玉叶金花属及其近缘属植物的叶脉序特征研究

he classification of Mussaenda L. has been controversial due to the complexinterspecific variation and hybridization within the genus, by exploring the variation patterns andtaxonomical significance of the leaf venation characteristics between Mussaenda L. and itsrelative genera (Schizomussaenda Li and Psudomussaenda Wernham.), it could be provide datafor the identification and utilization when they were regarded as the medical and garden plantresources. The leaf venation characteristics of 22 species of this group were observed by using thecleaning method. The cluster analysis was carried out based on the characteristics of leaf venation,and a classification retrieval table of the species was compiled. The results were as follows: (1)The characteristics of the leaf venation of Mussaenda L. and its relative genera had consistency,which were mainly reflected on that the primary veins were all pinnate, the frequency of intersecondaryveins was less than one per areolation, the angle between the major secondary veins andthe midvein was acute, the tertiary veins were mostly penetrating, and the arrangement of the areolation were all irregular. (2) The characteristics of the leaf venation with taxonomic valueamong genera or species within genera included the type of major secondary vein venation, theangle between the major secondary vein and the midvein, the spacing between the majorsecondary vein and the midvein, the connection between the major secondary vein and themidvein, the existence of inter-secondary veins and intramarginal secondary veins, the penetrationof intercostal tertiary veins, the type of quaternary veins, the branching of freely ending veinlets,and the development of areolation. (3) According to the cluster analysis, the 22 species wereclustered into 12 branches, and Schizomussaenda and Psudomussaenda were not clustered intoone branch respectively, showing a relatively close genetic relationship. In conclusion, the leafvenation characteristics of Mussaenda and its related taxa can provide new information for theclassification of the plants.