Three new species ofGalium (Rubiaceae) from Pakistan

Three new species ofGalium from the NW. Himalaya in Pakistan are described and illustrated.Dedicated to Prof.K. H. Rechinger on the occasion of his 80th birthday.     

Revision and affinities ofGalium (Rubiaceae) in Madagascar

The only representatives ofRubiaceae-Rubieae in Madagascar are five species ofGalium. G. thunbergianum andG. chloroionanthum are essentially afromontane species, ± widely distributed in both the African mainland and Madagascar. The new speciesG. andringitrense andG. ankaratrense are endemic to Madagascar but show close affinities to two afromontane—afroalpine groups from the African mainland, theG. simense—G. ruwenzoriense andG. glaciale complex respectively.G. polyacanthum (new combination) exhibits certain primitive morphological traits and appears to be an old Madagascan endemic without close allies. New chromosome counts for populations from the African mainland demonstrate thatG. chloroionanthum andG. simense are 4x (x=11). Distribution patterns and origins of theGalium species in Madagascar and their relationships with African taxa are discussed.     

Leaf flavonoids and other phenolic glycosides and the taxonomy and phylogeny of fuchsia sect. skinnera (onagraceae)

In a leaf flavonoid investigation of all species and one hybrid of Fuchsia sect. Skinnera flavonol glycosides were found in all except F. procumbens and F. perscandens. Flavone glycosides and their sulphates previously characterized in F. excorticata, F. procumbens and their hybrid were found additionally in F. perscandens and F. colensoi but were absent from F. cyrtandroides. However, the rare Fuchsia constituents diosmetin 7-glucuronide and eriodictyol 7-glucoside were identified only in F. excorticata, F. excorticata x F. procumbens and F. colensoi, supporting the suggestion that the latter species is of hybrid origin with F. excorticata as one of the parents. The chemical evidence also indicates that sect. Skinnera is monophyletic with the Tahitian F. cyrtandroides, a sister species to a clade incorporating all the New Zealand species and thus not necessarily derived from a New Zealand ancestor.     

Leaf Nodule Development in Psychotria kirkii Hiern. (Rubiaceae)

The initiation, development and structure of the leaf nodulesof the Rubiaceous shrub Psychotria kirkii Hiern. has been studiedin detail at the ultrastructural level. Bacteria, maintainedin the shoot tip in the secretions from dendroid colleters,invade the substomatal chamber of stomatal pores which formprecociously on the abaxial leaf surface. Proliferation of theepidermis around the pore pushes the bacterial cavity deep intothe lamina, thus forming a small internal nodule. Endophyte-mediatedschizogeny of the cells surroundng the nodule causes it to expandwhile at the same time giving rise to an interconnected reticulumof invasive host cells which are involved in metabolite exchangebetween microoganisms and host plant. Bacterial morphology changesafter entry of the microsymbiont into the host plant and, bythe time the nodule is mature, the bacteria exhibit distinctpleomorphism. Senescent nodules are shown to accumulate lipidand starch. The developmental process is discussed in the lightof existing information on this symbiosis. Psychotria kirkii, leaf nodule development, symbiosis, ultrastructure     

Enzyme analysis of genetic variation and relationships in diploid and polyploid taxa ofGalium (Rubiaceae)

Allozyme variation at 11 loci (with 37 alleles) was studied electrophoretically in seven outbreeding, closely related diploid and tetraploid taxa, seven from sect.Leptogalium and two from sect.Leiogalium. Whereas the sections are clearly distinct by several different alleles, aggregates, species and subspecies differ only in the frequency or presence/absence of common alleles. The resulting dendrogram suggests phylogenetic relationships and is supported by other multidisciplinary evidence. Tetraploids have originated independently in several groups, and there is evidence for tetrasomic inheritance and thus for autopolyploidy in spite of normal meiotic bivalent pairing and partly suspected hybrid origin. Tetraploids differ from related diploids only little in number of alleles and expected heterozygosity within populations, but clearly exhibit higher numbers of genotypes. This often corresponds to their greater morphological variability, increased adaptive flexibility, and better colonizing capacity compared to related diploids.     

New endemic taxa ofAsperula sect.Cynanchicae (Rubiaceae) from the East Aegean Islands

A new species and a new subspecies ofAsperula are described and discussed in regard to their affinities.     

