Seed Morphology of Impatiens L. (Balsaminaceae) and Its Taxonomic Significance

The seed surface of 12 species of Impatiens L. from Mt. Omei was observed under SEM for the first time. The important characters used in the paper include cell specialization on seed surface, arrangement pattern of the cells, the degree of the cell elevation, chalazal zone morphology and appendix at the tail of the seed. According to these characters, the seed surface morphology of 12 species can be divided into two types: 1. the seed without conspicuous differentiation of surface cells, laevigate on the surface, represented by I. wilsoni; the seeds of species indicated by 3-colpate pollen grains are expected to belong to the type. 2. the seed with the large cell elevation at different levels, surface scabrous, represented by the other 11 species; most species with 4-colpate pollen have this kind of seeds. The results verify that the seed morphology of the genus can supply characters significant to taxonomy of the genus at species level. The evolution of seed surface of Impatiens has close correlation with that ofthe flower and pollen morphology.     

中国大蒜芥族植物花粉形态的研究

对中国大蒜芥族10属14种植物花粉形态分别进行了光镜和扫描电镜下的观察研究。结果表明该族花粉形态可划分为4种类型：（1）具3沟,超长球形,网状纹饰,外壁2层;（2）具3沟,超长球形,细网状纹饰,外壁1层;（3）具3沟（偶4沟）,长球形,网状纹饰,外壁2层;（4）具6沟,长球形,网状纹饰,外壁2层。因此,中国大蒜芥族的花粉形态多样性程度较高,说明了它不是一个自然类群,是一个多系类群,这与前人研究结果相一致。另外,本文首次报道十字花科锥果芥属植物具6沟花粉,具6沟花粉在十字花科中极为特殊,所以作者将锥果芥属提升为族级,另立新族,即锥果芥族（Tribe Berteroelleae F．Z．Li,G．Y．Tang ＆ Z．Y．Sun,trib．nov．）。     

凤仙花属总状花序组的花粉形态及其分类学意义

总状花序组隶属于凤仙花亚属凤仙花属,以具多花的总状花序、侧生萼片2枚、子房5室、果实为线状圆柱形、种子多数、迈卵形、种皮表面具指状突起等特征区别于该亚属的其他类群。前人对凤仙花花粉形态的研究表明凤仙花属的花粉形态对于属下分类及种间界定具有重要的分类学价值。而对于总状花序组来说,有关花粉形态方面的研究少有报道,为了进一步探讨该组花粉S的形态特征及其分类学意义,该研究应用扫描电镜技术对总状花序组的21种植物的花粉进行了观察。结果表明:总状花序组植物的花粉粒均具4条萌发沟,两侧对称,极面观为矩圆形、长矩圆形或近方形;长赤道面观多为椭圆形至矩圆形,短赤道面观为椭圆形;长、短赤道轴比值多在1.4~2.4范围内;表面具网状纹饰,网眼在花粉粒表面均匀分布或赤道面的网眼较极面观的小,网脊边缘光滑或具波状突起,网眼内具不同密度的颗粒状突起。该组的花粉形态与宏观形态性状相关性较小,但花粉极面观形状、长短赤道轴的比值、网眼的分布、网脊边缘形状、网眼内颗粒物密度等特征具有种水平上的稳定性和特异性,对该组植物种间界定具有重要的意义。     

Studies on the Pollen Morphology of the Genus Brassica (Cruciferae) in China

The present paper reports the pollen morphology of 36 species and varieties of Brassica L. in China mostly for the first time. They were examined both under LM and SEM. Pollen grains of Brassica L. in China are long-spheroidal, subspheroidal, spheriodal, oblate, rarely reniformis or subsquare. According to the aperture characters pollen grains may be divided into four types: 2,3,4-colpate, 3-colpate, 3,4-colpate, 3,4-colporate. The exine sculpture may also be divided into three types: 1, reticulate, 2, cerebroid-reticulate, 3, foveolatereticulate. Detailed characters of pollen grains for each taxon are presented in Table 1. The 2,3,4-colpate type of pollen grains may be considered as primitive one and the 3,4-colpate or 3,4-colporate type of pollen grains is the most advanced in Brassica. The tricolpate aperture and reticulate exine have been reported by the previous authors, whereas, 3,4-colporate and cerebroid-reticulate or foveolate-reticulate pollen grains are newly reported.     

