about 700 species distributed throughout the world, but the most concentrated part is in tropical and subtropical areas. According to the most recent infrageneric classification of the genus Selaginella, six or seven subgenera can be recognised and perhaps 700 species. The genus is monophyletic, cosmopolitan, characterised by the presence of rhizophores, ligulated leaves and has a reniform adaxial sporangia with two type of spores (heterospory).
The records of two species are reported, that is S. kraussiana (Kunze) A.Braun and S. subcordata A.Braun ex Kuhn, which are new for the state of Senegal. Ecological traits, especially related to the habitat and altitude-elevation distribution, are also described for these species. Both species were collected in the south of Senegal, more precisely in the region of Kédougou for S. Kraussiana and in the regions of Kédougou, Tambacounda and Ziguinchor for S. subcordata.
Pteridophytes, Kédougou, Ziguinchor, distribution, ecology, herbaria
Lycophyta is a monophyletic group of plants with microphylls and adaxial reniform sporangia (
In Senegal, there were just a few studies focused on Pteridophytes, i.e.
Several prospecting surveys were carried out in rice fields, palm groves, water ponds, forests and gallery forests, mountains and waterfalls on various administrative regions of Senegal while considering the specificity of environments as well. Fertile samples were collected, pressed and preserved at the IFAN Herbarium, which is the oldest botanical collection in French-speaking Africa. However, when mature individuals were not available, sterile samples were collected. For each sample, duplicates or even more samples were collected, depending on the size of the population encountered. Wanting to facilitate the identification and confirmation of these species, photos of the plant and its organs before and after sampling were joined with the herbarium collections. A fragment of the blade was also taken every time and preserved in silica gel according to the protocol of
At the same time, herbarium specimens of Pteridophytes preserved in the BR, DAKAR, IFAN and P Herbaria were checked (herbaria acronyms according to
Initial species identification in the field was later verified and validated in the laboratory by making a comparison with referenced specimens from DAKAR and IFAN herbaria. IPNI (https://www.ipni.org) allowed us to update the names of the species according to their correct names. At the higher rank (genus and family), we took into account the recent phylogenetic works by
For the description of the species, we used a LEICA M80 binocular stereomicroscope equipped with an IC80 HD type camera connected to a computer. Images taken with the LAS EZ 4 software made it possible to describe and compare the morphology of the specimens with the specimens available in the databases of JSTOR (https://plants.jstor.org/) and African Pteridophytes (https://www.fernsofafrica.com/index.php). Our collections and occurrence data obtained from the Global Biodiversity Information Facility (GBIF; http://www.gbif.org/occurrence/search?taxon) have enabled the production of mapping species distribution in Africa.
A total of 1160 herbarium specimens of Pteridophytes (665 new and 495 old collections), preserved in the IFAN, DAKAR, BR and P herbaria, were consulted, including 43 of the genus Selaginella. As a result, the Senegalese pteridoflora is enriched with two species (Selaginella kraussiana and Selaginella subcordata) that had not been previously reported in the country. They come from our field collections for Selaginella kraussiana and cumulatively from historical collections and our field collections for Selaginella subcordata. For the latter, the old collections are all stocked in BR.
Plant terrestrial (Fig.
Distribution in Senegal: Kédougou Region (Fig.
Distribution in Africa: Algeria, Angola, Burundi, Cameroon, Comoros, Ethiopia, Kenya, Madagascar, Malawi, Mozambique, Uganda, DRC, Rwanda, Sao Tome and Principe, Sudan, South Africa, Tanzania and Zimbabwe (
Selaginella kraussiana is found predominantly as a lithophyte at altitudes between 133 and 391 m a.s.l., on both sides of the Dindefélo Falls cliff, but it is more confined on the south side at almost all levels of the cliff at 100 m, 90 m, 80 m, 60 m, 50 m, 20 m and 10 m high and on the north side at 50 m and 30 m. The souhern part of the cliff is humid and very sunny, with few species of trees, unlike the northern part which is less humid and very sunny. On the Dindefélo cliff, S. kraussiana was found each time under plant cover in association with pteridophyte species such as Aleutopteris farinosa (Forssk.) Fée, Blotiella currorii (Hook.) R.M. Tryon, Dicranopteris linearis (Burm.f.) Underw. and Selaginella versicolor Spring, but also with byophytes and spermatophytes such as Dombeya quinqueseta (Delie) Excell, Mitragyna inermis (Willd.) K.Schum. and Raphia sudanica A.Chev. It forms a green carpet on the rock. It is also found on land on the banks of a river on the Bembou-Massa axis.
