Pleurotaenium subcoronulatum var. africanum (Schmidle) Willi Krieger 1937: 423

Levanets, Anatoliy & Vuuren, Sanet Janse Van, 2024, New insights into the morphology, taxonomy and geographical distribution of Pleurotaenium subcoronulatum (Zygnematophyceae, Desmidiales), Phytotaxa 655 (2), pp. 144-158 : 151

5. Pleurotaenium subcoronulatum var. africanum (Schmidle) Willi Krieger 1937: 423 , pl. 46: fig. 8

Basionym: Pleurotaenium cristatum f. africanum Schmidle 1902: 66 , pl. I [1]: fig. 17 (as “ africana ”)

Type locality: Nyassa Lake, from a quiet bay of the Mbasi River, covered with water nuts, near its confluence with the Nyassa, April 27, 1899 [now Tanzania].

Description: The cell dimensions are slightly smaller compared to the type and the cells are attached in chains ( Fig 4D ). Cells are 400 µm in length, with both the apices and the basal swelling 24 µm wide. The rest of the semicell is 20 µm wide ( Schmidle 1902). The cell wall is punctated to granulated. The margins of the cell wall are parallel, narrowing towards the crown of tubercles.

Distribution:

North America: USA ( Prescott et al. 1975; Dillard 1990).

South America: Venezuela ( Salazar & Guarrera 2000).

Africa: Côte d’Ivoire ( Bourrelly 1961), Democratic Republic of Congo ( Van Oye 1953), Guinea-Bissau ( Rino 1969), Mozambique ( Rino 1971), Nigeria ( Opute 2000; Kadiri 2002; Ekhator et al. 2013, 2014; Ekhator & Alika 2016); South Sudan ( Grönblad et al. 1958), Sudan ( Smith 2015), Tanzania ( Schmidle 1902), Uganda ( Grönblad et al. 1964). Lakes on borders of African countries: Lake Nyasa/ Malawi ( Cocquyt et al. 1993).

Asia: Bangladesh ( Ahmed et al. 2008), India ( Tessy & Sreekumar 2011; Gupta 2012; Boruah & Baruah 2024), Japan ( Hirano 1956; Kanetsuna 1967; Hirose et al. 1977).

Australia and New Zealand: Australia (as Pleurotaeniopsis subcoronulata var. africana (Schmidle) Willi Krieger ) ( Day et al. 1995).

Figures

FIGURE 4. Comparison of the morphology of P. subcoronulatum with closely related infraspecific taxa. A) P. subcoronulatum (from Turner 1893), B) P. subcoronulatum (from West & West 1895, C) P. subcoronulatum f. elongatum (from Prescott et al. 1975), D) P. subcoronulatum var. africanum (from Krieger 1937), E) P. subcoronulatum var. detum (from West & West 1896), F) P. subcoronulatum var. maximum (from Van Oye 1953), G) P. subcoronulatum var. rectum (from Borge 1903) and H) P. subcoronulatum var. spinulosum (from Opute 2000). No scale bars; dimensions indicated in descriptions.