Leaf architecture of the genus Didymaea Hook. f. (Rubiaceae)

We examined 532 specimens representing eight species of Didymaea (Rubiaceae) to describe their leaf architecture. Characters observed in the herbarium specimens and cleared leaves were leaf base, apex, and margin; trichome type and distribution; vein orders from primary to higher order veins, veinlets, and ultimate marginal vein. Six morphometric variables were analyzed using variance and principal component analysis to identify which characters are useful to distinguish species. Most of the species present brochidodromous venation pattern, except D. hispidula, which has eucamptodromous venation pattern; Didymaea floribunda is unique in having cylindrical and bicellular trichomes. Principal component analysis revealed that 78% of the total variation is mainly related to leaf maximum width. Variance analysis showed significant differences between D. microflosculosa and the other species. Architectural features were useful for differentiating all the species, and an identification key for the species of Didymaea based only on leaf characters is presented.     

野丁香属植物叶表皮形态特征研究

在光学显微镜和电子扫描显微镜下观察了茜草科(Rubiaceae)野丁香属(Leptodermis Wall.) 35种8变种植物的叶表皮微形态特征.结果表明,野丁香属植物叶表皮细胞为多边形或不规则形状,垂周壁平直、弓状或波状.气孔器全部位于下表皮,有辐射型、平列型两种,其中平列型较为普遍.表皮毛在上下表皮都有分布,有单...     

Leaf anatomy of Camellia sect. Oleifera and sect. Paracamellia (Theaceae) with reference to their taxonomic significance

Leaf anatomy of 21 species representing sect. Oleifera H. T. Chang and sect. Paracamellia Sealy in the genus Camellia was investigated using light microscopy. All the shapes of leaf epidermal cells were polygo-nal, and the patterns of anticlinal walls were sinuolate or sinuous, which were important to the classification of these two sections. The stomata were cyclocytic type and only present on the abaxial epidermis in both sampled sections. Seventeen leaf anatomical and cytologic characters were selected and used for the cluster analysis and principle components analyses performed by PAST program. Congruent results were obtained, with sect. Oleifera and sect. Paracamellia consistently grouping in two different clades, and some related species nesting together. This study provided leaf anatomical evidence for the merge of C. lanceoleosa H. T. Chang & J. S. Chiu and C. fluviatilis Hand.-Mazz.; of C. brevistyla Coh. St., C. obtusifolia H. T. Chang, and C. puniceiflora H. T. Chang; and of C. grijsii Hance and C. shensiensis H. T. Chang. In addition, it was also proved that C. tenii Sealy should be segregated from sect. Paracamellia and placed in the sect. Corallina Sealy. For further interest, we suggested that C. phaeoclada H. T. Chang be recognized as a subspecies of C. microphylla (Merr.) Chien. Overall, the results presented provided new insights into the relationships within a number of Camellia plants and sug-gested directions for future studies.     

山茶属油茶组和短柱茶组叶解剖特征及其分类学意义

在光学显微镜下观察了山茶属Camellia油茶组sect.Oleifera和短柱茶组sect.Paracamellia 21种（张宏达系统）植物叶解剖特征。结果表明：叶表皮细胞形状均为不规则形;垂周壁式样浅波状或波状,对两组分类具有重要作用。气孔器只存在于叶的下表皮,均为环列型。基于17个叶解剖学及细胞学性状,应用PAST软件对两组进行聚类分析和主成分分析,结果表明：能将两组植物进行明显区分,并且各组中亲缘关系较近的种聚在一起。本研究结果支持将大姚短柱茶C.teniiSealy归入离蕊茶组sect.Corallina;支持狭叶油茶C.lanceoleosa H.T.Chang ＆ J.S.Chiu与窄叶短柱茶C.fluviatilis Hand.-Mazz.,短柱茶C.brevistyla Coh.St.与钝叶短柱茶C.obtusifolia H.T.Chang和粉红短柱茶C.puniceiflora H.T.Chang,长瓣短柱茶C.grijsii Hance与陕西短柱茶C.shensiensis H.T.Chang的合并;建议将褐枝短柱茶C.phaeoclada H.T.Chang作为细叶短柱茶C.microphylla（Merr.）Chien的亚种。研究证明山茶属植物的叶解剖性状在属内分类中具有重要的分类学意义。     

