共查询到19条相似文献，搜索用时 437 毫秒
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Five new species of Gesneriaceae from Guangxi of China are described and illus-
trated. They are Oreocharis heterandra , Didymostigma leiophyllum , Chirita macrodonta ,C. macrorhiza and C. liujiangensis. 相似文献
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王印政 《中国科学院研究生院学报》2000,38(3):231-235
对异叶苣苔属植物地上茎形态发生过程的观察旨在揭示该属地上茎的生长式样。该研究发现异
叶苣苔属植物地上茎的生长式样并不是以往所认为的简单顶端生长。该属植物的顶芽已完全受到抑制。其地上茎实际上是萌发于小型叶叶腋的侧芽替代顶芽生长所形成的各级侧枝系统,即合轴分枝系统。异叶苣苔属植物地上茎的不分枝情况是位于大型叶叶腋的腋芽受到抑制所致,纯粹是一种次生现象,并不是尖舌苣苔族植物原始祖先的孑遗性状。尖舌苣苔族其他属植物地上茎的生长式样并不均是从异叶苣苔属植物的生长式样演化而来。出蕊苣苔属和异叶苣苔属植物地上茎的生长式样可能来自同一个不太远的祖先,但已经向着不同的方向演化。独叶苣苔属植物复杂的圆锥状对花聚伞花序并非从异叶苣苔属地上茎上部,即生殖生长部分退化而来,乃幼态成熟的复化过程所致。尖舌苣苔属的总状花序可能更接近尖舌苣苔族的原始祖先类型。 相似文献
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报道了在广西发现的苦苣苔科异裂苣苔属一新变种，即粉绿异裂苣苔Pseudochirita guangxiensis (S. Z. Huang) W. T. Wang var. glauca Y. G. Wei & Yan Liu。它与原变种的区别在于叶近全缘或有不明显的钝锯齿，茎和叶背、叶面密被近贴伏的绒毛，花冠外疏被腺毛。 相似文献
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本文首次报道了中国特有异叶苣苔属的染色体数目及核型。该属所研究种类的染色体数目均为
2n＝18,染色体长度在2.0µm以上,在尖舌苣苔族所报道的染色体中显示出较原始的性状。尖舌苣苔
族的染色体基数可能是x=9。异叶苣苔属的间期核均为复杂型;前期染色体呈渐变型。核型从对称型
向不对称型的演化主要表现在近中部着丝粒,尤其是近端部着丝粒染色体比例的增大。毕节异叶苣苔
W．bljieensis和峨眉异叶苣苔W．tsiangiana var．wilsonii的核型分别为2n=2m＋8m＋8sm(1sat)和
2n=2m＋8m(1sat)＋8sm(2sat),较为对称。紫红异叶苣苔W．purpurascens和白花异叶苣苔W.
tsiangiana var. tsiangiana的核型分别为2n=4m＋6sm＋8st(1sat)和2n=4m＋8sm(2sat)＋6st,比较
特化。河口异叶苣苔W．hekouensis的核型是2n=4m+10sm(1sat)+4st,处于二者之间。峨眉异叶苣
苔和原变种白花异叶苣苔的核型差异较大,在外部形态方面二者之间的性状变异也间断较大。本文建 议将该变种从白花异叶苣苔W．tsiangiana中移出自成一种,并和毕节异叶苣苔近缘。 相似文献
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潘开玉 《中国科学院研究生院学报》1988,26(6):450-457
Ten new species, three new varieties and a new section of the family Ge-
sneriaceae are described from China in the present paper. They are Tremacron urceolatum
K. Y. Pan from Muli of SW Sichuan, T. obliquifolium K. Y. Pan from Miyi and Yanyuan
of SW Sichuan, T. aurantiacum K. Y. Pan from Mabian and Pinshan of S Sichuan, lsometrum
Sect. Chorianthera W. T. Wang et K. Y. Pan (with I. eximium Chun as the section type),
Isometrum eximium Chun ex K. Y. Pan from Jiulong, Muli and Jinyang of SW Sichuan;
Ancylostemon mairei (Levl.) Craib var. emeiensis K. Y. Pan from Mt. Emei of Sichuan, A.
aureus (Franch.) Burtt var. angustifolius K. Y. Pan from Zhenkang of SW Yunnan, A. ga-
mosepalus K. Y. Pan from Hanyuan, Yanyuan and Yuexi of SW Sichuan, A. rhombifolius K.
