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1.
As a member of the Sanguisorbinae, taxonomically complicated Polylepis Ruiz & Pav. from the South American Andes is one of the few wind-pollinated genera of Rosaceae. Here, it is suggested that problems traditionally faced in species delimitation and phylogeny reconstruction may be in part due to a combination of weak reproductive barriers and the large distances that can be covered by genetic information as a result of wind pollination. The pattern of species distribution as well as molecular data (AFLP) of Polylepis were contrasted with those of an unrelated, insect-pollinated genus of similar species number and distribution, Minthostachys (Griseb.) Spach (Lamiaceae). In the present case, extensive pollen-mediated gene flow may explain the homogenization of genetic variability over larger distances and a lower number of species restricted to individual countries in the wind-pollinated genus Polylepis, but more examples will have to be studied before arriving at final conclusions.  相似文献   

2.
Representatives from 11 Petunia Jussieu species in south and southeast Brazil were compared with two Calibrachoa La Llave & Lex., one Bouchetia Dunal, and two Nierembergia Ruiz & Pav. taxa in relation to DNA molecular variability. A total of 4532 base pairs related to one nuclear, five plastidial and one mitochondrial systems was investigated. Petunia and Calibrachoa, although separated among themselves, clearly differentiate from the two other genera. Despite the fact that the Petunia species do not show marked molecular differences, they can be separated in two complexes, in good agreement with altitude data. Petunia + Calibrachoa should have diverged from other clades at about 25 million years before present.  相似文献   

3.
Burmeistera, Centropogon, and Siphocampylus together comprise more than 500 species endemic to the Neotropics, Current knowledge of these genera is unsatisfactory, with much diversity yet to be described. Over the past seven years, one out of every 28 specimens received for identification has represented a new species, many characterized by unique or unusual character states. Siphocampylus smilax (Bolivia) is unique in the genus in its parallelodromous leaf venation and extra-floral nectaries. Centropogon dianae (Peru) cannot be accommodated in any recognized infrageneric taxon, and a new section, Centropogon sect. Niveopsis, is proposed for it. The flowers of C. steinii (Ecuador) are the smallest known in the genus, while C. connatilobatus (Venezuela) is the first species to combine arbusculiform pubescence and connate calyx lobes. Burmeistera venezuelensis is only the second species of the genus known to occur in Venezuela and the first to be endemic; similarly, Centropogon wilburii is only the third species of Centropogon known from Mexico and the first to be endemic to that country. Additional novelties are also described.  相似文献   

4.
Summary  Three closely affiliated species of Heterospathe Scheff. (H. elegans (Becc.) Becc., H. humilis Becc. and H. versteegiana Becc.) from New Guinea are revised. They are reduced to a single species which is divided into two subspecies, and the new combination H. elegans subsp. humilis (Becc.) M. S. Trudgen & W. J. Baker is made. The subspecies can be readily distinguished by their growth habit. Epitypes are designated for the three previously published names, as informative material on the habit is not included in the existing type specimens. A new, potentially related species is described as H. pullenii M. S. Trudgen & W. J. Baker.  相似文献   

5.
Botanical exploration in southwestern Amazonia has revealed a new species, Spondias testudinis J. D. Mitch. & Daly, described and illustrated here. Its distribution appears to be restricted to the Brazilian state of Acre; Pando in Bolivia; and Huánuco and Ucayali in Peru. The sexuality of the flowers of Spondias and its implications regarding their morphology is discussed. A provisional key to the neotropical species is presented.  相似文献   

6.
Summary  Based on previously published phylogenetic research, the genus Calospatha Becc. (Calamoideae) is placed in synonymy within Calamus L. The new combination, Calamus calospathus (Ridl.) W. J. Baker & J. Dransf. is made.  相似文献   