中国茜草属sect.Oligoneura的形态计量学研究

茜草属为茜草科模式属,全球约80种,中国有近一半的物种,是茜草属的重要分布中心,大部分隶属于sect.Oligoneura。但是,该组内各种间的形态特征错综复杂,依靠单个性状不易划定种间界限。该研究在全面衡量sect.Oligoneura组内各种间形态特征的基础上,选取该组20种共171份标本,对其3个数量性状和28个定性性状进行聚类分析和主成分分析。结果表明:在主成分分析中,前3个主成分累积贡献率有46.88%,性状的累积贡献率增长并不明显,但该结果仍与聚类分析结果一致。对前3个主成分贡献较大的特征包括叶形(叶长宽比)、叶柄长度、叶脉、每轮叶片数和生活型等,这些形态性状也是该属传统分类学中重要的物种鉴定特征。该研究结果与分子系统发育结果基本一致,支持该组内ser.Chinenses、R.mandersii group、R.angustissima group和R.siamensis group类群的划分,但并不支持ser.Cordifoliae单独成系。sect.Oligoneura内除少数物种外,大部分物种界限均比较清晰。形态计量学研究为sect.Oligoneura甚至茜草属的物种鉴定与划分提供了重要的参考意义。     

Development and Structure of Bacterial Leaf Nodules in Psychotria bacteriophila Val. (Rubiaceae)

The development and mature structure of bacterial leaf nodules in Psychotria bacteriophila were studied by using light and electron microscopy. Bacteria in mucilage surrounding the shoot apex pass through certain stomates in leaf primordia into the substomatal chamber. These chambers enlarge and become nodules as the yound leaves grow out of the apical region. Surrounding mesophyll cells grow into each nodule and form a cellular reticulum whose interstices are occupied by bacteria. Each intrusive mesophyll cell wall is unusually thick and continually supplemented by vesicles originating from dictyosomes. The gram-negative bacteria are often surrounded by capsules. Nodule bacteria contain several crystal-like dense bodies. A population of normal, dividing, and degenerating bacteria is found in each nodule. Extensive membranes occur between the bacteria. A hypothesis is proposed to explain certain aspects of this obligate symbiotic relationship.     

Leaf flavonoids from Croton urucurana and C. floribundus (Euphorbiaceae)

Flavonoids were isolated by PVPP column chromatography of leaf extracts of Croton floribundus Spreng and C. urucurana Baill. and identified by NMR and co-chromatography with standards. The two species revealed highly distinct flavonoid profiles. C. urucurana, belonging to the phylogenetically basal section Cyclostigma, yielded the flavone C-glycosides vitexin and orientin, quercetin and the O-glycosides quercetin 7-O-rhamnoside, rhamnitrin and rutin, in addition to tiliroside. Instead, C. floribundus, from the more derived section Lasiogyne, yielded no C-glycosides, but a high diversity of classes of flavonols, including kaempferol, three flavonol O-methyl ethers, isoquercitrin, three tri-O-galactosides, in addition to tiliroside and an isorhamnetin-coumaroyl-O-glycoside. The present work is the first report for Croton of two rhamnosides (isolated from C. urucurana). It is also the first report for Euphorbiaceae of two tri-O-glycosides obtained from C. floribundus. The distribution of flavonoids in the two species as determined by HPLC-DAD of extracts of small leaf samples of herbarium specimens is highly similar with the profiles resulting from isolation of compounds from bulky leaf samples. Differences among specimens of the same species were restricted to relative proportions of individual constituents. The results indicate that flavonoid profiles are effective to characterize and distinguish the two species. The present results, combined with literature data, supports the condition of tiliroside as a marker of Croton and the hypothesis of an evolutionary trend in the genus toward the loss of C-glycosides and a progressive complexity of flavonoid profiles.     

Evidence for Cytokinin in Bacterial Leaf Nodules of Psychotria punctata (Rubiaceae)

Cytokinin activity based on two bioassays was at least 100-fold higher in Psychotria punctata leaf discs with bacterial nodules than in discs without them. Nodulated discs from young leaves yielded 0.4 to 6 μg of cytokinin (zeatin equivalents) per g fresh weight of leaf tissue, whereas non-nodulated discs from the same leaves yielded 0 to 0.003 μg per g fresh weight. These estimates probably include free-base cytokinins and, if present, any nucleoside cytokinins precipitable by acidic silver nitrate. Cytokinin concentrations in Psychotria leaf nodules appear to be higher than normally found in green leaves of other plants. In l-butanol-acetic acid-water (12:3:5, v/v), the one peak of activity chromatographed with an R_F similar to zeatin's, but both number and identity of the active substance(s) remain unknown. These findings suggest that a cytokinin is produced by bacteria in leaf nodules of P. punctata and that it is involved in the symbiosis.     

