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Arisaema species exhibit gender diphasy, or sex change, where individual plants produce either male, monoecious or female inflorescences depending on their size. Three basic sex-change patterns have been described in Arisaema. Type I species change between male and monoecious phases, type II species change between male, monoecious and female phases, while type III species change between male and female phases. Theoretical models suggest that sex ratios should be biased toward males, the sex with the lowest cost of reproduction. The goal of this study was to examine sex-ratio variation among Arisaema species that differ in sex-change patterns. Data from an extensive literature review, consisting of all available studies reporting Arisaema sex ratios, were combined with data from extensive field surveys of Arisaema dracontium and Arisaema triphyllum in southern Indiana, USA. This data set contains nearly 30 000 plants from 12 species. All species conformed to either the type I or type III pattern of sex change. There was little evidence for a distinct type II pattern of sex change, given that plants with monoecious inflorescences were rare relative to plants with pistillate inflorescences. The mean sex ratio in type I species (79.9% male) was significantly greater than in type III species (63.7% male). The data are consistent with the prediction that type I species are likely to have greater costs associated with female reproduction. We suggest that all Arisaema species have similar patterns of floral development, but differ in their ontogenetic patterns for male and female flowering.  相似文献   

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Arisaema lushuiense G. W. Hu & H. Li, a new species of Araceae from Gaoligong Mountains in northwestern Yunnan, China, is described and illustrated. It is similar and closely related to A. auriculatum Buchet, but differs by its basically green spathe with semi‐rotund to broadly ovate, 6–8 mm long auricles; the appendix of the spadix is 3.5–5.0 cm long and the apex of the appendix depressed with faint longitudinal ridges and grooves, slightly curved forward, with purplish black color, and exserted 1.0–1.5 cm from the spathe throat.  相似文献   

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Five new species named Peliosanthes aperta, P. elegans, P. kenhillii, Tupistra densiflora and T. patula are described and illustrated. These species are very local in distribution and endemic to northern or southern Vietnam. Two other species, Ophiopogon ogisui and Peliosanthes griffithii, are recorded as new to the flora of Vietnam. A key to the species of Tupistra occurring in Indochina and its neighboring regions is also provided.  相似文献   

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Aristolochia bidoupensis Do sp. nov. is newly described. This new species, currently only known from southern Vietnam, is most similar to Aristolochia faviogonzalezii (northern Vietnam) and A. moupinensis (China), but can be distinguished from the latter two by the following characters: flowers terminal, axillary, solitary, peduncle 1.3–1.5 cm long, bracteole ovate, 3–4 × 2–3 mm, limb discoid‐shaped with three expanded lobes, not revolute, internal surface uniformly dark purple, smooth, throat uniformly golden without dots. Morphological characters such as a 3‐lobed gynostemium and a 3‐lobed limb place the new species in A. subgen. Siphisia.  相似文献   

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Lin J  Zhou X  Pang Y  Gao H  Fei J  Shen GA  Wang J  Li X  Sun X  Tang K 《Bioscience reports》2005,25(5-6):345-362
A novel agglutinin gene was cloned from Arisaema lobatum using SMART RACE-PCR technology. The full-length cDNA of Arisaema lobatum agglutinin (ala) was 1078 bp and contained a 774 bp open reading frame encoding a lectin precursor (proproprotein) of 258 amino acid residues with a 23 aa signal peptide. ALA contained three mannose-binding sites (QXDXNXVXY) with two-conserved domains of 45% identity, ALA-DOM1 and ALA-DOM2. The three-dimensional structure of ALA was very similar to that of GNA (Galanthus nivalis agglutinin). ALA shared varying identities, ranging from 40% to 85%, with mannose-binding lectins from other species of plant families, such as Araceae, Alliaceae, Iridaceae, Lillaceae, Amaryllidaceae and Bromeliaceae. Genomic sequence of ala was also cloned using genomic walker technology, and it was found to contain three putative TATA boxes and eight possible CAAT boxes in the 5′-flanking region. No intron was found within the region of genomic sequence. Southern blot analysis indicated that the ala belonged to a multi-copy gene family. Expression pattern analysis revealed that the ala preferentially expressed in the tissues with the higher expression being found in spadix, bud, leaf, spathe and tuber. The cloning of the ala gene not only provides a basis for further investigation of its structure, expression and regulation mechanism, but also enables us to test its potential role in controlling pests and fungal diseases by transferring the gene into plants in the future.  相似文献   