Y. Pan from Meigu of SW Sichuan, A. ronganensis K. Y. Pan from Rong an of Guangxi;
Corallodiscus flabellatus) (Craib) Burtt var. puberulus K.Y. Pan from Zhongdian and Deqin
of NW Yunnan, Nanchuan of S Sichuan and Zayü of Xizang (Tibet), Beccarinda minima
K. Y. Pan from Jinxiu and Xiangzhou of Guangxi, Boeica stolonifera K. Y. Pan from Fang-
cheng, Shiwandashan, Pingnan and Dongxing of S Guangxi, B. multinervia K. Y. Pan from
Yingjiang of W Yunnan, and Paraboea barbatipes K. Y. Pan from Napo of W Guangxi and
Xichou of SE Yunnan. 相似文献
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韦毅刚 《中国科学院研究生院学报》2004,42(6):528-532
报道了在中国广西发现的苦苣苔科一新属即方鼎苣苔属Paralagarosolen Y. G. Wei 和一新种方鼎苣苔P. fangianum Y. G. Wei。方鼎苣苔属与细筒苣苔属Lagarosolen W. T. Wang近缘，它们的共同特征是花筒细筒状，不肿胀，柱头2；不同点是方鼎苣苔属叶基部有时盾状，聚伞花序具1朵花，花冠裂片顶端圆钝，蒴果宽卵状椭圆球形。 相似文献
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描述了在广西发现的苦苣苔科一新属和一新种，即文采苣苔属Wentsaiboea D. Fang & D. H. Qin及文采苣苔W. renifolia D. Fang & D. H. Qin, 并提供墨线图。文采苣苔属的柱头外形略似长檐苣苔属Dolicholoma D. Fang & W. T. Wang, 不同在于前者叶肾形，基部心形，具掌状脉，花冠斜钟状，裂片圆形，雄蕊和退化雄蕊着生于冠筒近基部。新属在体态上还接近小花苣苔属Chiritopsis W. T. Wang, 但前者叶具掌状脉，冠筒钟状，远轴侧膨胀，柱头马蹄形；在后者叶具羽状脉，冠筒筒状，不膨胀，柱头下唇倒梯形至线形。 相似文献
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《中国科学院院刊(英文版)》2012,26(3):194-195
According to an announcement released by the US National Academy of Sciences (NAS) on May 1, 2012,two outstanding scientists from China including physicist ZHANG Jie and chemist Vivian Wing Wah Yam, both 相似文献
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史蒂芬·霍金 (S .W .Hawking)是 2 0世纪具有很强国际声誉的理论物理学家之一 ,这位伟人在科学理论的认识上具有独到的见解 :对物理理论持典型的朴素证伪主义的观点 ;在物理学统一上 ,谨慎而乐观地相信存在一种完整的统一理论 ;而且 ,“实在”在某种意义上以理论为前提。 相似文献
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本文为独叶草形态学研究的一部分,主要报道其根状茎结构的初步观察结果。根状茎的初
生结构的基本图案类似一般多年生草本植物的根状茎。但其维管束连接成简状,缺乏髓射线,
以后产生的次生维管组织中亦缺乏明显的射线。木质部的导管主要为梯纹加厚。梯纹导管的分
子的穿孔板呈水平的和不同程度的倾斜状的,水平的和一部分倾斜状的穿孔板上只具有单个
大穿孔,而另一些倾斜状的穿孔板上,呈一种复穿孔到单穿孔的过渡形式。参照Bailey(1956)
指出的管状分子的演化是不可逆的观点,联系到毛茛科植物一般具有单穿孔的导管,应属于一种原始的结构特征。独叶草的营养叶,鳞片叶和芽苞叶都具有单叶隙,前者具四个叶迹,后两
者都具有一个双重性的叶迹。参照前人的看法,联系独叶草的叶,花和导管分子中的一些原始性状推测,可能如Foster(1960,1961)曾指出的,在三叶隙和多叶隙占多数的毛莨科中,独叶草的单叶隙可能是一种原始的形态。 相似文献
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The present paper is an attempt to throw some light on two Composite genera,
Cavea W. W. Smith et Small and Nannoglottis Maxim., of which the generic features
and the systematic position were heretofore rather badly known.