Pollen morphology of endemic species of the Horton Plains National Park,Sri Lanka

The pollen morphology of 27 endemic and palaeoecologically-important species belonging to 16 families and 20 genera from the mountain rain forests of Sri Lanka was studied using both light (LM) and scanning electron microscopy (SEM). The pollen grains exhibit a wide range of morphological characters. Their sizes (P and E) are in the range 10-53 2 9-60 mum, and they are distributed among seven shape classes. All the taxa have radially-symmetrical pollen grains except for Impatiens (bilateral). The amb varies from rounded to triangular, with intermediate shapes possible. The pollen grains of all the Lauraceae species studied are inaperturate and microspinose, with a thin, fragile, perforated exine. Sarcococca zeylanica (Buxaceae) has pantoporate pollen grains and a Croton -pattern consisting of faintly striate pegs of various shapes attached or enveloping the smooth rings. Colp(or)ate, syncolpate to parasyncolp(or)ate pollen grains with rugulate to perforate exine patterns occur in Eugenia mabaeoides ssp. mabaeoides and Syzygium ssp. (Myrtaceae). Osbeckia walkeri (Melastomataceae) has heterocolpate pollen with fossulate, foveolate to perforate exine pattern. 3-colporate, microreticulate pollen grains are met with in Euonymus revolutus (Celastraceae), and scabrate-microreticulate ones in Calophyllum walkeri (Clusiaceae). Hedyotis lawsoniae (Rubiaceae) pollen is microreticulate to perforate, while pollen of the Elaeocarpus (Elaeocarpaceae) species is 3-colporate, smooth to scabrate-perforate. Casearia thwaitesii (Flacourtiaceae) has 3-colporoidate pollen grains with a smooth, imperforate to occasionally sparsely perforate exine. Mastixia spp (Cornaceae) have a granular-perforate exine pattern, while Adinandra lasiopetala (Theaceae) has a smooth-perforate exine pattern. Triangular 3 (4)-colporate, and indistinctly faintly microreticulate-perforate pollen was found in Rhamnus arnottianus (Rhamnaceae), rugulate-perforate in Isonandra montana (Sapotaceae) and verrucate-perforate in Symplocos elegans (Symplocaceae). Glochidion coriaceum (Euphorbiaceae) has a 5-colporate grain with a coarsely reticulate exine pattern. Pollen grains of Impatiens walkeri and I. thwaitesii (Balsaminaceae) are bilateral, 4-colpate, reticulate and granular. A pollen key based on light microscope is constructed for all the taxa studied.     

Pollen Morphology of Plumbaginaceae in China

The present paper describes the pollen morphology of 30 species belonging to 7 genera of Plumbaginaceae from China. The pollen grains were all examined under light microscope, and those of some species under scanning and transmission electron microscope. The pollen grains of the family are subspheroidal, prolate or oblate, (37.5-74.5)× (40.4-81.9)μ in size, 3-colpate, rarely 4-6-colpate, only pancolpate in Ceratostigma willmottianum. The exine 2-layered, 2.0-7.4μ thick, sexine thicker than nexine, verrucate, reticulate or coarsely reticulate. On the basis of the morphology, two types of pollen grains are distinguished in the family: (1) The pollen grains are 3-(rarely 4-6 ) or pancolpate, the exine verrucate. They are found in the tribe Plumbagineae (inculuding the genera Ceratostigma, Plumbago and Plumbagella). (2) The pollen grains are all 3-colpate, the exine reticulate or coarsely reticulate. They are found in the tribe Staticeae (including the genera Acantholimon, Ikonnikovia, Goniolimon and Limonium ).     

A Study on the Pollen Morphology in Trochodendron,Tetracentron and Euptelea

Trochodendron, Tetracentron and Euptelea are considered as a small group of the primitive angiosperms. They are endemic to or mainly distributed in China. Their systematic position has long been debated. The purpose of the present work is to present palynological data both for systematic discussion and for the identification of fossil pollen. The three genera share a number of pollen characters, for example, being spheroid in shape, exine surface distinctly reticulate and lumina rather small and irregular in shape, etc. They are, however, obviously different in other respects of pollen morphology. The pollen grains of Euptelea are the largest of three (c. 30 μm in diameter), those of Tetracentron, the smallest (c. 15) and those of Trochodendron, intermediate (c. 20), 3-colpate in Trochodendron and Tetracentron, and those in Euptelea are 3-celpate but with transitional apertures in one species and 6-rugate, not 3-colpate, in the other. The ruga membranes are coarsely granular (rod-shaped elements under SEM). The lumina are the smallest in Euptelea. Muri in Tetracentron are distinctly striate. Thus, the establishment of three separate families is supported by pollen morphology. Since the pollen grains of Trochodendron and Tetracentron are 3-colpate and those of Magnoliaceae are 1-sulcate, it seems unreasonable to refer them to Magnoliaceae (or Magnoliales). If the rugae of pollen grains in Euptelea further shortened and their number increased, they would resemble those of Hamamelidaceae (such as Sycopsis). Pollen morphology, therefore, suggests that Euptelea is related to Hamamelidales, and supports Cronquist’s viewpoint. Hutchinson (1969) includes both Trochodendron and Euptelea in the same family (Trochodendraceae). However, these two genera are rather distinct in morphology and structure, the presence or absence of vessels and chromosome number, etc. Pollen morphology of two genera also disagrees with the Hutchinson’s viewpoint.     

