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1.
Abstract. One invalid lectotype designation proposed in a recent revision of European species of Copidosoma is validated ( Encyrtus geniculatus Dalman) and four incorrectly cited designations are corrected ( C. peninsulare Mercet, E. filicornis Dalman, E. flagellaris Dalman, E. machaeras Walker). One species, C. tremblayi , is described as new. 相似文献
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Gilberto Morillo 《Nordic Journal of Botany》1994,14(3):283-286
Two new species of Asclepiadaceae, Cynanchum ellemannii and Gonolobus saraguranus , collected by Lis Elleman the "Aarhus University Ecuador Project" as part of an ethnobotanical study in the Province of Loja, are here described and illustrated. Moreover, the new name Cynanchum trianae is proposed. 相似文献
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Eriocaulon peninsulare, a new species allied to E.sexangulare from Anshi National Park, Karnataka is described and illustrated. 相似文献
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色季拉山柳兰属观赏植物资源调查及网脉柳兰育苗技术研究 总被引:1,自引:0,他引:1
2007-2008年,在西藏色季拉山先后进行了3次柳兰属Chamaenerion观赏植物资源的调查,并于2008年进行了网脉柳兰C.conspersum的育苗试验,调查和试验结果发现:(1)色季拉山有两种观赏价值较高的柳兰属植物,分别是柳兰C.angustifolium、网脉柳兰,而宽叶柳兰C.latifolaum的分... 相似文献
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狗尾草属野生近缘种的染色体鉴定 总被引:7,自引:3,他引:4
对来自多个国家和地区的10个种(青狗尾草S.viridis,法氏狗尾草S.faberii,轮生狗尾草S.verticillata、S.verticillifor-mis,金色狗尾草S.glauca、S.pumila、S.grisebachii、S.leucopila、S.parviflora、S.queenslandica等)50份狗尾草材料进行了染色体计数及倍性鉴定。发现狗尾草属中的青狗尾草均为二倍体,金色狗尾草S.glauca有四倍体和八倍体,轮生狗尾草S.verticillata有二倍体和四倍体,法氏狗尾草S.faberii为四倍体,S.pumila有二倍体和四倍体,S.grisebachii为二倍体,S.leucopila为二倍体,S.queenslandica为四倍体。本研究中对S.grisebachii、S.leucopila、S.queenslandica3个种是首次染色体倍性观察。发掘近缘种的有益基因是作物育种的重要途径之一,本研究搜集的谷子近缘野生种对谷子远缘杂交育种和谷子起源进化分析有重要意义。 相似文献
7.
Evolution of herkogamy has been ascribed to preventing autonomous selfing within flowers, but this argument has received challenges due to the negative effects of sexual interference on reproductive success of plant species. We examined the effects of the two contrasting modes of herkogamy, detailed by the different patterns of style movement, on the foraging time of pollinators on flowers, pollen removal, and deposition in two Chamerion species. Our results suggested that the duration of foraging time of bumblebees was generally higher in C. angustifolium (L.) Holub than in C. conspersum (Hausskn.) Holub during the male-phase of flowers, but the reverse during the female-phase of flowers. As a result, stigma interfered with pollen removal more in C. conspersum than in C. angustifolium, based on examinations of pollen removal after one visit by a pollinator. However, this negative effect on total pollen removal was covered by the high pollinator diversity and the possible high visitation rate in the study sites. In contrast, we found that almost no difference existed in pollen deposition rate after one visit of a pollinator between the two Chamerion species, and emasculation did not increase the total pollen deposition in either species, indicating that anthers did not interfere with pollen deposition in the two Chamerion species. Our results suggested that, compared with C. conspersum, the derived mode of herkogamy in C. angustifolium reduced interference of stigmas in pollen removal. This might contribute to the wide distribution of C. angustifolium, to some degree, in environments of pollinator scarcity and low activity in newly colonized habitats. 相似文献
8.
