Akira Takahashi

The survey of wild and partly cultivated Ephedra fields was carried out to elucidate the situation of the resources of Chinese crude drug Mahuang in China, in 2001 and 2002. The result showed that the abundance of Ephedra plants has been markedly reduced in the last 10 to 15 years. The cause of the reduction is considered to be as the combined effect of reclamation of wild Ephedra fields, over harvesting, the limited adaptability of the plant to climatic change, over grazing, etc. For the protection of Mahuang resources, we conclude that prohibiting land reclamation for agriculture is the most effective action.

Swollen lignotuberous roots of Agapetes serpens, A. incurvata var. hookeri, and Vaccinium nummularia of the Ericaceae are described anatomically. They are epiphytic shrubs that grow on tree trunks in subtropical or warm-temperate mossy forests of Nepal. In the swollen roots, a great amount of the secondary xylem is occupied by large multiseriate rays, and other xylem elements are restricted to narrow strips. This basic structure is consistently observed in the three species, but several features are different between the two genera. Only in the swollen roots of Agapetes, groups of radial strands of strongly procumbent cells are interspersed between the square and upright cells of the large multiseriate rays. Xylem elements restricted in the narrow strips are vessel elements, fiber tracheids, axial parenchyma cells, and uniseriate ray cells. All the elements are small in diameter. The large multiseriate rays are composed of thin-walled and less lignified large parenchyma cells. They are produced both from widening of small-sized ray cells(initials)and from transformation of fusiform initials into ray cell initials. It is considered that the large parenchyma cells of rays function as water storage and that groups of radial strands of strongly procumbent cells function as radial transport tissue.