Zygnema C.A. Agardh

Hilgert-Moreira, Suzane Both & Lorscheitter, Maria Luisa, 2025, Identification of palynomorphs sampled from a sedimentary profile of the last 5000 years in Lagoa dos Patos, Rio Grande do Sul, southern Brazil., Acta Botanica Brasilica (e 20240187) 39, pp. 1-15 : 7

14. Zygnema C.A. Agardh

(Fig. 4H)

Zygospore approximately elliptical, hyaline, cell wall showing circular recesses across the surface. Long axis ca. 43–50 µm (x 48 µm), short axis ca. 30–35 µm (x 33 µm). Ecological data: Zygnema is found in small, shallow freshwater mesotrophic lakes that warm rapidly in spring ( Van Geel, 1978; Bold et al., 1987). Better development observed at temperatures between 15 ºC–20 ºC ( Van Geel & Van der Hammen,1978). Cosmopolitan distribution ( Bicudo & Menezes, 2006).