Studies on Pollen Morphology of the Genus Corylopsis

The present paper describes the pollen morphology of 11 species of thc genus Corylopsis (Hamamelidaceae). The pollen grains were all examined with light microscope and scanning electron microscope. Pollen grains of the genus are prolate, spheroidal or subprolate. Three size types are recognized: (l) 18-23 μm, found in Corylopsis omeiensis Yang, C.gotoana Makino, C. himalayana Griff and C.platypetala Rehd. et Wils. (2) 24-32μm, found in C. sinensis Hemsl., C.willmottiae Rehd. et Wils., C.veitchiana Bean, C. brevistyla H.T.Chang, C.multiflora Hance, C.pauciflora Sieb. et Zucc. and C.spicata Sieb. Zucc. (3) 34-39μm, found in C. wilsonii Hemsl. and C. cordata Merrill. Pollen grains are 3-colpate and 4-colpate (only infrequently found in Corylopsis sinensis Hemsl.); the exine is 2-layered, 1.25-2.50μm thick, distinctly reticulate, sexine almost equal to nexine in thickness. From the pollen morphology the genus is considered as a natu-ral group.     

芥蓝与芸苔属几个常见种花粉形态的比较

本文通过对芸苔属(Brassica L.)几个常见种芥蓝(B. alboglabra Bailey)、芥菜(B.juncea(L. )Coss.)、油菜(B. campestris L.)和花椰菜(B. oleracea var. botrytis L.)等花粉形态的光学显微镜和扫描电镜的观察比较,得知它们的花粉形态特征比较一致。而与杨萍等关于芥蓝的花粉形态特征——无极,具散孔这一报道截然不同;亦与黄增泉(Huang Tseng-chieng)关于芥菜的花粉特征——不具萌发孔的报道不同。作者的研究表明,上述几个种的花粉均具3沟,沟长而明显。外壁具网状纹饰,网眼较粗。但种与种间其花粉大小有所不同。作者不同意杨萍等关于“由于芥蓝的花粉形态与芸苔属其它种的花粉明显区别,说明芥蓝与芸苔属其它种不很亲缘”的观点,而认为,从花粉形态看,芥蓝与芸苔属其它种是基本一致的,把它们置于同一自然类群是合理的。     

Investigation on Pollen Morphology of Aconitum L.

Pollen morphology of 62 species in Aconitum L. was investigated with light and scanning electron microscopies. The pollen grains in this genus are 3-colpate and exhibit spinulate surface pattern in all the species. According to the shape of pollen grains in equatorial view Aconiturn L. may be divided into three types. Type Ⅰ pollen grains are wide elliptic; Type Ⅱ are narrow-elliptic and type Ⅲ are rectangular or close to square in shape. The pollen characteristics among species are very similar. The morphological information of the pollen grains shows that species of Aconiturn L. are a natural taxon.     

Pollen Morphology of Loxostemon (Cruciferae) in China

The present paper deals with the pollen morphology of 10 species and 1 variety of Loxostemon in China. The pollen grains were all examined under light microscope. The pollen grains of Loxostemon are subspheroidal, spheroidal or prolate, 18--33×11.8-28 μ in size, 3-colpate, colpi 15-21 μ long and 1-2 μ wide. The exine is 1.5-3 μ thick with two indistinct or distinct layers. All the pollen grains are generally reticulate under light microscope. They are distinctly or obscurely and finely reticulate. L. axillus and L. repens are generally similar in gross morphology, but the pollen grains of these two species are different. The pollen grains of L. axillus are regularly polygonally reticulate, colpi are acute-ended and the exine is about 3 μ thick, whereas those of L.repens are irregularly polygonally reticulate, colpi are enlarged at both ends and the exine is about 2.8 μ thick. L. incanus and L. stenolobus appear to have similar gross morphology, but the pollen grains of the former have exines with two distinct layers and a densely and finely reticulate ornamentation and those of the latter have exines with two indistinct layers and a flexuosely reticulate ornamentation.     

