排序方式: 共有64条查询结果,搜索用时 15 毫秒
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正10年前,在所庆80周年前夕,我去昆明出差拜访了著名植物学家、植物所早期领导人之一吴征镒院士,他说:“今年是植物所成立80周年,代我向植物所表示祝贺!向全所同志们问候!”他特别强调:“昆明所和北京所是同根、同为一家,北京所是中国植物学的“航空母舰”。我理解吴老的意思是:(1)植物所在20世纪50年代分出了南京植物所(中山植物园)、庐山 相似文献
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赤瓟属(Thladiantha)是Bunge在1834年建立的,他根据采自北京地区的标本,命名为T.dunia Bunge作为属的模式种,发表时仅此一种。随后,不同的著者在该属下陆续发表了一些种。本世纪初,A. Cogniaux (1916),M. F. Ganepain (1918)分别对该属作了整理;接着,H. Handel-Mazzetti (1936),C. Jeffrey (1962)及本文前一作者(1975)也都作过研究,最近,C. Jeffrey (1980)对属的范围作了修正,并对种类作了文献式记载。 相似文献
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商陆科植物几种雌蕊类型的发育和结构进行了观察,结果表明,商陆科植物的心皮发生后,首先形成一个开放的心皮,开口在心皮的腹侧,开口的封闭都是由心皮边缘的:表皮细胞及表皮下的几层细胞的分裂和生长完成。单心皮雌蕊在子房封闭后不留任何痕迹,而多心皮雌蕊的心皮封闭后留下明显的封闭线。封闭线由栅栏组织状组织构成。栅栏组织状组织一直延伸到珠柄,在珠柄基部形成毛刷状结构。离生心皮的隔在子房的生长过程中生长很少,心皮的大部分是分离的;合生心皮的隔在心皮的生长过程中与心皮同步生长,心皮始终是合生的。成熟子房的结构基本相同,子房壁为薄壁细胞,除表皮以外其他细胞均无太:大区别。在子房外侧壁中均匀地分布有3~5个维管束,隔中有一个维管束。胚珠生于子房的基部腹侧。 相似文献
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Eastern Asian endemic seed plant genera and their paleogeographic history throughout the Northern Hemisphere 总被引:1,自引:0,他引:1
We review the fossil history of seed plant genera that are now endemic to eastern Asia. Although the majority of eastern Asian endemic genera have no known fossil record at all, 54 genera, or about 9%, are reliably known from the fossil record. Most of these are woody (with two exceptions), and most are today either broadly East Asian, or more specifically confined to Sino-Japanese subcategory rather than being endemic to the Sino-Himalayan area. Of the "eastern Asian endemic" genera so far known from the fossil record, the majority formerly occurred in Europe and/or North America, indicating that eastern Asia served as a late Tertiary or Quaternary refugium for taxa. Hence, many of these genera may have originated in other parts of the Northern Hemisphere and expanded their ranges across continents and former sea barriers when tectonic and climatic conditions allowed, leading to their arrival in eastern Asia. Although clear evidence for paleoendemism is provided by the gymnosperms Amentotaxus, Cathaya, Cephalotaxus, Cunninghamia, Cryptomeria, Glyptostrobus, Ginkgo, Keteleeria, Metasequoia, Nothotsuga, Pseudolarix, Sciadopitys, and Taiwania, and the angiosperms Cercidiphyllum, Choerospondias, Corylopsis, Craigia, Cyclocarya, Davidia, Dipelta, Decaisnea, Diplopanax, Dipteronia, Emmenopterys, Eucommia, Euscaphis, Hemiptelea, Hovenia, Koelreuteria, Paulownia, Phellodendron, Platycarya, Pteroceltis, Rehderodendron, Sargentodoxa, Schizophragma, Sinomenium, Tapiscia, Tetracentron, Toricellia, Trapella, and Trochodendron, we cannot rule out the possibility that neoendemism plays an important role especially for herbaceous taxa in the present-day flora of Asia, particularly in the Sino-Himalayan region. In addition to reviewing paleobotanical occurrences from the literature, we document newly recognized fossil occurrences that expand the geographic and stratigraphic ranges previously known for Dipelta, Pteroceltis, and Toricellia. 相似文献
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五味子科的系统发育:核糖体DNA ITS区序列证据 总被引:3,自引:0,他引:3
The Schisandraceae is one of the most important taxa for understanding the origin and evolution of primitive angiosperms due to its basal position in the recent cladograms of the angiosperm based both on several gene sequences and on morphological characters, but phylogenetic relationships within the family are still unresolved. The sequences of nrDNA ITS region of 15 species representing four sections of Schisandra Michx., two sections of Kadsura Kaempf. ex Juss. and one outgroup, Illicium fargesii Finet et Gagnep., were used to reconstruct the phylogeny of Schisandraceae. Fourteen most parsimonious trees (Length=259, CI=0.934 and RI=0.889) were obtained from the analysis with I.fargesii as the outgroup. In the consensus tree, the genus Schisandra was found to be divided into three clades. Sect. Pleiostema formed a clade together with sect. Maximowiczia, sect. Sphaerostema was weakly supported to be the sister group of a clade comprising S. bicolor var. tuberculata and Kadsura species. In particular, S. bicolor var. tuberculata, a species of sect. Schisandra, was nested within Kadsura. It seems from this result and the morphological characters that Schisandra might not be a monophyletic group. According to the present molecular phylogeny, both elongated hypocarpium and deciduous habit originated independently at least twice in the Schisandraceae, and therefore, the value of the present morphological characters used in the classification of the family Schisandraceae should be reevaluated. 相似文献
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我国曼陀罗属的花粉形态及其在分类上的意义 总被引:3,自引:0,他引:3
本文收集了国内曼陀罗属(Datura L.) 11个不同的生态型,在光学显微镜和扫描电镜下,进行了花粉粒形态的比较观察。该属花粉粒均为球形或稍扁,具3孔沟型。花粉粒外壁表面的纹饰可作为分属、分组、分种的依据之一。可分为三个类型,与植物形态分类基本一 致,即:具皱波-细网状纹饰(曼陀罗组); 具网状条纹或条纹,条脊表面有细颗粒或粗糙(洋金花组); 具条纹,条脊表面有蚕体状环纹及细颗粒(木本曼陀罗组)。种以下的变种或栽培变种,花粉粒的形态特征不足以作为分类的依据。 相似文献
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报道了中国产12种苔藓植物染色体数目,结果为:壶苞苔Blasia pusilla,n=9;艳
绿光苔Cyathodium smaragdinum,n=9;紫背苔Plagiochasma rupestre,n=9;石地钱Rebou
lia hemisphaerica,n=9;宽片叶苔Riccardia latifrons,n=10;尖叶美喙藓Eurhynchium eustegium,n=11;东亚沼羽藓Helodium sachalinense,n=11;白齿藓Leucodon sciuroides, 相似文献
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