Biodiversity Hotspots from a Multigroup Perspective: Mosses and Senecios in the Transmexican Volcanic Belt

Geographical information for 703 mosses and Senecios (species of the tribe Senecioneae, Asteraceae) has been analyzed to identify patterns of species richness in the Transmexican Volcanic Belt (TMVB) of Mexico. Because the TMVB holds a high proportion of these taxa (596 mosses out of 980, and 107 Senecios out of 228) in the country, it is considered a high diversity area. However, the biodiversity is not uniform, as shown by the number of species in each of seventy nine 0.5° latitude and 0.5° longitude cells covering the surface area of the mountain range. Nineteen cells were identified as hotspots and further analysis showed that 11 of such hotspots were common to both groups. The application of a heuristic iterative method and a complementarity criterion indicated that the selection of 18 cells would conserve the total diversity of mosses and Senecios found in such hotspots.     

Wood anatomy of the endemic woody Asteraceae of St Helena I: phyletic and ecological aspects

Quantitative and qualitative data are given for samples of mature wood of all eight species of woody Asteraceae, representing three tribes, of St Helena I. The quantitative features of all except one species are clearly mesomorphic, corresponding to their mesic central ridge habitats. Commidendrum rugosum has more xeromorphic wood features and occurs in dry lowland sites. Commidendrum species are alike in their small vessel pits and abundant axial parenchyma. Melanodendrum agrees with Commidendrum in having fibre dimorphism and homogeneous type II rays. The short fibres in both genera are storied and transitional to axial parenchyma. Elongate crystals occur in ray cells of only two species of Commidendrum , suggesting that they are closely related. Wood of Commidendrum and Melanodendrum is similar to that of the shrubby genus Felicia , thought closely related to Commidendrum on molecular bases. Commidendrum and Melanodendrum have probably increased in woodiness on St Helena, but are derived from shrubby ancestors like today's species of Felicia. Petrobium wood is paedomorphic and indistinguishable from that of Bidens , from which Petrobium is likely derived. The two senecionid species (Senecio leucadendron = Pladaroxylon leucadendron; and Senecio redivivus = Lachanodes arborea , formerly Lachanodes prenanthiflord) also show paedomorphic wood. Wood of the various St Helena Asteraceae is consonant with relationship to African or South American ancestors that reached St Helena via long distance dispersal. Derivation from genera of Pacific islands or Austromalesian regions is considered less likely. However, DNA evidence is needed to clarify origins, times of colonization on St Helena and divergence from closest relatives, and the nature of evolutionary patterns.     

稻城千里光(菊科-千里光族)的名实订正

通过标本(包括模式标本)检查,发现稻城千里光(Senecio daochengensis Y. L. Chen)与黑褐千里光(S. atrofuscus Grierson)属于同一种植物,故将前者处理为后者的异名。提供了黑褐千里光的地理分布图及其与近缘种的检索表。     

中国橐吾属(菊科-千里光族)的分类学研究(三)：芥形橐吾、岷县橐吾和半裂橐吾的名实订正

将芥形橐吾（Ligularia brassicoides Hand.-Mazz.）、岷县橐吾（L. ianthochaeta C. C. Chang）和半裂橐吾（L. paradoxa Hand.-Mazz. var. palmatifida S. W. Liu     

心叶合耳菊(菊科-千里光族)的名实订正

发现心叶合耳菊（Synotis cordifolia Y. L. Chen）（菊科-千里光族）的模式标本与早已处理为红缨合耳菊 [S. erythropappa (Bur.     

新疆千里光族花粉形态研究

在光学显微镜和扫描电镜下,对分布于新疆的菊科千里光族４属２６种植物的花粉进行了观察。根据萌发沟长短和外壁纹饰待征将各属分成二种类型：（１）具长萌发沟：有橐吾属、千里光属和多榔菊属。（２）具短萌发沟：仅有款冬属。由此可看出,款冬是较独立的一类,与其余各属在亲缘关系上相距较远。花粉形态特征为多榔菊属分类地位的探讨提供了资料。同时也为橐吾属两新种的成立提供了孢粉学证据。     

Occurrence of pyrrolizidine alkaloids in three Ethiopian Solanecio species

Three Ethiopian Solanecio species, namely Solanecio angulatus (Vahl) C. Jeffrey, Solanecio mannii (Hook. f.) C. Jeffrey, and Solanecio tuberosus (Sch. Bip. ex A. Rich.) C. Jeffrey var. tuberosus were analysed by capillary gas chromatography–mass spectrometry (GLS–MS) for their pyrrolizidine alkaloid content. All the extracts investigated contain pyrrolizidine alkaloids. Whilst only traces of alkaloids could be detected in the leaf extract of S. angulatus, the content of alkaloids in the other samples ranged between 0.13% dry weight (for the flowers of S. angulatus) and 0.58% (for the tubers of S. tuberosus). Altogether 17 alkaloids were detected out of which 14 were unambiguously identified by comparing their retention indices, molecular masses and mass fragmentation patterns with defined reference data from PAs database or in some cases with reference compounds. The hepatotoxic macrocyclic diesters senecionine and retrosine figured as major alkaloids in the flowers of S. angulatus, whereas the platynecine type alkaloid, 7-O-senecioylplatynecine occurred in higher amount than the other alkaloids detected in the leaves of S. mannii. The tuberous annual herb, S. tuberosus contains eruciflorine as a major alkaloid in the leaves, flowers and tubers. Senecionine figures as one of the major components of the tubers of S. tuberosus. To the best of our knowledge this is the first published report on the occurrence of pyrrolizidine alkaloids in the genus Solanecio. In addition to the chemotaxonomic significance of the detected alkaloids, a brief remark is made on the findings in the light of the use of these plants as medicinal herbs and/or as nectar or pollen source for the production of honey.