娃儿藤属(萝藦科)植物花粉器形态

用光镜对我国萝藦科(Asclepiadaceae)娃儿藤属(Tylophora)17种植物的花粉器形态进行了观察。结果表明,着粉腺的形态有4种类型:长圆形、近方形、三角形和倒立三角形。花粉块的形态有3种类型:球形、长球形和超长球形。花粉块柄的长度、着粉腺和花粉块的形态和大小在种间存在较显著的差异,可作为区分种的辅助特征,对娃儿藤属植物的分类有较大意义。     

17种1亚种鹅绒藤属植物花粉器形态学研究

利用光学显微镜对萝藦科鹅绒藤属17种1亚种植物花粉器的形态特征进行观察。结果表明:(1)该属植物花粉器形状大小在各个种间差异较大:花粉块下垂,通常呈球形、长球形和超长球形,平均大小为327.2μm×183.9μm;着粉腺呈长圆形、近圆形、近方形和近三角形,平均大小为406.1μm×231.4μm。(2)翅果杯冠藤的花粉块柄最不发达,豹药藤的花粉块柄最发达。(3)白薇与朱砂藤、刺瓜与轮叶白前的花粉器特征均较相近。研究结果支持《中国植物志(第63卷)》中对催吐白前组(Sect.Vincetoxicum)的分组处理;支持将娃儿藤属(Tylophora)作为一个独特类群的观点;因国内翅果杯冠藤和美翼杯冠藤的花粉器形态存在差别,故不支持Flora of China(Vol.16)中认为翅果杯冠藤是美翼杯冠藤的错误鉴定与处理。     

牛奶菜族7属11种植物的花粉器形态

在光学显微镜和扫描电子显微镜下观察了萝藦科（Asclepiadaceae R.Br.）牛奶菜族（MarsdenieaeBenth.）7属11种植物花粉器的形态特征。该族植物花粉块直立或平展,通常呈椭圆形、长圆形、肾形或球形;花粉块膜表面平滑、波浪状、脊状或粒状;娃儿藤属（TylophoraR.Br.）的花粉块膜具独特的表面纹饰,与其它属植物差异较大;匙羹藤属和娃儿藤属的花粉块柄不发达,眼树莲属（Dischidia）和纤冠藤属（Gongronema）的花粉块柄发达。     

中国蓼属分叉蓼组和冰岛蓼属植物叶下表皮微形态研究

采用光学显微镜对中国蓼属分叉蓼组(Polygonum section Aconogonon)和冰岛蓼属(Koenigia)的21种植物的叶下表皮微形态进行了观察研究。结果表明,其叶下表皮微形态特征可分为三种类型：（1）气孔器类型为无规则型,表皮细胞多边形,垂周壁为波状;（2）气孔器类型为无规则型兼有非典型不等型,表皮细胞为多边形或不规则形,垂周壁为平直弓形或波状;（3）气孔器类型为不等细胞型,表皮细胞多边形,垂周壁为平直弓形。分叉蓼组（西伯利亚蓼除外）植物的叶表皮气孔器类型具有高度一致性,说明该组是一个自然类群。本文研究结果不支持将大铜钱叶蓼(Polygonum forrestii Diels)、铜钱叶蓼(P. nummularifolium Meissner)划归于冰岛蓼属的处理意见;支持将西伯利亚蓼(P. sibiricum Laxm.)独立成属,即西伯利亚蓼属(Knorringia Tzvel.)的观点;同时也支持仍将多穗蓼(P. polystachyum Wall.ex Meissner)和松林蓼(P. pinetorum Hemsl.)归在分叉蓼组的处理意见。     

凤仙花属（Impatiens L.）10种植物花粉形态的扫描电镜观察

利用扫描电镜观察了10种凤仙花属（Impatiens L.）植物的花粉形态。结果表明：本属花粉为单粒花粉,呈长圆形至长矩圆形,大小为20.3～46.7 μm,具角萌发孔,网状纹饰,网眼明显;根据花粉网状纹饰中网眼内是否具颗粒状突起可将其分为2类：（1）网眼内无或近无颗粒状突起,黄金凤（I. siculifer）和婺源凤仙花（I. wuyuanensis）的花粉纹饰属于这一类型;（2）网眼内有明显颗粒状突起,其余8个种的花粉纹饰均属于该类型。研究表明,花粉特征,特别是花粉粒网状纹饰中网眼内有无颗粒状突起及颗粒状突起的形态等特征,在凤仙花属内常具种水平上的可见变异,因而可作为种类划分的依据,它们在分类学上的价值应予以关注。     

山东飘拂草属叶下表皮微形态的研究

利用光学显微镜观察了飘拂草属12个类群（包括变种和变型）的叶片下表皮微形态。飘拂草属叶下表皮微形态基本特征如下：即长细胞为长筒形、短筒形,少数为近方形或多边形,边缘深波状、浅波状至近平直;无短细胞存在;刺毛仅存在于个别种中;气孔器大多为1～2列,少数2～4列;副卫细胞为圆屋顶形至三角形、圆屋顶形,少数为平行形。根据脉间刺毛的有无,可以分为无刺毛类型和有刺毛类型。根据外部形态和叶下表皮微形态上的区别,矮扁鞘飘拂草,应恢复其种级（Fimbristylis kraussiana Hochst. et Steud.）。矮两歧飘拂草作为变种处理比较好,其新等级种名为：F.dichotoma (L.) Vahl var. depauperata（C. B. Clarke）F. Z. Li et L. N. Liu comb. &; stat. nov.     

中国蓼属春蓼组植物果实形态及果皮微形态的研究

应用解剖镜和扫描电镜对中国产蓼属春蓼组（Polygonum sect. Persicaria）19种3变种植物的果实形态和果皮微形态特征进行了观察和研究。结果表明,蓼属春蓼组植物的果实形态为卵形或椭圆状卵形,具三棱、双凹或双凸,顶端渐狭,有喙或无喙;果皮微形态可分为7种类型： 洼点、浅洼点,脑纹状纹饰,拟脑纹状纹饰,网状纹饰,不规则褶皱,不规则小疣状颗粒以及密浅网状纹饰。观察结果支持将绵毛酸模叶蓼（P. lapathifolium L. var. salicifolium Sibth.）合并到酸模叶蓼（P. lapathifolium L.）,做为酸模叶蓼的异名处理;支持将长鬃蓼（P. longisetum De Br.）作为丛枝蓼（P. posumbu Buch. Ham. ex D.Don）的变种处理的意见;认为密毛酸模叶蓼（P. lapathifolium L. var. lanatum (Roxb.) Stew.）应恢复种级,圆基长鬃蓼（P. longisetum De Br. var. rotunatum A.J.Li）应升为种级;支持平武蓼（Polygonum pingwuense F. Z. Li et Y. T. Hou et S. J. Fan, sp. nov.）新种的成立。     

伞形科山芹属8种17个居群的植物花粉形态研究

该研究采用光学显微镜与扫描电子显微镜对山芹属（Ostericum Hoffm.）8种17个居群的花粉形态特征进行观察和分析,为山芹属分类鉴定与属下系统关系研究提供依据。结果显示：（1）山芹属17个居群的花粉类型包含椭圆形、近长方形、超长方形和赤道收缩形4种类型。（2）花粉赤道面观有近椭圆形、近长方形与超长方形,极面观多为三角圆形,少数为三角形。（3）花粉极轴长度为24.7~35.6 μm,赤道轴长度为10.6~17.4 μm,极轴与赤道轴的比值P/E为1.7~2.5,体积指数P×E^1/2为18.2~22.6。（4）花粉萌发孔均具三孔沟,且多为边萌发孔,角萌发孔较少,沟细长且均匀。（5）花粉赤道区外壁纹饰分为3类,即片状脑纹、长条状脑纹和短棒状脑纹,少数具有颗粒状或疣状的附着物。研究认为,山芹属植物花粉的形状与赤道区外壁纹饰类型存在较高的种内一致性,萌发孔类型、花粉中部是否凸出以及纹饰条纹长度、密集程度、附属物等特征则存在一定的种内差异性;花粉形态特征可为山芹属植物不同层次的分类鉴定与亲缘关系研究提供重要的证据。     

南五味子属（五味子科）植物叶表皮形态特征

在光学显微镜和扫描电镜下,观察了南五味子属（Kadsura Kaempf. ex. Juss.）全属11种,八角属（Illicium Linn.）2种,共108个样品的叶表皮特征。在南五味子属中,叶表皮细胞的形状、叶表皮表面的纹饰、气孔器的形状、气孔极区的形状、表皮毛的有无等性状能用于研究南五味子属种间关系,以及与五味子属（Schisandra Michaux）和八角属之间的关系。在八角目（Illiciales）中发现的一个新分类学性状（叶表皮表面具角质网纹）,支持将南五味子属分为离蕊南五味子亚属（Subg. Cosbaea）和南五味子亚属（Subg. Kadsura）。根据叶表皮形态特征,支持将南五味子亚属分为南五味子组（Sect. Kadsura）和肉蕊组（Sect. Sarcocarpon）,支持R. M. K. Saunders和林祁对某些种的归并处理。根据与五味子属和八角属叶表皮形态特征的比较,认为这3个属的叶表皮形态特征相似,但南五味子属叶表皮形态比五味子属和八角属的叶表皮形态复杂,不支持将五味子科（Schisandraceae）从八角目（Illiciales）中分出而成立五味子目（Schisandrales）的观点。     

委陵菜属锥状花柱组植物叶表皮微形态特征的研究

利用光学显微镜和扫描电子显微镜,观察了新疆委陵菜属（Potentilla L.）锥状花柱组（Sect.Conostylae(Wolf)Yü et Li）15种委陵菜植物叶表皮的微形态特征。对其叶表皮毛的类型、表皮细胞的形状及大小、气孔器的分布、气孔器类型、气孔形状、气孔大小、气孔密度、气孔指数、气孔外拱盖形态及其纹饰等指标进行分析：有几种植物叶的上表皮无气孔,而下表皮均有气孔器的分布,形状为长椭圆形、椭圆形、宽椭圆形和近圆形;气孔器的类型多为短平列四细胞型、无规则四细胞型、无规则型、围绕型和辐射型;表皮毛的类型为针状毛、带状柔毛和腺毛;表皮细胞分为不规则形和多边形;表皮毛特征、叶片表皮细胞的形状、垂周壁式样、气孔器的形状类型、气孔密度指数及蜡质纹饰等存在差异,可作为亚属间及种间分类的依据。     

Morphological aspects and phylogenetic analyses of pollination systems in the Tylophora–Vincetoxicum complex (Apocynaceae-Asclepiadoideae) in Japan

Pollinators of two Cynanchum , five Tylophora , and 16 Vincetoxicum species were observed in 26 populations in Japan. The following pollination systems were observed in 18 species: moth pollination, generalized insect pollination, wasp pollination, dipteran pollination, both dipteran and moth pollination, and autogamy. Principal component analysis based on 13 floral characters indicated that the size of the pollinator tended to increase with sizes of all characters measured. Furthermore, species that have developed interstaminal parts of the corona and concealed stigmatic chambers tend to be pollinated by long-tongued insects. The phylogenetic distribution of pollinator types showed that species belonging to Clade I are pollinated exclusively by Diptera, whereas those of Clade II are pollinated by four insect orders. The most prominent pollinator transition in the Tylophora–Vincetoxicum complex is dipteran to moth pollination. The most common morphological change of the plants from dipteran pollination to moth pollination, or vice versa, is modification of the corolla. In the Tylophora–Vincetoxicum complex, pollination mode shifts are generally accompanied by modifications of the corona and the structure of gynostegium. One hypothesis for the rapid radiation observed in Clade II is that a widely distributed species may have partitioned its distribution in the relatively near past and adapted to various environments, in which the dominant pollinators were different, and that the local races may then have diverged from each other after they were isolated.  © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 93 , 325–341.     

鹅绒藤属（萝藦科）一新变种——折叶白前

报道并描述了滇川金沙江上游干旱河谷萝藦科一新变种——折叶白前(Cynanchum forrestii Schltr.var.conduplicatumJ.Wang&F.Du)。新变种与原变种的区别在于:叶常对折,卵状披针形,先端渐尖,花冠和副花冠紫红色,每花萼的萼片之间有2个较大的及2(～4)个较小的腺体,花粉块近球形。     