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Aspidistra obtusata is described and illustrated as a new species from southern Vietnam. The new species resembles A. truongii, but differs in smaller diameter of perigone (12.6–14.9 mm vs 25–35 mm), shape of tepals (elliptic, obtuse vs triangular‐ovate) and pistil (widely obconic vs mushroom‐shaped). A molecular characterization of the new species (based on data of plastid psbA‐trnH and nuclear 5S‐NTS regions) is also given, and compared with the most similar congeners.  相似文献   

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A new species of Magnolia sect. Gwillimia DC., Magnoliaceae from Vietnam is described and illustrated. Magnolia tiepii is recognized from southern Vietnam, where it occurs in Khanh Vinh slope, Khanh Vinh District, Khanh Hoa Province. It is distinguished from the closely related M. henryi by having narrowly cuneate leaf blade, short petiole, stipular scar at the base of the leaf blade, short peduncle and ellipsoid fruit.  相似文献   

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Research on the phylogeny of a distinct group of Andean Senecio, previously considered as Lasiocephalus, resulted in the discovery of two new species, which are here described and illustrated. Senecio josei Sklená?, which grows in rocky habitats in grass páramo in southern Ecuador, is characterized by linear leaves and a racemose or paniculate synflorescence. Senecio superparamensis Sklená? is characterized by grayish–white pubescence, solitary capitula and leafy stems, and inhabits superpáramos in northern and central Ecuador.  相似文献   

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Species diversity of Ulva in Vietnam was investigated using three commonly used genetic markers, the nuclear encoded rDNA ITS region and the plastid encoded rbcL and tufA genes. Single locus species delimitation methods, complemented with morphological and ecological information resulted in the delimitation of 19 species. This diversity is largely incongruent with the traditional understanding of Ulva diversity in Vietnam. Only four species identified in this study, U. lactuca, U. reticulata, U. spinulosa, and U. flexuosa, have been previously reported, and seven species, U. ohnoi, U. tepida, U. chaugulii, U. kraftiorum, U. meridionalis, U. limnetica, and U. aragoënsis, are recorded for the first time from Vietnam. Seven genetic clusters could not be associated with species names with certainty. A new species, U. vietnamensis, is described from marine to brackish coastal areas from southern Vietnam based on its morphological and molecular distinctiveness from the currently known Ulva species. A comparison with recent molecular-based studies of Ulva diversity showed that species composition in Vietnam is similar to that of adjacent countries, including Japan, China, as well as Australia. Our study emphasizes the importance of molecular data in the assessment of Ulva diversity, and indicates that a lot of diversity may still remain to be discovered, especially in tropical regions.  相似文献   

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祝正银 《广西植物》2011,31(5):572-574
描述了四川西部天南星属(天南星科)植物一新种,即川西天南星.  相似文献   

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Three new species of Synargis Hübner, 1819, from Paraguay and southern and central Brazil are described: Synargis fandanga sp. nov. from Paraguay (Amambay and Paraguari) and southern Brazil (Paraná and Santa Catarina), Synargis rasqueada sp. nov. from central Brazil (Mato Grosso), and Synargis gorpa sp. nov. from southern Brazil (Paraná, Santa Catarina, and Rio Grande do Sul). Lectotypes are designated for Lemonias axenus Hewitson, 1876, Ematurgina axenus ochrophlegma Sitchel, 1911, Ematurgina acervata Seitz, 1932, and Ematurgina perrupta Seitz, 1932. Ematurgina ochrophlegma f. dissimilis Hayward, 1949, is a new synonym of Synargis bifasciata (Mengel, 1902), and Ematurgina ochrophlegma f. distincta Hayward, 1949, is a new synonym of Synargis axenus (Hewitson, 1876). The revalidation of E. perrupta Seitz, 1932, and the new status Synargis ochrophlegma (Stichel, 1911) are proposed. Ematurgina perrupta ab. roeberi Seitz, 1932, and Ematurgina bifasciata ochrophlegma ab. leucomelaina Breyer, 1930, are considered unavailable names. Based on a previous phylogenetic hypothesis, the phylogeny of the genus Synargis is reassessed, adding these new and revalidated taxa, and nine additional characters. The ‘Synargis regulus’ species group and the ‘Synargis axenus complex’ are recovered as monophyletic, with S. gorpa sp. nov. sister to the remaining species of the ‘S. axenus complex’. Additionally, an up‐to‐date geographical distribution map and a dichotomous key are provided, and the taxonomy of the taxa involved is discussed. © 2013 The Linnean Society of London  相似文献   

