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1.
中国兜被兰属植物的花粉形态及其分类意义   总被引:2,自引:0,他引:2  
兜被兰属Neottianthe全世界共约12种,中国均有分布,其中9种为我国所特有。本属花粉形态 和组成都很特殊,它是由许多单粒花粉粘结在一起形成复合花粉——花粉小块,其形状一般为狭长的三 棱锥体形。外壁表面具5种纹饰类型:(A)近光滑,或具十分微弱的小凹陷;(B)外壁具穿孔状纹饰; (c)外壁具沟渠状纹饰;(D)外壁具拟网状纹饰;(E)具典型的网状纹饰。奉属有些种类,例如:N.cal- cicola,N.monophylla,N.pseudo-diphylax和N.cucullata等4种在分类上还存在许多问题,有些分类 学家把N.calcicola,N.monophylla,N.pseudo-diphylax 3种均归并于N.cucullata。孢粉学资料表 明上述4个种花粉特征完全不同,因此,上述4种仍应各自独立为种。最后,强调指出N.camptoceras的花粉形状和外壁纹饰等特征在本属为特殊类型。  相似文献   

2.
Eucharis, Caliphruria, and Urceolina form a monophyletic group of petiolate-leaved, Neotropical Amaryllidaceae ecologically specialized to the understory of primary tropical rain forest below 2,000 m elevation. Pollen morphology of the three genera is surveyed. Pollen grains of all species of Eucharis, Caliphruria, and Urceolina are boat-shaped elliptic, monosulcate, heteropolar, and bilateral in symmetry. Exine sculpturing is semitectate-columellate and reticulate in all species examined. A transformation series in reticulum coarseness and pollen grain size is described. The large pollen grain with coarse reticulum of most Eucharis species is considered ancestral. The fine reticulation of Caliphruria is considered derived and the exine morphology of Urceolina is intermediate. Both of these genera have medium-sized pollen grains. Exine dimorphism common to all Urceolina, but rare in Eucharis and Caliphruria, may be symplesiomorphous among those taxa exhibiting this morphology. The three genera are largely uniform in pollen grain ultrastructure, with completely ektexinous exines. Pollen grain size in Eucharis is not closely correlated with style length. Several wide-ranging species show considerable intraspecific variation in pollen size. Parallelisms in pollen grain evolution among related tribes of Neotropical Amaryllidaceae are discussed.  相似文献   

3.
Pollen of 53 species of Dilleniaceae and Actinidiaceae was examined by light microscopy, scanning electron microscopy, and a selected group in transmission electron microscopy. Dilleniaceae pollen ranges from tricolpate, tricolporate, tetracolpate, and incipiently inaperturate. Tricolpate types occur only among the Old World subfamily Dillenioideae and the compound aperturate (3-colporate) condition is restricted to the subfamily Tetraceroideae. Within the Dilleniaceae the tricolpate pollen type with elongated apertures is considered primitive, having given rise to the 3-colporate and 4-colpate conditions. The striking pollen dimorphism in the Neotropical species of Tetracera, all of which are androdioecious, is documented; however, in contrast to previous reports, pollen from bisexual flowers appears to be incipiently inaperturate and not pantoporate. The inaperturate condition is interpretated as an early stage in the evolution of outcrossing. Pollen morphology does not support a close relationship between Dilleniaceae and Actinidiaceae. Pollen morphological differences that can be noted between these families are: tectum complete and predominantly psilate or psilate-granular in Actinidiaceae, tectum incomplete, punctate to reticulate in Dilleniaceae; an equatorial bridge of ektexine over the endoaperture usually present in Actinidiaceae, absent in Dilleniaceae; columellae reduced in Actinidiaceae, columellae usually well-developed in Dilleniaceae. Pollen morphology does not argue against a close relationship between Actinidiaceae and Theaceae.  相似文献   

4.
芒苞草属的群落学特征和花粉形态   总被引:3,自引:1,他引:3  
本研究表明芒苞草(Acanthochlamys bracteata)的花粉形态与石蒜科、鸢尾科完全不同。经请教吴征镒教授,他在来信中认为芒苞草应“属于在中国(乃至东亚)未曾记录过的一个老科——翡若翠科Velloziaceae”,横断山区一个可能是特有的单种属,分布在干旱河谷灌丛、稀疏针叶林以及亚高山嵩草草甸中。  相似文献   