Julian A. Steyermark 《Brittonia》1978,30(1):39-49
Ten new species (Billbergia manarae, Croizatia naiguatensis, Croton huberi, Rinorea oraria, Anaectocalyx manarae, Linociera avilensis, Cynanchum beatricis, C. manarae, Matelea costanensis, and M. manarae) are described in preparation for the forthcoming Flora of Avila and Naiguatá. 相似文献
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Bent Fredskild 《Nordic Journal of Botany》1984,4(4):475-480
Distribution maps of the Greenland Onagraceae and synecological notes are presented. Four species are low–arctic, most often or exclusively growing in the lowland. The northernmost occurrence of the three of them, Epilobium palustre, E. hornemannii and E. lactiflorum is at "hot springs" between 69° and 70° N, while the fourth, Chamaenerion angustifolium , with the same northern limit, does not show this preference. E. anagallidifolium is even growing two degrees of latitude further north, and besides it is not limited to the lowland. E. arcticum has an arctic distribution between 69° and 80° N, while the seventh species, C. latifolium , is circumgreenlandic, being rare only in the most oceanic part of N Greenland. The occurrence of E. alsinifolium in Greenland has been rejected. 相似文献
10.
Five new C21 steroidal glycosides, namely, komarosides D (1), E (2), F (3), G (4), and H (5), along with two known C21 steroidal glycosides cynatratoside E (6) and hancoside A (7), were isolated from the ethanol extract of the roots of Cynanchum komarovii Al.Iljinski (Asclepiadaceae). Their structures were determined by physiochemical and spectroscopic analysis. Among these glycosides, five had an aberrant 13,14:14,15-disecopregnane-type skeleton, and the other two had normal four-ring C21 steroid skeletons. The existence of more than one type of C21 steroid skeleton in one species is rare in the plants of the family Asclepiadaceae, and this has chemotaxonomic significance for this species. 相似文献
11.
Eriophorum vaginatum and E. angustifolium are dominant arctic sedges of the well-drained tussock tundra and the permanently flooded wet-sedge tundra, respectively. We determined diurnal courses of gas exchange and water relations of the two species in their natural habitat and compared their responses to changes in light, air temperature, and humidity. Mean photosynthetic response to light was similar between E. angustifolium and E. vaginatum and carbon gain in both species was light limited during most of the growing season. On sunny and dry days, both species closed stomata in response to high leaf-to-air vapor pressure deficits. Even though E. angustifolium was growing in standing water, it exhibited a tighter control of transpirational water loss and had lower hydraulic conductivity in the soil-root-shoot pathway than E. vaginatum. The different response pattern between the two species is discussed in the context of differences in habitat conditions. 相似文献
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Allozyme variation in the three extant populations of the narrowly endemic cycad Dioon angustifolium Miq. (Zamiaceae) from North-eastern Mexico 总被引:1,自引:0,他引:1
González-Astorga J Vovides AP Cruz-Angon A Octavio-Aguilar P Iglesias C 《Annals of botany》2005,95(6):999-1007
BACKGROUND AND AIMS: Dioon angustifolium was considered within D. edule. Recent morphometric and allozyme studies on D. edule have shown that D. angustifolium has originated from geographic isolation and is therefore considered to be a separate species. This cycad is endemic to north-eastern Mexico and is known only from three populations in the Sierra Madre Oriental mountain chain. Its populations are small when compared with its southern relative D. edule. In this study, genetic variation was determined within and between populations of D. angustifolium and the genetic consequences of habitat fragmentation and isolation of populations of this species were assessed. METHODS: Allozyme electrophoresis of 14 