7.
N. Soethe  J. Lehmann  C. Engels 《Plant and Soil》2006,279(1-2):173-185
Root architecture of tree species was investigated at two different altitudes in tropical forests in Ecuador. Increasing altitude was accompanied by higher wind speeds and more shallow soils, while slope angles of both sites were comparable (20–50°). Three tree species typical for the montane forest at 1900 m (Graffenrieda emarginata (Ruiz & Pav.) Triana (Melastomataceae), Clethra revoluta (Ruiz & Pav.) Spreng. (Clethraceae), Vismia tomentosa Ruiz & Pav. (Clusiaceae)) and for the elfin forest at 3000 m (Weinmannia loxensis Harling (Cunoniaceae), Clusia spec. (Clusiacaea) Styrax foveolaria Perkins (Styraceae)) were examined. At 1900 m, 92% of the trees grew upright, in comparison to 52% at 3000 m. At 3000 m, 48% of the trees were inclined, lying or even partly uprooted. At this altitude, all trees with tap roots or with shoots connected by coarse rhizomes, 83% of the trees with stilt roots, and 50% of the trees in which stems or roots were supported by other trees grew upright, suggesting that these characteristics were relevant for tree stability. Root system morphology differed markedly between altitudes. In contrast to 1900 m, where 20% of structural roots originated in the deeper mineral soil, root origin at 3000 m was restricted to the forest floor. The mean ratio of root cross sectional area to tree height decreased significantly from 6.1 × 10−3 m2 m−1 at 1900 m to 3.2 × 10−3 m2 m−1 at 3000 m. The extent of root asymmetry increased significantly from 0.29 at 1900 m to 0.62 at 3000 m. This was accompanied by a significantly lower number of dominant roots at 3000 m (2.3 compared to 3.8 at 1900 m). In conclusion, native tree species growing in tropical montane and elfin forests show a variety of root traits that improve tree stability. Root system asymmetry is less important for tree stability where anchorage is provided by a deep and solid root–soil plate. When deep rooting is impeded, root traits improving the horizontal extension of the root–soil plate are more pronounced or occur more frequently. Furthermore, mutual mechanical support of roots and stems of neighboring trees seems to be an appropriate mechanism to provide anchorage in soils with low bulk density and in environments with high wind speeds.  相似文献   

8.
9.
Kerry Barringer 《Brittonia》1991,43(4):240-252
Epidendrum subgenusEpidanthus (L. O. Williams) Barringer (Orchidaceae) is a group of small, slender-stemmed epiphytes formerly classified in the genusEpidanthus L. O. Williams. The seven species are distributed from southern Mexico to Columbia in wet forests, usually above 1000 m in elevation. Species of subgenusEpidanthus are distinguished from the rest ofEpidendrum by their linear leaves, slender stems, and two pollinia. The new speciesEpidendrum aurigineum is described and the new nameEpidendrum, insolatum is created forE. crassum (Dressler) Mora-Retana & J. García.  相似文献   

10.
Described as new areHypolytrum pallidiceps, a clearcut species from Guyana,Oreobolus ecuadorensis, an ally ofO. obtusangulus from Ecuador, andScleria millespicula of the sectionOphryoscleria from Brazilian Amazonia.Oreobolus venezuelensis andScleria sprucei are newly added to the floras of Colombia and Venezuela respectively. Part I. Jap. J. Bot.20(2): 123–134. 1969.  相似文献   

11.
12.
T. marconae is described as a new species from the Peruvian coastal desert. Its systematic position betweenT. paleacea Presl em.L. B. Smith andT. purpurea Ruiz & Pavon is discussed.
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13.
A catalogue and a key to the non-lichenized, bulbilliferous basidiomycetes are given. The new genus Burgella is described for the lichenicolous B. flavoparmeliae, phylogenetically close to Sistotrema oblongisporum and Multiclavula. The genera Pneumatospora and Tricellulortus are placed in synonymy of Minimedusa, the new combination M. obcoronata is proposed, and the new facultative lichenicolous M. pubescens is described. The new facultative lichenicolous Burgoa angulosa is phylogenetically close to the generic type B. verzuoliana, whilst the new B. moriformis and B. splendens are provisionally included in the genus Burgoa. A Burgoa-like species in the Ceratobasidiaceae is left unnamed. Two new species of Marchandiomyces, M. buckii and M. nothofagicola, are described. As Marchandiomyces aurantiacus is phylogenetically more close to Erythricium than to Marchandiomyces, it is proposed to exclude it from that genus and to use the holomorphic generic name Marchandiobasidium for both anamorph and teleomorph of this species. The new genus Marchandiomphalina is introduced for the lichenized Omphalina foliacea, a taxon phylogenetically close to Marchandiobasidium. Taxonomic novelties Burgella Diederich & Lawrey; B. flavoparmeliae Diederich & Lawrey; Burgoa angulosa Diederich, Lawrey & Etayo; B. moriformis Diederich, Ertz & Coppins; B. splendens Diederich & Coppins; Marchandiomphalina Diederich, Lawrey & Binder; Marchandiomphalina foliacea (P. M. J?rg.) Diederich, Lawrey & Binder; Marchandiomyces buckii Diederich & Lawrey; M. nothofagicola Diederich & Lawrey; Minimedusa pubescens Diederich, Lawrey & Heylen; M. obcoronata (B. Sutton, Kuthub. & Muid) Diederich & Lawrey  相似文献   