5.
Drugg , Warren S. (California Res. Corp., La Habra.) Pollen morphology of the Lennoaceae. Amer. Jour. Bot. 49(10): 1027–1032. Illus. 1962.—The family Lennoaceae contains 3 genera: Pholisma, Lennoa, and Ammobroma. The pollen of Pholisma is 4-colporate with less common 3- and 5-colporate grains. Lennoa pollen is 3-colporate with rare 4-colporate examples. All Ammobroma pollen is 3-colporate. Pollen of both Lennoa and Ammobroma exhibits sexine thinning in the mesocolpia with resultant depressions. This feature is lacking in Pholisma. Sculpture is reticulate-simplibaculate on pollen of Lennoa and Pholisma, and reticulate-duplibaculate on pollen of Ammobroma. Pollen morphology supports placement of Lennoaceae in the Polemoniales near the Boraginaceae and Hydrophyllaceae.  相似文献   

6.
泽泻科的花粉形态研究   总被引:5,自引:0,他引:5  
本文对泽泻科11属27种代表植物的花粉进行了光学显微镜、扫描电镜和透射电镜观察。在系统描述了该科及各属植物花粉形态的基础上,将泽泻科植物的花粉划分为3种类型,即少果泽苔草型、慈菇型和泽泻型。根据花粉形态特征的比较,并依据泽泻科植物祖先类群的花粉具有船形、具单沟萌发孔、花粉外壁具明显的刺状纹饰、覆盖层完整无通道等特征,作者认为泽泻科植物花粉形态的如下演化趋势是明显的:由船形演化为卵球形、球形和多面体球形;由单沟萌发孔经过一无孔的中间类型演化为散孔类型;孔膜由光滑演化为具颗粒和小刺;萌发孔不内陷进化到内陷;花粉粒外壁的刺状纹饰逐渐过渡为颗粒状纹饰或者消失,以及覆盖层由无通道到具细通道和通道。  相似文献   

7.
Tilosomes, also called “fibrous bodies” or “rod bodies” in older literature, are lignified excrescences from the walls of cells of the innermost velamen cell layer adjacent to thin-walled passage cells of the exodermis in roots of many epiphytic orchids. Seven broad morphological types are recognized: spongy, lamellate, discoid, webbed, meshed, baculate, and plaited. Some types characterize specific genera or subtribes of Orchidaceae. Of the 350 species in 175 genera included in a survey of the family, tilosomes occur in 95 species and 39 genera and are concentrated in tribe Polystachyeae and subtribes Sobraliinae, Coelogyninae, Laeliinae, Pleurothallidinae, Bulbophyllinae, Lycastinae, and Maxillariinae. With the exception of the pantropical genera Bulbophyllum and Polystachya and the Paleotropical subtribe Coelogyninae, tilosomes are almost exclusively Neotropical phenomena.  相似文献   

8.
The pollen of all four genera of Gronovioideae—Cevallia, Fuertesia, Gronovia, and Petalonyx—was examined in light microscopy, and scanning and transmission electron microscopy. The pollen of Cevallia, of Fuertesia, and of Gronovia can be easily distinguished from each other and from all remaining Loasaceae. Only Petalonyx, with a striate tectum, shows a clear relationship to the Mentzelioideae and Loasoideae, the vast majority of which have striate-reticulate or striate tecta. The trichome data are mostly congruent with the pollen data: Cevallia, Fuertesia, and Gronovia each have a distinctive trichome not known to occur elsewhere in the family, while Petalonyx has only the common types. A cladistic analysis of Gronovioideae utilizing Mentzelia as the outgroup proposes that Cevallia, Gronovia, and Fuertesia are a sister group to Petalonyx within the subfamily. The relationships of the four genera to each other and of Gronovioideae to the Loasaceae are discussed.  相似文献   

9.
Pollen of the scrophulariaceous genera Melosperma and Monttea was studied with light and scanning electron microscopy. Both have single, radiosymmetric, isopolar, trizoniaperturate pollen grains with usually ruptured colpus membranes, tectate-perforate to semitectate exines with a columellate interstitium and pitted or perforate nexines. Intergeneric differences in pollen morphology are established based on the differential correlation of sculpturing characters. Comparisons of the pollen of Melosperma and Monttea with that of the tribe Minuleae sensu stricto reveals no difference in the case of Melosperma and the existence of intermediate morphologies and “reticulate” similarities in the case of Monttea; the taxonomic significance of this morphological intergradation is considered. The transfer of Oxycladus aphyllus to Monttea is consistent with the pollen evidence, but proposed affinities between Monttea and tribe Antonieae of the Loganiaceae are not supported.  相似文献   

