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1.
Plagiochila dubia Lindenb. & Gottsche is reduced to a synonym of the Neotropical P. patula (Sw.) Lindenb. Specimens from the Canary Islands and Madeira proved to belong to the eastern North American P. virginica A.Evans, new to Europe. Phylogenetic analyses of the internal transcribed spacer regions (ITS1-5.8S-ITS2) of nuclear ribosomal DNA of ten Plagiochila species produced four independent lineages that are well supported by all bootstrap analyses (maximum likelihood, maximum parsimony, and distance). These lineages correspond with the Plagiochila sections Arrectae, Contiguae, Cucullatae and Glaucescentes. Spruce's “Ramiflorae” and “Cauliflorae” may no longer be regarded as monophyletic units of Plagiochila. Received August 19, 2001 Accepted October 11, 2001  相似文献   
2.
To examine geographic differentiation in Asarum heterotropoides var. heterotropoides in Hokkaido Is. in the northern Japan, in which two putative cryptic species have been suspected to exist, extensive and detailed morphological research on 794 individuals from 44 populations throughout Hokkaido Is. was performed. Among the characters examined, the angle between and tip shape of the calyx lobes and the supratecta of the pollen grains were significantly correlated and were found in similar geographic clines. Among them, the pollen showed two discrete states in almost distinct distribution. Multidimensional scaling analysis showed that individuals within each of the two pollen types had different trends in flower characters. Consequently, we assumed a cline from south to north on Hokkaido Is. For the causes of the cline, the two hypotheses were proposed, primary geographic differentiation or extensive introgressive hybridization between two distinct geographical species existing in the past.  相似文献   
3.
金线草的系统位置一直存在争议,该试验以Triplaris weigeltiana为外类群,采用最大简约法对金线草及其近缘类群的ITS序列进行了系统发育分析.结果表明:(1)金线草和蓼属的春蓼组、刺蓼组形成三个并列的分支,因此,金线草没有必要独立成属,分子证据支持金线草成立为组;(2)金线草和春蓼组、刺蓼组植物聚在一起,...  相似文献   
4.
Saxifraga L. is the largest genus in Saxifragaceae and a characteristic component of the herbaceous flora of the temperate and alpine mountains in the Northern Hemisphere. Section Irregulares is a small group of 15–20 species, representing one of the early‐diverged lineages in the genus characterized with unique zygomorphic flowers. We used both nuclear internal transcribed spacer and chloroplast DNA regions (psbA‐trnH, trnL‐F, and matK) to reconstruct its species relationships, estimate divergence times, and infer its historical biogeography. Our phylogenetic results corroborate the monophyly of sect. Irregulares and its sister relationship to sect. Heterisia from North America. The section was well resolved into two lineages corresponding to their morphological features and biogeographic distributions. One represents ser. Stoloniferae including S. stolonifera Curtis and S. nipponica Makino with long‐creeping stolons/rhizomes and small petals with spots and the other comprises the remaining taxa (ser. Rufescentes) which lack long‐creeping rhizomes. Spots on leaves (abaxially spotted vs. abaxially without spots) and spots on petals (without spots vs. with spots) are inferred to be phylogenetically informative within ser. Rufescentes. Divergence time estimates and ancestral area analysis suggested a western North American origin of sect. Irregulares with migration into East Asia by way of the Bering land bridge in the Middle Oligocene. The development of drying and desertification belt in the late Miocene could have played an important role in the subsequent restriction and separation of the north and south lineages within eastern Asia.  相似文献   
5.
