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This paper continues consideration of the spores of three paleotropical fern genera – Taenitis, Syngramma, and Austrogramme (Pteridoideae, Pteridaceae) from South-Eastern Asia and Oceania. At the second stage, we carried out a comparative scanning electron microscopy study of spores of three species of Austrogramme, four species of Syngramma, and six species of Taenitis and added information about previously studied spores of seven species of these genera. Spores of all examined species are trilete, tetrahedral or tetrahedral-globose with convex to hemispherical distal side and plane, convex or conical proximal side. The spores of Austrogramme species are the smallest, simplest in ornamentation and similar to each other. Sculpture of the proximal and distal sides are microverrucate, the surface of the spores is covered by granular deposits. Spores of most Syngrammaspecies are very similar to spores of Austrogramme species in shape and surface sculpture: their distal and proximal surfaces are microverrucate, whereas the spores of S. borneensis and S. cartilagidens have the low-tuberculate sculpture. Spores of Taenitis species are very different from the spores of Austrogramme and Syngramma. Seven of nine studied species have spores with well-expressed cingulum (T. blechnoides, T. cordata, T. diversifolia, T. interrupta, T. luzonica, T. obtusa, and T. requiniana), three species (T. cordata, T. hookeri, and T. pinnata) have spores with prominent laesural ridges. The spores have well-expressed ornamentation – tuberculate, baculate, rugate, tuberculate-rugate. The most conspicuous character of the ornamentation of spore surfaces is the presence of rodlets associated with sculpture elements. The densest rodlets are characteristic of Taenitis diversifolia, T. luzonica, T. obtusa, and T. requiniana. Spore size (equatorial diameter) ranges on average between 22 μm and 37 μm in Austrogramme, between 27 μm and 41 μm in Syngramma, and between 26 and 51 μm in Taenitis species.

This research is the first comprehensive analysis of the intrageneric relationships of Actiniopteris and Onychium based on original data including spore morphology, phylogeny and phylogeography. Actiniopteris and Onychium are members of the large subfamily Pteridoideae of the family Pteridaceae. The Pteridaceae family is considered one of the most taxonomically confusing families due to its representatives high level of polymorphism.         We used an interdisciplinary approach to study the “Onychium clade”: 13 taxa were studied using scanning electron microscopy (SEM) to characterize the morphology and morphometry of spores; 14 taxa were studied from a phylogenetic perspective, including character evolution and ancestral character state reconstructions; 15 taxa of “Onychium clade” were studied using herbarium data (B, P, PE, LE, VLA, TI, KYO, ALTB and TK) according to global botanical and geographical zones.                As a result of this integrated analysis, we established a deep divergence of the taxa O. tenuifrons and O. siliculosum from the main composition of the genus Onychium and the division the genus Actiniopteris into two clades: A. radiata–A. semiflabellata and A. australis–A. dimorpha. We found that representatives of Actiniopteris and Onychium had originated in a common African-Indo-Malesian area. The “Onychium clade” center of diversity is the Indian Region, which is experiencing high levels of human impact, leading to disjunctions among the studied taxa.

Using the method of scanning electronic microscopy (SEM), a comparative study of twelve representatives of subfamily Cryptogrammoideae S.Linds. family Pteridaceae E.D.M.Kirchn. was carried out. A comparative study of morphological characters of investigated spores has revealed characters that allow considering the relatedness of the studied species to one subfamilyCryptogrammoideae. These characters include: spore form is roundish-triangular, lociniate in proximal-polar and distal-polar positions; spore contour is low-crenate to smooth; distal side of the spore in an equatorial position is convex; rays of laesura are straight, raised over a sporoderm surface; exosporium is clearly defined from fine-granulate to verrucate. Vaganov, A.V. (2016). A comparative study of spore morphology of the subfamily Cryptogrammoideae genera. Biological Citation: