Spore morphology of Selaginella borealis, S. sanguinolenta and S. helvetica (Selaginellaceae, Lycopodiophyta)

Abstract

For the first time we have conducted a study of three species of the genus Selaginella P. Beauv. from Russia: S. sanguinolenta (L.) Spring, S. helvetica (L.) Link and S. borealis (Kaulf.) Rupr. using the method of scanning electron microscopy (SEM). In a comparative analysis of the morphology of micro- and megaspores of S. sanguinolenta, S. helvetica and S. borealis, we first compiled an information on representatives of Selaginella from the territories of China and Russia. A distinctive feature of S. borealis and S. sanguinolenta based on the megaspore morphology is the different nature of the exosporium surface: S. borealis has the exosporium with rounded-polygonal tubercles, and S. sanguinolenta has the exosporium with roller-like folds rising above the sporoderma. S. sanguinolenta is characterized by following species-specific features of microspores: the presence of radially arranged convolutions on the proximal surface of the spore, outside the laesura, and convoluted folds on the distal surface of the microspores. S. helvetica is characterized by the following microspore morphology: the hemispherical distal side is in the equatorial position, and flat proximal side; the surface of the exosporium is granular, completely covered with rounded-polygonal tubercles. In the research we confirmed the presence of S. borealis in China (Yunnan). It has been established that the morphology of S. sanguinolenta microspores from the Khabarovsk Territory, the Republics of Buryatia, Tuva and the Irkutsk Region is identical to the microspores of representatives of S. sanguinolenta from China (Yunnan); and the morphology of S. helvetica microspores from the territory of the Chita Region, Trans-Baikal and Primorye Territories is identical to the morphology of the species samples from Liaoning Province (China).

Keywords

• lycopodiophyta
• microspores
• megaspores
• russia
• scanning electronic microscopy (sem)
• selaginella
• selaginella borealis
• selaginella sanguinolenta
• selaginella helvetica
• selaginellaceae
• siberia
• spore morphology