Published September 5, 2025 | Version v1
Taxonomic treatment Open

Cosmarium quadriverrucosum var. supraornatum Skuja

  • 1. Laboratorio de Zoología y Ecología Acuática-LAZOEA, Universidad de los Andes, Cra. 1 # 18 A- 12, Bogotá 111711 (Colombia)
  • 2. Grupo de Investigación en Biodiversidad, Medio Ambiente, y Salud (BIOMAS), Universidad de Las Américas (UDLA), Vía a Nayón, Quito 170124 (Ecuador)
  • 3. Grupo de Investigación en Biodiversidad, Medio Ambiente, y Salud (BIOMAS), Universidad de Las Américas (UDLA), Vía a Nayón, Quito 170124 (Ecuador) & Global Research & Solutions Center, Colegio de Ciencias Biológicas y Ambientales (COCIBA), Universidad San Francisco de Quito, Diego de Robles S / N y Pampite, Quito 170901 (Ecuador)
  • 4. Grupo de Investigación en Biodiversidad, Medio Ambiente, y Salud (BIOMAS), Universidad de Las Américas (UDLA), Vía a Nayón, Quito 170124 (Ecuador) & Laboratorio de Ecología Acuática, Centro de Ecología, Instituto Venezolano de Investigaciones Científicas (IVIC), Carretera Panamericana Km 11, Caracas 1020 - A (Venezuela)

Description

Cosmarium quadriverrucosum var. supraornatum Skuja **

(Fig. 2M)

Nova Acta Regiae Societatis Scientiarum Upsaliensis, serie 4, 14 (5): 139 (Skuja 1949).

DISTRIBUTION. — Brazil, Myanmar, China, Australia, and New Zealand. Amazon Basin: no records. Western Amazonia (lowlands): no records.

DeScRiPTiON

Cells 5.9 µm long, 25.4 µm wide, isthmus 9.0 µm; cells as long as wide. Cells with deep median constriction, closed median sinus, straight; subcircular semicells; apical margin straight to broadly rounded; central tumor with warts on the face of the semicell, a variable number of warts in rows around the semicell, without any arrangement; axial chloroplast; two pyrenoids.

REMARKS

This taxon is small and is recognized from the type variety by having a more wavy, irregular cell outline which is given by the presence of more warts. Compared with Cosmarium furcatospermum West & G.S.West, C. quadriverrucosum var. supraornatum has two pyrenoids instead of one. Our specimens are morphologically similar and within size range shown for this taxon in the original description by Skuja (1949) and those reported by Oliveira de et al. (2010) for Brazil and Dingley (2001) for Australia.

Notes

Published as part of SÁNCHEZ, Luzmila, SÁNCHEZ, Fernando R., RÍOS-TOUMA, Blanca & José V. MONTOYA, 2025, Desmidiales (Desmidiaceae, Zygnematophyceae) from lowland rivers and floodplain lakes of Ecuadorian Amazonia, pp. 31-60 in Cryptogamie, Algologie 46 (3) on page 40, DOI: 10.5252/cryptogamie-algologie2025v46a3, http://zenodo.org/record/17108984

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Linked records

Additional details

Biodiversity

Scientific name authorship
Skuja
Kingdom
Plantae
Phylum
Charophyta
Order
Zygnematales
Family
Desmidiaceae
Genus
Cosmarium
Species
supraornatum
Taxon rank
variety

References

  • SKUJA H. 1949. - Zur Susswasseralgenflora Burmas. Nova Acta Regiae Societatis Scientiarum Upsaliensis, Serie 4, 14 (5): 1-188.
  • OLIVEIRA DE I. B., BICUDO C. E. M. & MOURA C. W. N. 2010. - Contribuicao ao conhecimento de Cosmarium Corda ex Ralfs (Desmidiaceae, Zygnematophyceae) para a Bahia e o Brasil. Hoehnea 37: 571-600. https://doi.org/10.1590/S2236-89062010000300007
  • DINGLEY M. 2001. - Desmids of New South Wales: new species and new records. Telopea 9 (3): 601-637.