国产淫羊藿属花粉形态研究

本文用光学显微镜和扫描电镜对我国淫羊藿属Epimedium 14种花粉进行比较深入的研究,试图通过花粉形态的研究为该属的植物分类和原植物鉴定提供参考依据。     

中国丁香属花粉形态的研究

本文利用扫描电子显微镜和光学显微镜,研究了丁香代表植物11种和2变种的花粉形态,并对花粉的形态特征用电子计算机进行了主分量分析,同时将计算结果作了二维与三维排序,结果表明:(1)丁香属植物花粉形态在光学显微镜下种间区别甚微,而在电镜下的区别则很明显,可做为分种的依据,尤其对形态上难以区分的种类更为适用;(2)所做花粉除欧丁香外,其余花粉均为三孔沟型,对前人的工作作了一定的修正;(3)通过主分量分析,指出了花粉孔的长宽比、沟长及网眼大小是本属花粉分类的主要成分;(4)试图通过主分量的二维和三维排序,为属下分组、分种提供新的观点和依据。     

New Materials for Chinese Brassica (Cruciferae)

The present study deals with external morphology, chromosome number, pollen morphology and seed anatomy of three species of Brassica in China. The results are summarized as follows: 1. Brassica xinjiangensis is described as a new species based on the chromosome number n=9, and 3-4-colpate and reticulate pollen grains. In the transverse section of seed, epidermal cells are triangular, semiterete or irregular, subepidermal cells consist of one series, palisade cells terete and equal in length. Leaves are petiolate or not; stems, sepals, pistils and siliquae are usually covered with retrorse-pilose hairs; rostrum stout, 12 mm long. By the above characters this species differs from others in this genus. 2. Relationship between B. nigra and B. xinjiangensis. In the former all leaves are petiolate, and the lower part of stems and leaves usually bristly; sepals, pistils and siliquae are glabrous; pedicels are erect and appressed to the axis of infructescence; rostrum is gracile, 2.5 mm long. The chromosome number is n=8. Pollen grains are 3-colpate; the exine is cerebroid-reticulate under SEM. In the transverse section of seeds, epidermal cells are undulate, subepidermal cells in 1-2 series, palisade cells terete, short and unequal in length. These characteristics are the same as reported by Koch (1833), Darlington and Wylie (1955), Goldblatt (1981), Vaughan et al. (1971), Lan (1986). 3. Taxonomical position of B. celerifolia. It was treated as B. juncea var. celerifolia by Tsen et Lee (1942). According to the chromosome number n=10, 3-4-colporate pollen grains, it deserves specific rank. This species differs from B. juncea, which has the chromo-some number n=18 and 3-4-colpate pollen grains.     

Pollen Morphology of Quercus L. in China

The present paper describes the pollen morphology of 31 species of the genus Quercus from China. The pollen grains were all examined with light microscope and scanning electron microscope, and those of some species under transmission electron microscope. Pollen grains of the genus are spheroidal or subspheroidal, 16.8-50.4μm in diameter, 3colporoidate or 3-colpate. The exine is 2-layered, 0.4-1.8μm thick, sexine thicker than nexine, granulated tuberculate or verrucate.     

Pollen Morphology of Cyclobalanopsis and Its Relation to Quercus

The present paper deals with pollen morphology of 19 species belonging to Cyclobalanopsis and of 31 species belonging to Quercus from China. All pollen grains were examined under light microscope and scanning electron microscope, and those of 4 species of Cyclobalanopsis and of 8 species of Quercus were examined under transmission electron microscope. Pollen grains of Cyclobalanopsis are spheroidal or subspheroidal, 25.2(18.9-31.5) ×23.1 (16.8-27.3) μm in size. Mostly 3-colporoidate, rarely 3-colpate or 3-colporate. The exine is 2-layered, 1.1-1.9 μm thick, sexine thicker than nexine, finely granulate under LM, granulate, spinulate, verrucate under SEM. Pollen grains of Cyclobalanopsis and of evergreen members of Quercus are very similar to each other in size, aperture and ornamentation of exine, but there are some differences in pollen grains between Cyclobalanopsis and deciduous members of Quercus. Therefore, Pollenmorphology supports the treatment of Cyclobalanopsis as a subgenus of Querc     

