Haplozyga armata (Nordstedt) Raciborski var. armata

Araújo, Camila Barbosa de, Bicudo, Carlos Eduardo de Mattos, Takiyama, Luís Roberto & Melo, Sérgio de, 2020, Pseudofilamentous desmids (Zygnematophyceae) from an Amazonian floodplain lake (Macapá, AP, Brazil), Iheringia, Série Botânica (e 2020010) 75, pp. 1-14 : 7

Haplozyga armata (Nordstedt) Raciborski var. armata , Flora, Jena 81: 32, pl. 3-4, fig. 6. 1895.

Basionym: Gymnozyga armata Nordstedt , Acta Universitatis lundensis 3: 1, pl. 1, fig. 1-3. 1889.

( Fig. 15 )

Cells 2 times greater in length than width, 27-42 × 14-21 μm, 6-10 μm broad at the apex and 14-15 μm broad at the isthmus. Semicells hexagonal; straight to slightly convex lateral margin; apex straight; 1 intumescence ornamented with a ring of robust spines and a small divergent indentation at the base; moderate median constriction; open to acute median sinus; smooth cell wall.

Material examined: BRAZIL, AMAPÁ, Macapá, Curralinho Lake , 02.VI.2007, C.B. Araújo (SP469217), 12.II.2008, C.B. Araújo (SP469224), 15.IV.2008, C.B. Araújo (SP469226), 13.V.2008, C.B. Araújo (SP469227), 15.VII.2008, C.B. Araújo (SP469228) .

Comments: Haplozyga (Nordstedt) Raciborski is a typically tropical genus and includes only two species and one taxonomical variety: Haplozyga armata var. armata (Nordstedt) Raciborski , Haplozyga armata var. raciborskii Förster and Haplozyga eckertii Förster. The species H. armata var. armata was originally described as Bambusina (Gymnozyga) armata Nordstedt by Nordstedt (1889). However, according to Bicudo & Menezes (2017), it was reclassified, in 1985, as Gymnozyga section: Haplozyga . Considering that specimens of Haplozyga are morphologically very distinct from those of Bambusina and of all other desmids genera, it worth maintaining it as a distinct genus until other polyphasic studies using molecular and phylogenetic analyses can confirm its taxonomic classification.

Distribution in Brazil: Goiás (Förster 1966); São Paulo (Förster 1966).

Figures

Figs. 3-15. Pseudofilamentous desmids of Curralinho Lake, Macapá, Amapá, Brazil. 3 A-C. Bambusina borreri. A, B. detailed cells; C. detailed pseudofilament; 4. B. borreri var. brasiliensis; 5 A-B. B. borreri var. majus, detailed cells and pseudofilaments; 6. Desmidium baileyi var. baileyi f. bailey; 7 A-B. D. elegans. A. detailed pseudofilament, B. detailed cell; 8 A-B. D. graciliceps var. graciliceps. A. frontal view of the pseudofilament, B. slight modification of the pseudofilament frontal view; 9. D. graciliceps var. groenbladii; 10 A-C. D. longatum. A. pseudofilament frontal view, B. formation of the elongate conjugation tube, C. zygospore; 11 A-B. D. quadratum var. quadratum. A. detailed pseudofilament, B. detailed cells; 12. D. quadratum var. constrictum; 13 A-B. Groenbladia neglecta var. neglecta. A. detailed pseudofilament, B. detailed cells; 14 A-B. G. neglecta var. elongata. A. detailed pseudofilament, B. detailed cells; 15. Haplozyga armata var. armata. Scale bars = 10 µm.