presumptive loci was used. The data were analysed with statistical approximations for estimating genetic diversity, structure, gene flow and recent genetic bottlenecks. KEY RESULTS: Means and standard deviations of genetic diversity estimators were: number of alleles per locus (A = 1.67 +/- 0.23), percentage of polymorphic loci (P = 52.4 +/- 23 %) and expected heterozygosity (H(E) = 0.218 +/- 0.093). The genetic variation attributable to differences among populations was 16.7 %. Mean gene flow between paired populations was Nm = 1.55 +/- 0.67, which is similar to that reported for endemic plant species of narrow geographical distribution and species with gravity-dispersed seed. A recent bottleneck is detected in the populations studied. CONCLUSIONS: Dioon angustifolium presents high levels of genetic diversity compared with other cycad species, in spite of small population sizes. The recent bottleneck effect did not effectively reduce the genetic variation to the extent of eliminating these populations. The distribution of D. angustifolium appears to be the result of historical biogeographical effects related to the Pleistocene glaciations. It is recommended that this species be catalogued in the IUCN Red List of Threatened Species and conservation efforts be made to preserve it. 相似文献
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采用石蜡切片法对伞形科(Apiaceae)棱子芹属(PleurospermumHoffm.)的宝兴棱子芹〔P.benthamii(Wall.ex DC.)Clarke〕和松潘棱子芹(P.franchetianumHemsl.)、西藏棱子芹(P.hookeriClarke var.thomsoniiClarke)和太白棱子芹(P.giraldiiDiels)、康定棱子芹(P.prattiiWolff)和瘤果棱子芹(P.wrightianumde Boiss.)的果实横切面的解剖结构特征进行了详细观察和比较分析。结果表明:6种植物虽然在外部形态上两两相似,但彼此间的果实解剖结构特征却存在一定的差异。共同特征是果棱均比较发达,且外果皮与中果皮分离,常形成空腔,每个果棱有1个明显的维管束,中果皮高度退化,果壁均很薄,棱槽和合生面均有油管,其中合生面油管数为棱槽油管数的2倍;差异主要表现在果实横切面外形、果体的压扁程度、果棱的发达程度、外果皮拱起程度及角质层的有无和厚度、维管束大小和着生位置、棱槽油管数以及合生面与侧棱的关系等方面。根据观察结果认为康定棱子芹与瘤果棱子芹不宜合并,建议将西藏棱子芹与太白棱子芹予以合并。 相似文献
14.
Flowers of Chamaenerion angustifolium, Geranium palustre and G. pratense are visited by more than 100 insect species. For all plants the spectrum of visitors is similar. However the role of insects species in pollination is different and depends on the stamen and stigma length, flexibility of pedicle and feeding behaviour of insect inside flower. The possibility to take and to transport pollen grains usually increase with the size of insect. The nature of this correlation is determined by stamen and stigma length. Pollinators of G. palustre with short stamens and stigmas are smaller than those of Ch. angustifolium and G. pratense. On the other hand, more flexible pedicle of G. palustre prevent the flowers from visits of big insects. Three plants studied by the authors are not equally attractive for different insect groups. Dense in fluorescence of Ch. angustifolium and G. pratense that usually are lifter under the grass are very attractive for foraging social insects (honey bee, bumblebee). Flies avoid long distance travelling and prefer single flowers located not far from each other. For instance G. palustre is more attractive for flies not for social bees. It is pollinated mainly by flies and solitary bees with average weight of 10-70 mg. The main pollinators of Ch. angustifolium and G. pratense are honey bees, bumblebees and wasps with average mass exceeding 70 mg. 相似文献
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产自齐云山的江西藓类植物新记录 总被引:2,自引:0,他引:2
报道了产自齐云山的江西藓类植物分布新记录14种2变种,它们是大曲柄藓(Campylopus hemitrichius)、粗叶青毛藓(Dicranodontium asperulum)、长叶青毛藓(D. didymodon)、大锦叶藓(Dicranoloma assimile)、锦叶藓(D. dicarpum)、曲肋凤尾藓(Fissidens oblongifolius)、爪哇凤尾藓(F. javanicus)、巴西网藓鞘齿变种(Syrrhopodon prolifer var. tosaensis)、阔叶桧藓(Pyrrhobryum latifolium)、狭叶蓑藓(Macromitrium angustifolium)、厚角黄藓宽边变种(Distichophyllum collenchymatosum[WTBZ] var. [WTBX]pseudosinense)、台湾多枝藓(Haplohymenium formosanum)、三列疣胞藓(Clastobryum glabresscens)、腐木藓(Heterophyllium affine)、细枝刺枝藓(Wijkia surcularis)、明叶藓(Vesicularia montagnei)。而且锦叶藓属(Dicranoloma)、疣胞藓属(Clastobryum)和腐木藓属(Heterophyllum)为江西新记录属。 相似文献
17.
