Structure of the style and pollen tube pathway in the Ziziphoid and Rhamnoid clades of Rhamnaceae.

The ultrastructure of the style and pollen tube pathway before, during and after anthesis were studied in 13 species belonging to the tribes Pomaderreae, Paliureae, Colletieae and Gouanieae (Ziziphoid clade) and Rhamneae (Rhamnoid clade) using light microscopy and transmission electron microscopy. The aim of this study is to provide new morphological characters useful for phylogenetic analysis at suprageneric level in Rhamnaceae. The patterns of pollen tube growth and the ultrastructural changes undergone by cells of the style were also described. Species of Rhamneae (Scutia buxifolia and Condalia buxifolia) have a solid style, with the transmitting tissue forming three independent strands (S. buxifolia) or a central, single horseshoe-shaped strand as seen in transversal section (C. buxifolia) which could derive from the fusion of formerly independent strands. In contrast, Pomaderreae, Gouanieae and Paliureae showed semi-solid styles, while in Colletieae, as previously reported, the style is hollow with two or three stylar canals. The style anatomy and the ultrastructure of the pollen tube pathway show that there is a tendency towards a solid style with a single strand of transmitting tissue within the family. The three-canalled hollow style could be the plesiomorphic state of the character "type of style" in the family, the semi-solid style the synapomorphic state and the solid style with three strands of transmitting tissue the apomorphic state, with the solid style with a single strand of transmitting tissue as the most derived state. Therefore, Colletieae would be the most basal tribe of the Ziziphoid clade.

[Pharmacognostical study on Berchemia floribunda].

OBJECTIVE: To study the pharmacognostical characteristics of stem and root of Berchemia floribunda for its further research and usage. METHODS: The plant was researched by macroscopic identification, microscopic identification and thin layer chromatography. RESULTS: The transverse section of B. floribunda root was eccentric. There were many fiber bundles in the secondary phloem and two different stone cells distributed in stem and root respectively. The results of TLC could identify the stem and root of B. floribunda. CONCLUSION: The microscopic characteristics of B. floribunda stem and root can be used as reference for its identification. Quercetin can be used as the characteristic component to identify the stem and root.