The Chemotaxonomy of Cynanchum and Its Allied Genera

This paper is a continuation of “Chemotaxonomy of Cynanchum and Its Allied Genera with Notes on the Generic Characteristics of Vincetoxicum”, published in Acta Botanica Yunnanica (11: 41-50, 1989). There are other three sections of Cynanchum in “Flora Reipublicae Popularis Sinicae” (Vol. 63), which were considered as separate genera by some authors. These sections are Cynanchum Sect. Rhodostegiella, Sect. Seutera and Sect. Cyathella, also of a single corona. They were not given generic rank as chemical data of Sect. Rhodostegiella were inavailable. It is for this reason that we have studied the chemical constituents of this section. A very marvellous result was obtained. No C₂₁ steroidal compounds but flavonols were identified from the section Rhodostegiella. Some flavones were isolated from Hoya bella of Asclepiadaceae (Bass et al., 1979), but no report has been given from Cynanchum and the tribe Asclepiadeae up to now. The family Asclepiadaceae mainly contains C21 steroids, but some genera contain cardenolides or terpenoids, and only a few genera, such as Cryptolepis and Tylophora, have alkaloids. The genus Cynanchum sensu Tsiang et P. T. Li, like most members of Asclepiadaceae, has C₂₁ steroids except the section Rhodostegiella. Flavonols, therefore, may be the characteristic of the section. Considering the corona characteristics and geographical distribution, we suggest that the section Rhodostegiella be given generic rank. Because of the separation of Vincetoxicum Wolf and Rhodostegiella (Pobed.) C. Y. Wu et D. Z. Li from Cynanchum sensu Tsiang et P.T. Li, the rank of the sections Seutera and Cyathella should be reconsidered. Obviously, the problem of evolution of the sections of Cynanchum sensu Tsiang et P. T. Li is complicated. The corona, chemical constituents, habit, root-type are not congruent with one another in evolution. The authors support the establishment of the genera Seutera and Cyathella by Reichenbach (1828) and Decne (1838) respectively. Taxonomic treatments, including a new status, Rhodostegiella (Pobed.) C.Y. Wu et D. Z. Li, and 12 new combinations, are given.Key words Cynanchum Linn.; Rhodostegiella (Pobed.) C. Y. Wu et D. Z. Li; Seutera Reichb.; Cyathella Decne.; Flavonols; Chemotaxonomy; New combination     

Molecular phylogeny of Vincetoxicum (Apocynaceae-Asclepiadoideae) based on the nucleotide sequences of cpDNA and nrDNA

Molecular phylogenetic analyses of Vincetoxicum and Tylophora (Apocynaceae-Asclepiadoideae) were conducted based on the nucleotide sequences of cpDNA (two intergenic spacers of trnL (UAA)-trnF (GAA) and psbA-trnH and three introns, i.e., atpF, trnG (UCC) and trnL (UAA)), and nrDNA (ITS and ETS regions). Our phylogenetic analysis revealed two monophyletic groups; one consisted of seven taxa of Tylophora and Vincetoxicum inamoenum, Vincetoxicum magnificum and Vincetoxicum macrophyllum (Clade I) and the other consisted of 17 accessions of Vincetoxicum (Clade II). The monophyly of the genus Vincetoxicum was not supported. Although many nucleotide substitutions were observed in Clade I, the genetic differentiation within Clade II was small. Low genetic diversification but considerable morphological divergence suggests that the species in Clade II had undergone rapid diversification. Although most species in Clade I have tiny flowers, those in Clade II have larger and more nectariferous ones. Thus, we hypothesized that the rapid morphological radiation in Clade II may have been due to the gaining of floral characters such as large flowers and large amounts of nectar corresponding to diverse pollinators.     

鹅绒藤属及其近缘属的化学分类——兼论Vincetoxicum的恢复问题

本文讨论了鹅绒藤属及其近缘属的分类问题。根据这类植物所含的C_(21)甾体甙元结构类型的分类,生源合成途径假说,以及C_(21)甾休甙元的分布,结合形态学的比较分析和其它证据,认为Vincetoxicum是一个脱胎于Cynanchum,但又较之进化的自然类群,应恢复其属级地位。列举了国产白前属全部分类群的正确学名,其中包括15个新组合,1个改级新组合和1个新改级。     

The identity of the African genus Oncostemma K. Schurn. (Asclepiadaceae)

Oncostemma cuspidatum K. Schum., described from the West African island of S˜o Tomé, is recognized as being synonymous with Tylophora oblonga N.E. Br., a widespread and variable species of mainland African rainforests. The monotypic genus Oncostemma K. Schum. is reduced to synonymy with Tylophora R. Br. (Asclepiadaceae-Asclepiadeae-Astephaninae).     

Which food‐mimic floral traits and environmental factors influence fecundity in a rare orchid,Calanthe yaoshanensis?