Plant lithophytic (Fig.
Distribution in Senegal: Three Regions: Kédougou, Tambacounda and Ziguinchor (Fig.
Distribution in Africa: Cameroon, Ivory Coast, Gabon, Ghana, Guinea, Liberia, Nigeria, Sierra Leone and Sudan (
Selaginella subcordata is found as a lithophyte at altitudes between 116 and 483 m a.s.l., on either side of the Dindefélo Falls cliff, at 100 m, 60 m, 50 m and 1 m on the south side and 90 m, 40 m on the north side. The southern part of the cliff is humid and not very sunny, with a few species of trees, unlike the northern part which is less humid and very sunny. On the Dindefélo cliff, S. subcordata as well as S. kraussiana was found each time under plant cover in association with pteridophyte species such as Aleutopteris farinosa (Forssk.) Fée, Blotiella currorii (Hook.) R.M. Tryon, Dicranopteris linearis (Burm.f.) Underw. and Selaginella versicolor Spring, but also with byophytes and spermatophytes such as Dombeya quinqueseta (Delie) Excell, Mitragyna inermis (Willd.) K.Schum. and Raphia sudanica A.Chev. It was also found on the track going down the Dimboli cliff, but also on rocks not far from the Sédou stream bridge in Ebarack. In Ziguinchor, it was found on a small damp humid area, covered with bushes, along a path. In Tambacounda, the habitat of historical specimens from Niokolo-Koba Park, has not been mentioned.
Selaginella subcordata was first collected in April 1951 by Berhaut J (BR0000020401276), then on 25 October 1990 by Vanden Berghen C. (BR0000015471284) and recently by Mingou et al. 2019, 2020 (See Senegalese materials examined above) and is reported for the first time for Senegal.
Identification keys to the Selaginella species in Senegal |
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1 | Stems twining, glabrous, straw-coloured, with distant leaves | Selaginella myosurus |
– | Stems erect, arched or prostrate, never twining | 2 |
2 | Sporophylls uniform; lateral leaves serrate with two false veins, lower surface of the leaf light green, upper surface dark green | Selaginella versicolor |
– | Sporophylls dimorphic | 3 |
3 | Rhizophores on the upper surface of the stems, along its entire length; delicate leaves | Selaginella kraussiana |
– | Rhizophores in lower half of stem | 4 |
4 | Lateral leaves with a subcordate upper base, covering the main stem | Selaginella subcordata |
– | Lateral leaves with rounded upper base, not covering the main stem, the lower base is more or less developed | Selaginella tenerrima |
For the identification of Selaginellaceae species from Senegal, certain characters were essential such as the types of rhizome, sporophyll as well as the arrangement of the rhizophores. Therefore, these interspecific morphological differences in Selaginella are often indistinct or unclear and the group is known for problems with species identification (
Pteridophytes inhabit a wide variety of substrates, climates and light regimes (
Selaginella kraussiana and Selaginella subcordata have been reported in other parts of the world, but they do not have the same geographical distribution in African or even at global level. Selaginella kraussiana is a subcosmopolitan species with distribution in Africa, Asia, America and Europe (
The authors thank the different herbariums which made samples accessible via the RECOLNAT research infrastructure for P as well as that of BR. We also thank the curator of the DAKAR Herbarium.