449 research outputs found
Recent Developments to Improve the Numerical Accuracy
No full textGreen Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Numerical Analysi
Leptochilus oblongus (Polypodiaceae), a new fern species from northern Vietnam
No full textA new fern species, Leptochilus oblongus of Polypodiaceae is described and illustrated from Hoa Binh Province, northern Vietnam. Leptochilus oblongus is most similar to L. ellipticus, but the sori of the former are oblong, close to the lobe margins, and parallel with costule. In contrast, those of the latter are linear, located on main lateral veins, and forming a ca. 45 degree angle with costule
Polystichum duyunense (subg. Haplopolystichum; Dryopteridaceae), a new cave fern from Guizhou, China
No full textA new cave fern of Polystichum (subg. Haplopolystichum; Dryopteridaceae), P. duyunense, is described from a limestone cave in southern Guizhou, China. Polystichum duyunense is most similar to P. cavernicola in having oblong pinnae, but the former has pinnae larger, often angled basiscopically, and somewhat imbricate, while the latter has pinnae smaller, angled acroscopically, and apart from each other
Polystichum loratum (Dryopteridaceae), a New Fern Species from Guizhou, China
No full textA new fern species, Polystichum loratum H. He & Li Bing Zhang (Dryopteridaceae), is described and illustrated from limestone cliffs in northern Guizhou Province, China. Polystichum loratum is most similar to P. yaanense Liang Zhang & Li Bing Zhang in having narrowly ovate to lanceolate abaxial rachis scales. The new species is distinguished by its lorate leaf lamina, the oblong to narrowly ovate microscales (broad-type) on abaxial pinna surfaces, and the exindusiate soli, while P. yaanense has lanceolate leaf lamina, subulate microscales (narrow-type) on abaxial pinnae, and indusiate son. Polystichum loratum is considered to be Critically Endangered (CR), based on IUCN Red List criteria
Three new species of the fern genus Pteridrys (Tectariaceae) from Vietnam
No full textThe fern genus Pteridrys is characterized by having free veins and a tooth on each sinus between two pinna or pinnule lobes. This genus is currently known from nine to ten species. Here we add three new species of Pteridrys from northern Vietnam found in an expedition in 2013
Polystichum hubeiense (Dryopteridaceae), a new fern species from Hubei, China
No full textZhang, L., Zhu, Z. M., Gao, X. F. & Zhang, L. B. 2013: Polystichum hubeiense (Dryopteridaceae), a new fern species from Hubei, China. - Ann. Sot. Fennici 50: 107-110. A new fern species, Polystichum hubeiense Liang Zhang & Li Bing Zhang (Dryopteridaceae), is described and illustrated from limestone cliffs in western Hubei Province, China. Polystichum hubeiense is most similar to P. lanceolatum in having relatively small leaves and pinnae and similar pairs of pinnae per lamina. The new species is distinguished by having overlapping and papery pinnae that are dull adaxially and repand on the margin, while P. lanceolatum has contiguous and leathery pinnae that are lustrous adaxially and dentate and with hard spines on the margin
Polystichum clarinervium (subg. Haplopolystichum; Dryopteridaceae), a new fern from Emei shan, China
No full textA new fern species, Polystichum clarinervium, a member of P. subg. Haplopolystichum (Dryopteridaceae), is described and illustrated from Emei shan, Sichuan Province, Southwest China. The new species is similar to P. deltodon, but the former has pinnae slightly imbricate, pinna apex rounded, and veins clear, while the latter has pinnae not imbricate, pinna apex acute, and veins obscured. Polystichum clarinervium was found on a limestone slope under sparse forest at an elevation of 1300 m and is currently known from two small populations. It is classified as Critically Endangered (CR) following IUCN Red List criteria
Polystichum tiandengense (subg. Haplopolystichum; Dryopieridaceae), a New Cave Fern from Guangxi, China
No full textA new fern species, Polystichum tiandengense H. He & Li Bing Zhang (Dryopteridaceae), is described and illustrated from a limestone cave in the Guangxi Zhuangzu Autonomous Region, South China. Polystichum tiandengense is most similar to P. cavernicola. Li Bing Zhang & H. lie in having oblong to square pinnae with undulate margins, but the new species is distinguished by its pinnae mostly adjacent to each other or imbricating, and mostly sterile (vs. distant from each other and mostly fertile in P. cavernicola). Polystichum tiandengense is considered to be Critically Endangered (CR), based on RICN Red List criteria
Polystichum hainanicola (Dryopteridaceae), a new fern species from Hainan Island, China
No full textA new fern species, Polystichum hainanicola belonging to section Haplopolystichum (Dryopteridaceae), is described and illustrated from Hainan, the southernmost province of China. Polystichum hainanicola is most similar to P. guangxiense, but the former has pinnae with a length to width ratio of 2.5-2.7, lamina completely fertile and sori fewer than four above midrib of middle pinnae. In contrast, the latter has pinnae with a length to width ratio of ca. 3:1, lamina sterile in its lower portion and sori 6-11 above midrib of middle pinnae
Didymochlaenaceae: A new fern family of eupolypods I (Polypodiales)
No full textThe pantropical monospecific fern genus Didymochlaena had long been placed in the family Dryopteridaceae before the advent of molecular phylogenetics. Recent molecular studies confirmed that it is a member of eupolypods I, but its familial placement has been controversial. It has been resolved using molecular data either as a member of Hypodematiaceae or as sister to the rest of eupolypods I. In the present study we performed phylogenetic analyses (MP, ML, BI) based on DNA data from five plastid loci (atpA, rbcL, rps4-trnS, trnL, trnL-F) of 88 accessions representing 79 species in 20 genera of all 9 families currently recognized in eupolypods I as ingroup and 5 species from 3 families of eupolypods II as outgroups. Our analyses resolved Didymochlaena as sister to the rest of eupolypods I with strong support. The results of an analysis of nuclear 18S data available from GenBank did not contradict those based on plastid data. This resolution is consistent with its sorus/indusium shape and a previous phylogenetic analysis based on both plastid and nuclear loci. Sorus shape, spore characters, and chromosome number previously used to place the genus in Dryopteridaceae are in fact not synapomorphies of the family. Our study clearly showed that the family Didymochlaenaceae should be recognized and we hereby validate this name previously proposed by Ching
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