Cavea, a monotypic genus based upon Saussurea salwinensis Drumm., was described
by W. W. Smith and Small as monocious. From the ample material now in our com-
mand, it is found that the genus is either monocious and dioecious, the capitula in the
latter case being homogamous. The individuals exclusively provided with sterile flowers
are usually smaller in size, sometimes even stemless. Such repartition of sexes was
known in the subtribe Plucheinae (tribe Inuleae), to which W. W. Smith and Small were
correct to ascribe their genus.
Nannoglottis was considered by Maximovicz as un abnormal genus of the tribe
Inuleae, having heterogamous capitula with one series of peripheric fertile ligulate pistil-
late flowers. Having examined the type specimen of N. carpesioices Maxim. and the ex-
tensive collection from Kansu and Tsinghai, we incline to say that the genetic characters
as discerned by Maximovicz are doubtlessly due to his inaccurate observation. The
flowers of Nannoglottis are in fact trimorphous, of which the pistillate ones are 2-3-
seriate, the outer being shortly ligulate and the inner, short-tubulate with truncate apex.
Handel-Mazzetti, much later, indicated that, in another species, the pistillate flowers are
2-3-seriate, but no mention was made about the inner tubulate pistillate flowers.
Franchet, appearing to be unware of Maximovicz's genus, founded his Stereosanthus
Franch. and considered it as a genus intermediate between the tribes Inuleae and Sene-
cioneae. The genus was misinterpreted by Franchet as having dimorphous flowers, the
pistillate ones being all ligulate. Curious enough, one of the major generic features, viz.,
the presence of inner tubulate pistillate flowers, was neglected by all early botanists and
was first recognized by Handel-Mazzetti fourty years later.
However, Handel-Mazzetti was still unacquainted with the characters of Nannoglot-
tis and proposed therefore his new genus Vierhapperia Hand.-Mzt. on the reason that the
flowers are trimorphous. Moreover, he compared his genus with Conyza L. and Erigeron
L. of the tribe Astereae, but the characters marked by him appear not to be different
from those of Nannoglottis.
From the above morphological comparaison, it is evident that Nannoglottis and two
other genera in question possess in common important characters in the general appea-
rance, the flower-forms and the structure of achenes and pappus. The differences in the
disposition of involucral bracts and the length of ligules are criteria good for separating
species, but can hardly be regarded as sufficient for generic delimitation. Moreover,
these three genera are almost similar in their geographical distribution. These points are
adequate to warrant that Stereosanthus and Vierhapperia are in reality congeneric with
Nannoglottis.
Nannoglottis appears to have been correctly placed by Hoffmann in the subtribe
Senecioninae (tribe Senecioneae) though in that subtribe it finds no close relatives. On
account of the outstanding characters of the genus, a further study of its systematic posi-
tion is required.
The present paper is brought to close by a tentative scheme of classification of the
genus so amplified, of which two sections, namely, sect. Stenolepis Ling et Y. L. Chen
(Stereosanthus Franch., p. p. min.) and sect. Nannoglottis (Stereosanthus Franch., p. p.maxim.; Vierhapperia Hand.-Mzt.), altogether including 9 species, are being proposed. 相似文献
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发现卧龙乌头Aconitum wolongense W．T. Wang的模式实际上包含两种植物，即毛果甘青乌头A．
tanguticum (Maxim．)Stapf．var．trichocarpum Hand.-Mazz．和展毛大渡乌头A．franchetii Fin.et Gagnep．var．villosum W．T. Wang，故将该种予以归并。 相似文献
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奇点问题是以广义相对论为基本理论框架的现代宇宙学所面临的自身无法克服的重大疑难问题。霍金的虚时间的数学处理方法可以避免奇点的出现，并很可能使描述极早期宇宙的量子效应与描述整个宇宙演化的广义相对论效应协调。本文从霍金时间概念的变革、虚时间的物理意义和哲学意义三方面研讨了虚时间问题，并提了一些作者独到的新见解。 相似文献
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根据对新宁楼梯草Elatostema xinningense W.T.Wang模式标本的研究，结合在新宁楼梯草模式产地湖南省新宁县紫云山的野外调查，将新宁楼梯草降级并组合为对叶楼梯草E.sinense H.Schr⒐ter的变种。 相似文献