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Summary

The Chinese species of the genus Coenochilus Schaum, 1841 are revised, including a new species, C. pilosus n. sp. described from southern China (also from Vietnam and Laos). The lectotype for Coenochilus uncinatipes Moser, 1915 is designated, and this name is recognized as a junior synonym of C. bifoveolatus Fairmaire, 1888. Previously published synonymy of Coenochilus apicalis Westwood, 1873 and C. armiger Westwood, 1873 is confirmed based on the examination of type specimens. The neotype of C. tonkinensis Moser, 1910 is designated, and C. clinteroceroides Jákl, 2015 is synonymized with this species. Coenochilus tonkinensis is newly recorded from China, while Chinese records of C. nitidus Arrow, 1910 are verified as misidentification of C. striatus Westwood, 1873, thus C. nitidus is removed from the Chinese fauna. Diagnoses and illustrations are provided for all five Chinese species. A key to Chinese species and new distribution records are also presented.??  相似文献   

15.
天南星属植物的花粉形态   总被引:2,自引:1,他引:1  
利用扫描电镜对天南星科天南星属(Arisaema)8组25种植物的花粉进行研究(其中,12种前人未观察过,12种中11种为我国特有)。结果显示:本属花粉形态基本一致,即球形,无萌发孔,无覆盖层,具微刺,是一个非常自然的类群。但各个种在花粉粒大小,刺长,刺的形状,刺基部上径,刺的密度和刺间纹饰方面差别较大,可以作为区别种的依据。这进一步证实了前人的结论。花粉形态支持学者们关于天南星属是本科最进化的类群之一的观点。天南星属花粉可能由线花组从花粉大小适中、刺密度居中向大或小、密或疏的方向发展;刺间表面纹饰对探讨组间演化关系意义不大。Murata等对于花粉刺间具较密颗粒为曲序组特征的界定可疑;把A.yunnanense Buchet、A.bathycoleum Hand.-Mazt.和A.prazeri Hook.f.归入曲序组似乎不妥。A.consanguineum Schott和A.fraternum Schott的花粉形态没有支持李恒对这两个种的归并。  相似文献   

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The genus Miliusa in Cambodia and Vietnam is reviewed. Cambodia and Vietnam each harbors six species of Miliusa, including three which are described as new to science: one from Cambodia (Miliusa cambodgensis sp. nov.), the other two from Vietnam (M. astiana and M. ninhbinhensis spp. nov.). In addition, a complete nomenclature and relevant information about the Miliusa species previously known from Cambodia and Vietnam are provided, including keys to the Cambodian and Vietnamese species, the designation of a lectotype for M. baillonii and the synonymization of M. balansae var. elongatoides, M. chunii and M. sinensis with M. balansae.  相似文献   

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The family Petrosaviaceae is represented by two species in Vietnam, viz. Petrosavia sakuraii restricted to the northern part of the country and P. stellaris distributed in its southern part. The latter species is shown to possess a wide range of distribution in Vietnam, though it was previously believed to be an exclusively Malesian species. The inclusion of P. sinii in P. sakuraii is confirmed. Details on distribution, illustrations and an identification key for these species are provided.  相似文献   

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Currently, 20 species of the genus Rhyacophila are known from Vietnam. Of these, 17 species are distributed among eight species groups, with three species unassigned. Examination of material collected by personnel of the Royal Ontario Museum in Toronto, Canada has revealed six new species and five new records of Rhyacophila from Vietnam, distributed among six species groups, four of which are new to Vietnam. Newly described species include: Rhyacophila smithi, Rh. curriei, Rh. laocai, Rh. meyi, Rh. olahi, and Rh. fernandi. Rhyacophila bidens Kimmins, Rh. inaequalis Denning and Schmid, Rh. lhabu Schmid, Rh. malayana Banks, and Rh. rhombica Martynov are recorded from Vietnam for the first time. The females of four species, Rh. bidens, Rh. immaculata Mey, Rh. malayana Banks, and Rh. tamdaona Oláh, are described for the first time. All 31 species of Rhyacophila now known from Vietnam are included in this work, organized by branch and species group.  相似文献   

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