天仙子族(茄科)的花粉形态补充研究及其系统学意义

在扫描电镜下研究了茄科天仙子族7属及颠茄属、茄参属和枸杞属3属共10属23种植物的花粉形态学特征。结果表明:天仙子族的花粉粒形状为球形、近球形、扁球形和长球形;萌发孔类型有无萌发孔、不规则的拟孔、3沟、4沟、3～4沟、散沟和3孔沟;外壁纹饰为小刺状、瘤状、各式条纹状、条纹-穴状、条纹-网状、皱波状、细网状和网状。沟膜近光滑、具小颗粒、具小刺状突起或具瘤状突起。各属植物的花粉形态在萌发孔的有无、萌发孔的类型和外壁纹饰等方面有较大的差异,可以作为探讨属间分类和系统关系的重要依据。天仙子族植物花粉萌发孔的演化趋势为:无萌发孔→3、4沟→3孔沟。无萌发孔的山莨菪属是原始类群,三孔沟的马尿泡和天仙子等属是进化类群。还讨论了与前人研究结果不同之处和可能的原因。     

中国木犀属花粉形态研究及其系统学意义

观察了中国木犀属4组21种植物的花粉形态。花粉为圆球形或近长球形,外壁表面均具网状纹饰。大多数种类都具有三孔沟的萌发孔,极少四孔沟,或六萌发孔。内孔明显或不明显,有9种植物同时存在具三孔沟和具三沟二种类型的花粉及中间过渡类型(显脉木犀同时存在具三拟孔沟和具四拟孔沟)。很多特点表明,木犀属花粉的萌发孔在木犀科中处于由简单萌发孔向复合萌发孔过渡的阶段。根据网眼从沟间区中央到沟边是否变细,可将本属花粉分为两大类型,与分组有一定的对应关系。综合一些花粉特征,可发现本属花粉形态差异较明显,与一般形态差异有一定的相关性。花粉形态在木犀属具有一定的系统学意义。     

Study on the Pollen Morphology of the Chinese Family Oleaceae

This paper deals with the pollen grains of 11 genera, 22 species in Chinese Oleaceae. A comparative study on the pollen grains was carried out by means of scanning electron microscope and light microscope. The pollen grains of the family Oleaceae are almost spheroidal, oblate and prolate, in polar view tlie majority of the pollen grains are tri-lobulate-circular, the minority are tetra-lobulate-circular and dilobulate-circular. Pollen size: (15-65) × (12- 60)μ, 3-colporate and 3-colpate the minority of the pollen grains 4-colpate and 2- colpate colpus usually distinct and the en doaperature vague. The exine oonsists of two layers, the sexine thicker than the nexine, with big reticulum or fine reticulum, the majority of the reticulum are very distinct. On the basis of the pollen size and exine ornamentation, the pollen grains are divided into following two main types: (1) The larger pellen grains and the exine with big reticulum are found in the genera: Jasminum, Nyctanthes, Ligustrum, and Syringa. (2) The smaller pollen grains and the exine with finer reticulum are found in the genera: Osmanthus, Olea, Chionanthus, Fraxinus, Forsythia, Fontanesia and Linociera. In view of the features of pollen morphology, this family is much similar to the family Itamamelidaeeae. For example, the first pollen type resembles the genus Coryiopsis of the family Hamamelidaceae, but there are some differences between them, the former with a bigger reticulate exine and without any colpal membrane, the latter with a finer reticulate apocolpium and eolpate membrane. The second pollen type is much similar to that of the genera Hamamelis and Loropetalum of family Hamamelidaceae.     

Pollen morphology in Psychotria (Rubiaceae, Rubioideae, Psychotrieae) and its taxonomic significance. A preliminary survey

The pollen morphology in 168 species of Psychotria (Rubiaceae, Rubiodeae, Psychotrieae) has been investigated using light microscopy and, for 61 of the speices, scanning electron microscopy. Transmission electron microscopical studies have been carried out for seven of the species. Psychorria is very heterogeneoous pollen morphologically and pollen grain characteristics cannot be used for the delimination of the basis of aperture morphology, thickness of exine, size of lumina, muri, columellae and bacula, and sculpture. A key to the identificantion of the pollen types is presented and all types are issstrated. The pollen grains in Psychotria are usually 3–to 5colporte, 3-to 5-colpate or inapertuarate, rarely 2–4-or 5-porate, and have an exine that vanes widely in thickness. The sexine is reticulate, microreticulate, tectate-perforate, rugulate or intectate, and smooth or sculptured. Exine morphology presents important characters for the taxonomic subdivision of Psychotria . Previous intrageneric classifications are in part supported by pollen morphology, but contradictions between this and other sets of charactes, such as inflorescence features. are common.