JÜRG STÖCKLIN 《Botanical journal of the Linnean Society. Linnean Society of London》1992,108(1):35-47
STÖCKLIN, J., 1992. Differences in the location of subcotyledonary buds among Epilobium angustifolium L., E. dodonaei Vill. and E. fleischeri Hochst. (Onagraceae) and effects on architecture and population structure . Morphological and architectural features in the two closely related pioneer plant species Epilobium dodonaei and E. fleischeri are examined in cultivation and in the field and compared with E. angustifolium. In E. angustifolium , the aerial shoot system is renewed every year from buds on horizontal roots and results in a horizontal spread and a clonal growth form. In E. dodonaei , bud formation is restricted to the hypocotyl and in larger plants to the transitional region between root and shoot. Consequently this species shows no vegetative mobility and develops a shrub-like habit. The alpine E. fleischeri combines the habit of E. angustifolium and E. dodonaei and may either develop successive generations of shoots from the transitional region between root and shoot and/or exploit new areas by horizontal roots and the formation of shoots from root buds. The simple difference in the location of renewal buds is accentuated by cumulative growth. The study shows that E. dodonaei and E. fleischeri , which often are considered as subspecies, are separated by fundamental differences in their architectural models. The ecological and demographic implications of these differences are discussed. 相似文献
18.
Memecylon sivadasanii , a new species of Melastomataceae from India is described and illustrated. The new species is allied to M. angustifolium and M. rivulare. 相似文献
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The role of triploid hybrids in the evolutionary dynamics of mixed-ploidy populations 总被引:4,自引:0,他引:4
BRIAN C. HUSBAND 《Biological journal of the Linnean Society. Linnean Society of London》2004,82(4):537-546
Theory suggests that the evolution of autotetraploids within diploid populations will be opposed by a minority-cytotype mating disadvantage. The role of triploids in promoting autotetraploid establishment is rarely considered, yet triploids are often found in natural populations and are formed in experimental crosses. Here, I evaluate the effects of triploids on autotetraploid evolution using computer simulations and by synthesizing research on the evolutionary dynamics of mixed-ploidy populations in Chamerion angustifolium (Onagraceae). Simulations show that the fate of a tetraploid in a diploid population varies qualitatively depending on the relative fitness of triploids, the ploidy of their gametes and the fitness of diploids relative to tetraploids. In general, even partially fit triploids can increase the likelihood of diploid–tetraploid coexistence and, in some cases, facilitate tetraploid fixation. Within the diploid–tetraploid contact zone of C. angustifolium , mixed populations are common (43%), and often (39%) contain triploids. Greenhouse and field studies indicate that triploid fitness is low (9% of diploids) but variable. Furthermore, euploid gametes produced by triploids can be x , 2 x or 3 x and contribute the majority (62%) of new polyploids formed in each generation (2.3 × 10−3 ). Although triploid bridge, alone, may not account for the evolution of autotetraploidy in C. angustifolium , it probably contributes to the prevalence of mixed-ploidy populations in this species. Therefore, in contrast to hybrids in homoploid species, triploids may actually facilitate rather than diminish the fixation of tetraploids by enhancing the rate of formation. © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 82 , 537–546. 相似文献
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Steroidal glycosides from Cynanchum forrestii Schlechter 总被引:2,自引:0,他引:2
Nine new steroidal glycosides, cynaforrosides B, C, D, E, and F, based on a 13, 14: 14, 15-disecopregnane-type skeleton, cynaforrosides G, H, and I with a new aglycone named cynaforrogenin A, and cynaforroside J together with three known C21 steroidal glycosides cynatratoside A, hancoside and komaroside C were isolated from the ethanol extract of the roots of Cynanchum forrestii Schlechter. The structures of new compounds were determined on the basis of spectral and chemical evidence. Steroidal glycosides with three kinds of skeletons were isolated from this plant simultaneously. The sugar units of cynaforrosides B-I contained two moieties of glucoses and especially cynaforrosides E-I contained two glucoses with the mode of 1-->6 linkage, which were rare among steroidal glycosides of the genus Cynanchum. 相似文献