14.
Pictolejeunea reginae, a new species from Venezuela is described and illustrated. It is the type of the new subgenusNeopitolejeunea Ilkiu-Borges, which is characterized by entire underleaves. A key to the two subgenera and four known species ofPictolejeunea is provided.
Ilkiu-Borges, A. L. (Museu Paraense Emílio Goeldi, C. P. 399, Belém, Pará, CEP 66040-170. Brasil: email: ilkiuborges@hotmail.com).Pictolejeunea reginae, a new species of Lejeuneaceae (Hepaticae) from Venezuela. Brittonia 54: 318–321. 2002.—Pictolejeunea reginae, uma nova espécie encontrada na Venezuela, é descrita e ilustrada. A espécie é tratada como tipo do novo subgêneroNeopictolejeunea Ilkiu-Borges, caracterizada pelos anfigastros inteiros. é apresentada uma chave para os dois subgêneros e as quatro espécies dePictolejeunea.
  相似文献   

15.
Chiliotrichiopsis peruviana Nesom, H. Rob. & Granda, a new species from Dept. Ayacucho in southwestern Peru, is described and illustrated. It is the only rayless species of the genus, now expanded to four species, and the only one that occurs outside of Argentina.Chiliotrichiopsis is one of six shrubby South American genera of Astereae (subtribe Hinterhuberinae) with paleate receptacles. Observations on morphology and a key to these genera provide perspective for the generic placement of the new species.  相似文献   

16.
A new synthetic species,Cucumis hytivus J.-F. Chen & J. H. Kirkbr. (2n=38), obtained by doubling the number of chromosomes in the sterile interspecific F1 hybrid (2n=19) betweenC. sativus L. (2n=14) andC. hystrix Chakr. (2n=24), is described.  相似文献   

17.
廖苗  曾思金  唐光大 《广西植物》2022,42(10):1717-1729
秦岭藤属(Biondia Schltr.)是中国特有属,约13种,驼峰藤属(Merrillanthus Chun&Tsiang)是仅在我国与柬埔寨分布的单种属,目前两个属均被归并到白前属(Vincetoxicum Wolf),由于取样和系统发育分析尚存一些欠缺,因此其系统位置和归属尚需进一步确认。该文使用2个核糖体基因序列片段(ITS、ETS)、5个叶绿体基因序列片段(psbA-trnH、trnG、trnL、trnL-F、trnT-L),以及二者的合并数据,重建娃儿藤亚族(Tylophorinae)(包含属的模式秦岭藤[B.chinensis Schltr.=V.shaanxiense(Schltr.) Meve&Liede]与驼峰藤[M.hainanensis Chun&Tsiang=V.hainanense(Chun&Tsiang) Meve, H. H. Kong&Liede])的系统发育树。结果表明:秦岭藤属与驼峰藤属均包含在白前属中,秦岭藤与青龙藤[B.henryi(Warb.) Tsiang&Li=V.henryi(Warb....  相似文献   

18.
Summary  Three new species of Abarema Pittier (Leguminosae) are described and illustrated: A. villosa Iganci & Morim, A. limae Iganci & Morim and A. barnebyana Iganci & Morim from the Brazilian states of Rio de Janeiro, Minas Gerais and Espírito Santo. A. villosa is similar to A. brachystachya (DC.) Barneby & J. W. Grimes, but has villous leaflets, a pilose and truncate ovary and a corolla three times longer than the calyx. Both A. limae and A. barnebyana resemble A. jupunba (Willd.) Britton & Killip in having rhombic leaflets and heteromorphic inflorescences, but are differentiated by leaflet size and indumentum, and pod size and shape.  相似文献   

19.
20.
Except for a robust habit, two specimens ofAloina collected in northern Argentina are morphologically similar and are tentatively attributed toA. rigida (Hedw.) Limpr. This represents an addition to the moss flora of Argentina. In addition, two specimens ofAloinella represent significant findings: one shows features that agree with those given in the protologue forA. galeata (Müll. Hal.) Broth. and is treated here asA. galeata var.galeata to show the relationship toA. galeta var.andina (Delgad.) Delgadillo & Schiavone stat. nov.; the other belongs inA. cucullifera (Mitt.) Steere, a new record for Argentina. A key to the known species ofAloinella with updated ranges is included.  相似文献   

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