10.
Pollen of 48 species of Schefflera was studied by light and scanning electron microscopy. Eight pollen types are distinguished on the basis of sexine sculpturing and structure, apertural shape, and shape and size of the grains. These pollen types correlate well with other data such as the number of carpels, the condition of corolla, infloresence types, and geographical distribution of each species. To determine the evolutionary status of sexine structure, an association between sexine characters and the number of carpels was sought. Assuming polymery of floral parts to be a primitive condition in Araliaceae, the undifferentiated sexine, which occurs in the multicarpellate species, also appears to be primitive. Other unspecialized features include short grains, and non-sculptured, imperforate tectum. Several species in New Guinea and the Solomon Islands belong to this putative ancestral pollen type, from which other types may have been derived.  相似文献   

11.
山茶属的花粉形态及其分类学意义   总被引:6,自引:3,他引:6  
本文对山茶属(Camellia L.)18个组27个代表种的花粉进行了光学显微镜、扫描电镜和大部分进行了透射电镜的观察,并对花粉大小、形状、外壁纹饰和超微结构等作了综合的比较。结果表明,其形状和大小差异不很明显。花粉壁的层次、厚度和不同层次的比例,如复盖层与柱状层以及外壁外层与外壁内层的比例等也没有显著的差异。但花粉壁的纹饰特征在扫描电镜下显示出较大的差异,具有较重要的分类学价值。根据其纹饰特征,可以把山茶属花粉大致区分为六个类型:皱疣状纹饰;粗瘤状纹饰;颗粒状至皱-颗粒状纹饰;穴-网状纹饰;皱沟状纹饰及皱波-念珠状纹饰。孢粉学上区分的类型不完全与各个学者从植物形态上划分的组相一致。其中管蕊茶 Camellia lanceolata的纹饰非常特殊(粗瘤状),其外壁表面很象牛心果(Annona reticulata)的外形特征,为其重新分类提供孢粉学依据。  相似文献   

12.
中国沙拐枣属花粉形态的研究   总被引:2,自引:0,他引:2  
  相似文献   

13.
须芒草族植物花粉形态的观察   总被引:1,自引:1,他引:1  
在光学显微镜下和扫描电镜下对禾本科须芒草族(Andropogoneae)中分隶于8个亚族34个属的36种植物的花粉进行形态面容和比较研究。结果显示,本族植物花粉形态较为一致,花粉近形或扁球形,单萌发孔,孔,周围加厚,具盖,外壁表面散布有颗粒。这表明其是一个自然类群。总体来讲,芬烨大的演化分异,只是表面纹饰的和芬烨大小有一;定的差异。纹饰可分为三种类型粗糙型,不明显疠状突起才明显疠状突起型。花粉开矿  相似文献   

14.
Pollen morphology of 15 species of Siphonoglossa and of two closely related groups was investigated. Two tribal-specific pollen types are found within Siphonoglossa sensu lato suggesting that the genus is artificial, composed of taxa belonging in several genera among two tribes (subtribes sensu Bremekamp) of Acanthaceae. Five taxa currently included in an informal subgeneric category of Siphonoglossa have tricolporate, prolate pollen (termed Type I) that is characteristic of Odontonemeae (= Odontoneminae, Justicieae). Pollen of the remaining taxa, belonging in two formal sections of the genus, are mostly 2-porate, bilateral (Type II) with a sexine sculpturing characteristic of Justicieae (= Justiciinae). Pollen of section Siphonoglossa is rather uniform, 2-porate, bilateral with lolongate pores, and seem to delimit a natural group. Taxa of section Pentaloba have a more heterogeneous pollen morphology, mostly 2-porate, bilateral with lalongate pores. Controversial aspects of the interpretation of pollen morphology in Justiciinae are presented and their relevance to this study are examined. Hypothetical trends in the evolution of pollen of Justiciinae are discussed and the application of pollen morphology to taxonomy of the genus is presented, including a recommendation for narrowing the generic concept of Siphonoglossa to the taxa of the type section.  相似文献   