Clematis sect. Atragene is revised in this paper based on the examination of a large number of herbarium specimens, extensive field observations, and morphometric analyses. Brief taxonomic history and geographical distribution of the section are given, the relationships among the species are discussed, and the evolutionary trends of some characters in the section are evaluated. The staminodes of the plants in this section may have evolved from the outer stamens with petaloid filaments and gradually disappearing anthers. Subsequently, they may have evolved in two different ways. One possibility is that the staminodes elongate and become lanceolate, as long as sepals, and their apices turn into attenuate. The other is that the staminodes are spathulate, but not elongating, as long as stamens, and their apices turn into retuse from obtuse and rounded. The evolutionary trend of sepals may be from thin to thick in texture, and the veins from non-prominent to prominent. As a result, five new series are established and nine species, two subspecies and nine varieties (including three new ranks) are recognized in this section. An identification key is provided, and each taxon is described and illustrated. Clematis sibirica and Clematis ochotensis are treated as subspecies of Clematis alpina due to their subtle differences and lack of, or few, overlapping distributions. Clematis fusijamana and Clematisfauriei are recognized as varieties of C. alpina ssp. ochotensis for the continuous variation of the velutinous strips on the sepal margins. Clematis iliensis is treated as variety of C. alpina ssp. sibirica for the continuous variation of leaf division types. Extensive variations in sepal color and basal caruncle size support degrading Clematis chiisanensis as a variety of Clematis koreana. The North American ser. Occientales may be primitive, whereas ser. Macropetalae may be the most advanced taxon in this section. Ser. Alpinae and ser. Koreanae are closely related to each other. However, the systematic position of ser.  相似文献   
6.
7.
对新种丽花兰Cymbidium concinnum Z. J. Liu &; S. C. Chen和新变种龙州兰C. eburneum var. longzhouense Z. J. Liu &; S. C. Chen进行了描述和绘图; 丽花兰与大雪兰C. mastersii Griff. ex Lindl.有亲缘关系, 区别点在于新种叶片先端不分裂, 花序具18-22朵花, 唇瓣中裂片上有一个V型的紫红色斑块; 龙州兰(变种)与独占春(原变种)的主要区别在于唇瓣中裂片上和侧裂片顶部有较密的紫红色斑。对象牙白C. maguanense的分类问题进行了讨论, 并为其指定了新模式; 还为腋花组sect. Eburnea国产种类提供一个检索表。  相似文献   
8.
越南铁线莲属一新种   总被引:3,自引:0,他引:3  
本文描述的产于越南的毛茛科Ranunculaceae铁线莲属Clematis一新种C. hagiangensis N. T. Do是欧亚大陆第一个具单性花的种, 在花构造方面与单性铁线莲组单性铁线莲亚组sect. Aspidanthera Spach subsect. Dioicae (Prantl) W. T. Wang的种类近缘, 但叶均为单叶, 萼片呈卵形或宽卵形而不同。在单性铁线莲亚组的种, 叶通常为复叶, 只在C. dimorphophylla W. T. Wang和C. variifolia W. T. Wang同时为单叶和复叶, 此外萼片呈长圆形、倒披针形或狭卵形。  相似文献   
9.
Astragalus mario-sousae is described from the central part of state of Nuevo León, Mexico. It differs fromAstragalus esperanzae by its habit, peduncles, pedicels, and fruits.
Resumen   Astragalus mario-sousae (Fabaceae: Galegeae), a new species from northeastern Mexico. Brittonia 57: 314–319. 2005.—Astragalus mario-sousae es propuesta como especie nueva. Se conoce solo de la porción central del estado mexicano de Nuevo León. Se presentan una descripción e ilustración. Difiere deAstragalus esperanzae por su hábito erecto, pedúnculos, pedicelos y frutos más cortos.
  相似文献   
10.
河南槭叶铁线莲(毛茛科)一新变种——无裂槭叶铁线莲   总被引:11,自引:0,他引:11  
报道了槭叶铁线莲一新变种——无裂槭叶铁线莲Clematis acerifolia Maxim. var. elobata S. X. Yan。该变种与原变种不同在于植株较矮,高不超过20 cm,叶卵形至宽卵形,不分裂,基部宽楔形至近截形,边缘具不规则锯齿。  相似文献   
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