A comparative study of spores of two species of Vaginularia (Vittarioideae, Pteridaceae) from South-Eastern -Vaginularia paradoxa (Fée) Mett. ex Miq. and V. trichoidea Fée -was performed by the method of scanning electronic microscopy (SEM).Spores are tetrahedral, trilete; they are very similar to each other in smooth surface and relatively narrow laesura arms. Differences between species are in shape of spores in proximal position (triangular with narrowly-rounded corners and concave sides in V. paradoxa and triangular with broadly-rounded corners and slightly concave sides in V. trichoidea), in length of laesura arms relative to the radius of the spore (laesura arms are about 0.75 of spore radius in V. paradoxa, and riches corners of spore in V. trichoidea) and in size of spore (spore of V. paradoxa are about 1.5 times more in equatorial diameter and 1.7 times more in polar axis length). Some time ago, SEM-method was used to make a detailed analysis of the spore morphology of Vaginularia species on samples from New Guinea (Monogramma (Vaginularia) emarginata (Brause) K.I. Goebel) and Fiji (V. angustissimus (Brack.) Mett.) (Tryon, Lugardon, 1991). They described spore as tetrahedral-globose in shape, with trilete aperture, the laesura arm length from ½ to ¾ of the radius of spore, surface of spore is plain. The micrographs of the spores of Vaginularia junghuhnii Mett. and V. trichoidea (J. Sm.) Fée are given by Ch.-W. Chen et al. (2017). Spores of the both species are tetrahedral-globose, with smooth surface. Spores of V. trichoidea was studied by Yi-H. Chang et al. (2015). It was shoved on numerous example that spore morphology and molecular-phylogenetic results are congruent for different genera such as Gymnocarpium and Cystopteris (Gureyeva, Kuznetsov, 2015), Onichium (Vaganov et al., 2017 a, b, c), Pityrogramma (Vaganov et al., 2017b therefore the morphology of spores has phylogenetic signification. Spore morphology is very important for systematics of Pteridaceae subfamilies: Cryptogrammoideae (Vaganov, 2016) and Ceratopteridoideae (Vaganov et al., 2017c).The aim of this study is to provide details of spore morphology of two Vaginularia species -V. paradoxa (Fée) Mett. ex Miq. and V. trichoidea (J. Sm.) Fée -from South-Eastern Asia using scanning electronic microscopy (SEM) to reveal features useful for systematics and phylogenetics.
Materials and methodsSpores were obtained from herbarium specimens of two species: Vaginularia paradoxa (Java Island, Indian Ocean Islands southwards of India) and V. trichoidea (Hainan Island) stored in PE