15.
马尾树科及其近缘科花粉形态研究   总被引:1,自引:0,他引:1  
本文观察了马尾树科(Rhoipteleaceae)、胡桃科(Juglandaceae)以及桦木科(Be-tulaceae)、9属9种植物花粉形态。马尾树科与桦木科桦木属(Betula L.)花粉粒均为扁球形,极面观呈钝三角形,萌发孔类型均为多孔类型,孔之间均有弓形加厚,而且外表面均具细颗粒状雕纹。而胡桃科大多为多边形、散孔类型。根据花粉形态资料,探讨了马尾树科的系统位置。  相似文献   

16.
伯乐树科及其近缘科的花粉形态研究   总被引:5,自引:0,他引:5  
本文观察了伯乐树科、省沽油科、牛栓藤科、七叶树科、无患子科、罂粟科,共6科、17属、21种植物的花粉形态。依据花粉资料,探讨了伯乐树科的系统位置。认为伯乐树科与无患子目中牛栓藤科关系较为密切。牛栓藤科较为进化,伯乐树科较为原始。与无患子目中其他一些科关系不明显。伯乐树科与罂粟科、豆科中云实亚科的花粉形态有某些相似,而伯乐树科较为进化。与辣木科、白花菜科花粉形态较少相似。  相似文献   

17.
Of all species comprising the two genera of the Cabombaceae, only Brasenia schreberi J. F. Gmel. and Cabomba caroliniana Gray have been critically investigated with regard to their pollination biology. Brasenia schreberi has been shown to be anemophilous, while C. caroliniana has an entomophilous (myophilous) pollination syndrome. In the present paper, a number of pollen and pollen-related characters, including pollen size, shape, quantity, terminal settling velocity, pollen-ovule ratios, and overall exine architecture of B. schreberi and C. caroliniana are evaluated. Pollen from both species is elliptic, monosulcate, and has a tectate-columellate sporoderm with supratectal surface ornamentation. Grains of B. schreberi are small, produced in copious amounts, and settle relatively slowly. Flowers of this species have large pollen-ovule ratios. The exine of B. schreberi pollen is scabrate, relatively thin, has a uniformly thick sexine composed of a two-zoned (homogeneous/granular) tectum and distinct columellae, and a homogeneous nexine. Pollen of C. caroliniana is relatively large, produced in small quantities, and has a rapid terminal settling velocity. Flowers exhibit small pollen-ovule ratios. Exine organization of C. caroliniana pollen is typically two times thicker than that of B. schreberi; ornamentation is striate. Nonapertural sexine regions have a thick tectum and well-defined columellae, with both sexine components traversed by a dense system of channels. The nexine is relatively thin. All of the palynological characters examined correlate well with the anemophilous and entomophilous syndromes of B. schreberi and C. caroliniana, respectively. Moreover, several other parameters of exine ultrastructure from each species exhibit positive correlations with the respective pollination mechanisms, including: tectum thickness, columellae diameter, tectum-nexine ratios, and the consistency, distribution, and total amount of pollenkitt present. Overall exine ultrastructure is also discussed from a historical perspective as well as with respect to its phylogenetic significance.  相似文献   

18.
乌云伞的解剖学及花粉形态学研究   总被引:3,自引:0,他引:3  
八角莲属(Dysosma)是小檗科(Berberidaceae)一个重要属,全国共有7个种,大约分布于北纬23—32°,东经94—122°之间。湖北八角莲属有4个种,其中乌云伞(Dysosma lichuanensis Z. Cheng, sp. nev., ined.)为内定种,是多年生草本,它的形态特征与八角莲(Dysosma  相似文献   

19.
席以珍 《植物研究》1987,7(2):17-26
本文用光学显微镜和扫描电子显微镜系统观察了苦苣苔科后蕊苣苔属的花粉形态,本属花粉粒为近球形,稍长或稍扁,具三拟孔沟,个别种具四拟孔沟的萌发孔类型,外壁表面具网状纹饰,网脊光滑或具小刺。根据网脊宽度。网眼形状以及网纹明显程度而将本属花粉分为三个类群.1.网脊较宽,宽度不均匀,网脊宽度大于网眼直径,包括的植物种类有Opithandra sinohenryi,O.primoloidesO.fargesii等三种;2.网脊较窄,宽度均匀,包括的种类是O.dalzielii,O.obtusidentata,O.dinghushnnensisO.cinerea等4种;3.网不明显,小刺突出,具这种纹饰的植物只有O.acaulis一种。  相似文献   

20.
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