Orchid species that are food mimics produce fewer fruits than species offering rewards, but few studies have shown the impact of environmental factors (e.g. anthropogenic activity, frost and herbivores) on their reproductive success over several seasons. In this study, we focused on the sole population of the endangered Calanthe yaoshanensis as it secretes no nectar. We investigated its floral biology, fruit set rates and prevailing environmental factors over three seasons (2008–2010). Mechanical self‐pollination did not occur in C. yaoshanensis, but hand‐selfed and crossed flowers produced equal numbers of fruit. However, seed viability and embryo size were significantly higher in cross‐pollinated fruits maximizing embryonic fitness. Large hoverflies (Syrphidae) and Bombus patagiatus (gynes) were the only pollinarium vectors, but they often failed to disperse pollinaria. We interpret the temporary retention of the anther cap over the pollinarium as an adaptation lowering self‐pollination. Insect‐mediated rates of pollinarium removal were always higher than rates of pollinia deposition on stigmas. Over 3 years, natural rates of pollinarium removal differed significantly, whereas natural rates of fruit set were not significantly different (< 22%). Climate, herbivory and anthropogenic collections also inhibited some fruit set and maturation. Both biotic and abiotic factors appear to lower the fecundity of this endangered population. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 176 , 421–433.     

Removal and insertion of pollinia in flowers of Oxypetalum (Asclepiadaceae) in southeastern Brazil

Pollinarium removal and pollinium insertion of seven Oxypetalum species (O. alpinum var. alpinum, O. appendiculatum, O. banksii subsp. banksii, O. jacobinae, O. mexiae, O. pachyglossum and O. subriparium) were recorded in Vi?osa. Minas Gerais. They presented a tendency of one or two pollinarium removals and one pollinium insertion (single insertion), except O. appendiculatum. In this species, mainly, two pollinia of the same pollinarium were inserted per stigmatic chamber (double insertion), resulting exceptionally in 6-10 inserted pollinia in a flower, an unusual occurrence among the Asclepiadaceae. No association between removal and insertion was found, e.g., O. subriparium and O. banksii subsp. banksii had the highest pollinarium removal (1.78 and 1.45, respectively) and one of the lowest pollinium insertions (0.02 in both species), per flower. Oxypetalum mexiae showed the lowest pollinarium removal and pollinium insertion per flower (0.09 and 0.01, respectively) among the studied species and other Asclepiadaceae. Oxypetalum subriparium, O. banksii subsp. banksii and O. mexiae might be having reproductive limitations. Pollinarium removal and pollinium insertion per flower of the studied species varied from site to site, similarly to what was recorded for other Asclepiadaceae.     

Floral features,pollination biology and breeding system of Chloraea membranacea Lindl. (Orchidaceae: Chloraeinae)

Background and Aims

The pollination biology of very few Chloraeinae orchids has been studied to date, and most of these studies have focused on breeding systems and fruiting success. Chloraea membranacea Lindl. is one of the few non-Andean species in this group, and the aim of the present contribution is to elucidate the pollination biology, functional floral morphology and breeding system in native populations of this species from Argentina (Buenos Aires) and Brazil (Rio Grande do Sul State).

Methods

Floral features were examined using light microscopy, and scanning and transmission electron microscopy. The breeding system was studied by means of controlled pollinations applied to plants, either bagged in the field or cultivated in a glasshouse. Pollination observations were made on natural populations, and pollinator behaviour was recorded by means of photography and video.

Key Results

Both Argentinean and Brazilian plants were very consistent regarding all studied features. Flowers are nectarless but scented and anatomical analysis indicates that the dark, clavate projections on the adaxial labellar surface are osmophores (scent-producing glands). The plants are self-compatible but pollinator-dependent. The fruit-set obtained through cross-pollination and manual self-pollination was almost identical. The main pollinators are male and female Halictidae bees that withdraw the pollinarium when leaving the flower. Remarkably, the bees tend to visit more than one flower per inflorescence, thus promoting self-pollination (geitonogamy). Fruiting success in Brazilian plants reached 60·78 % in 2010 and 46 % in 2011. Some pollinarium-laden female bees were observed transferring pollen from the carried pollinarium to their hind legs. The use of pollen by pollinators is a rare record for Orchidaceae in general.

Conclusions

Chloraea membrancea is pollinated by deceit. Together, self-compatibility, pollinarium texture, pollinator abundance and behaviour may account for the observed high fruiting success. It is suggested that a reappraisal and re-analysis of important flower features in Chloraeinae orchids is necessary.