Stenochlaena

Abstract: The fern family Blechnaceae is cosmopolitan; however, the vast majority of species are placed in Blechnum, which occurs predominantly in the Southern Hemisphere. There are two areas that are particularly species–rich: the south–west Pacific (including Australasia), and Central and South America. Using chloroplast DNA sequences, we report the first comprehensive phylogenetic analysis of the Blechnaceae, including all genera widely recognised in recent treatments, and over half of the species. There is strong support for several major clades, which we characterise morphologically and geographically, and some of their interrelationships. Blechnum is confirmed as polyphyletic. Blechnum indicum and B. serrulatum are more closely related to Salpichlaena and Stenochlaena, and are segregated as a new genus, Telmatoblechnum. Alternative generic circumscriptions are discussed for the remainder of Blechnum. In the absence of morphological characters to diagnose the clades within core Blechnum, and for the sake of taxonomic stability, we advocate a broad circumscription for Blechnum. Brainea and Sadleria are retained as their relationships are not well resolved, but Doodia and Pteridoblechnum are clearly nested within the core of Blechnum and we provide four new names in Blechnum. Additionally, given the focus of our sampling, we discuss the biogeography of the south–west Pacific, where immigration has been more important in community assembly than what might be superficially inferred from patterns of endemism (with ca. 60% of species endemic to individual land areas).

Abstract: Stenochlaena riauensis , a new fern species from Riau, Indonesia is described and illustrated. This species can be distinguished from its most closely related species S. palustris by the position of fertile and sterile pinnae. In the new species, both fertile and sterile pinnae are located on the same frond, the lower part of lamina consisted of sterile pinnae that gradually narrower towards apex forming linear fertile pinnae. Bangladesh J. Plant Taxon. 22 (2): 137-141, 2015 (December)

Abstract: Introduction: Stenochlaena palustris (Burm.f.) Bedd. is an edible fern from Blechnaceae family, native to India through Southeast Asia to Polynesia and Australia. The study was conducted to evaluate the cytotoxic effect and antioxidant activity of fractions obtained from Stenochlaena palustris leaf extracts. Methods: Stenochlaena palustris (Burm.f.) Bedd. was tested for its antioxidant activity using DPPH assay and in vitro cytotoxic effect against HeLa cancer cell line using MTT assay. Major fractions were obtained from ethanol and ethyl acetate leaves extract of Stenochlaena palustris (Burm.f.) Bedd. through gravity column chromatography and the secondary metabolites were screened using qualitative phytochemical analysis. Results: In DPPH assay, the highest radical scavenging activity was exhibited by fraction 11 of ethanol extract and fraction 4 of ethyl acetate extract at 98.47±0.002% (ED50=0.120 mg/mL), and 81.38±0.018% (ED50=0.650 mg/mL), respectively. Meanwhile, ascorbic acid and kaempferol exhibited radical scavenging of 80.95±0.002% (ED50=0.014 mg/mL) and 98.67±0.006% (ED50=0.011 mg/mL). As for MTT assay, the percentages of cell viability of both cell lines decreased as the concentration increased. Fraction 7 of ethanol extract and fraction 1 of ethyl acetate extract exhibited the lowest IC50 value of 4.58 μg/mL and 8.60 μg/ml, respectively. Doxorubicin hydrochloride showed lowest IC50 value of 2.21 μg/mL against HeLa cells. Conclusion: The fractions isolated from ethanol and ethyl acetate leaves extract of Stenochlaena palustris (Burm.f.) Bedd. exhibited higher cytotoxic effect against HeLa cells, and higher radical scavenging activity.