山茶属金花茶组金花茶系植物叶表皮形态学研究

在光学显微镜下观察山茶属金花茶组金花茶系25个分类群的叶表皮形态。结果表明:25个分类群的叶上表皮形态结构相似,气孔仅分布于下表皮。下表皮的细胞垂周壁式样和气孔形状在一些种间存在着明显的差异。分布于不同地貌类型的金花茶种类的气孔密度存在显著差异,分布在石灰岩山地的种类的气孔密度在整体上明显高于分布在非石灰岩山地的种类。     

亚洲粗叶木属及相关属植物叶表皮微形态特征

利用光学显微镜和电子扫描显微镜研究了亚洲茜草科粗叶木属植物26种（包括1个亚种和2个变种）和相关4属即巴戟天属、九节属、染木属和尖叶木属6种植物的叶表皮微形态特征。粗叶木属植物上表皮细胞形状一般呈不规则波状、近椭圆形或者不规则多边形,下表皮细胞一般呈不规则皱波状或者多裂深波状,细胞壁曲折无章,细胞间界限不明显,上、下表皮细胞壁均有加厚现象。叶表皮角质层明显,在电镜下有以下几种类型：颗粒状,网状,鳞片状,乳突状。气孔器几乎全部生在下表皮,有些种气孔下陷,气孔器一般是一对保卫细胞和一对副卫细胞平列。一些粗叶木属植物种叶上着生表皮毛。表皮毛分为单细胞毛和单列多细胞毛两种结构类型以及扭曲毛,线形毛和直壁毛3种形态类型。相关属的叶表皮微形态特征与粗叶木属植物较为相似。粗叶木属植物叶表皮微形态特征具有一定的分类学价值,其性状虽有遗传稳定性,但随生态环境不同而有一定变异。粗叶木属植物叶气孔长轴径/径轴变化幅度比较大以及叶表皮上的毛被多样化均能反映其对生态环境的适应变化。     

Cladistics and Biogeography of Artemisia sect. Viscidipubes and sect. Albiraotea (Compositae)

Twenty-six species and eight varieties of Sect．Viscidipubes & Sect．Albibractea are endemic to Asia．Most species of Sect．Viscidipubes are distributed from low to high altitudes and cold areas in the Hengduan-Himalayan Mountains,with only a few species extending to E or S Asia．Sect．Albibractea is distributed mainly in the subtropics and tropics,lower altitudes and moist areas in S & SE Asia,with a few species extending to the Qinling range of China．Both sections are more advanced than the other sections．They were studied by cladistic analysis and outgroup comparison．Data matrix of 55 characters from stems,leaves,inflorescences,female flowers,bisexual flowers,achenes,pollen grains and chemical constitution was employed in separate and combined studies．Eighteen most parsimonious cladograms were generated with 358 steps,consistency index of 0．72 and retention index of 0．87． 1．Within Artemisia,Sect．Viscidipubes and Sect．Albibractea are sister groups to all the other groups． 2．We support the idea to separate Sect．Viscidipubes (incl．Ser．Viscidipubes,Ser．Erlangshanenses and Ser. Pleiocephalea) and Sect．Albibractea (incl．Ser．Albibractea,Ser．Flaccidae and Ser. Anomalae)．The authors suggest that Ser．Anomalae include A．deversa and Ser．Erlangshanenses include A．zayuensis and A．yadongensis as well as Ser．Viscidipubes include A．gyitangensis and A．boreali-siamensis．As the result of the cladistic analysis,the authors tend to propose a new series, Ser．Tanguticae,incl．A．tangutica in the section． 3．We consider that SW China,especially W Sichuan,is the speciation center and the tration of the present distribution center．4．A．boreali-siamensis,only in N Thailand,is not related to the widely distributed species in Ser．Pleiocephalae,such as A．atrovirens,A．chingii and A．myriantha,but rather closely related to species,such as A．vexans,A．occidentali-sichuanensis,which are endemic to W.Sichuan and E．Xizang．     

Synopsis ofVerbesina sect.Ochractinia (Asteraceae)

A taxonomic revision ofVerbesina sect.Ochractinia is presented. 40 species plus 7 additional infraspecific taxa are recognized. A table of the distribution of the species, key to the species and synonymy are included. Relationships to other sections ofVerbesina and species relationships within sect.Ochractinia are discussed.