OBSERVATION ON FLORAL MORPHOLOGY AND HETERANTHERY OF ELEUTHEROCOCCUS SENTICOSUS (ARALIACEAE)
刺五加花的形态学及雄蕊异长现象的观察

Three morphs of Eleutherococcus senticosus with different filament lengths were found in the Maoershan Forest Ecological Station, Shangzhi County, Heilongjiang Province (127?0'~127?4'E,45?5'~45?5'N).The inflorescence and floral morphology,flowering pattern, heteranthery with reciprocal style lengths were observed. The result reveals that long filaments are 3.96~4.44 mm long,short filaments 0.45~0.93 mm,and medium-long filaments 2.16~3.08 mm. Other aspects of the heterandrous syndrome are exhibited in anther size,anther shape and color, pollen size, pollen number per flower, stigma width, fertility of stamens and gynoecium etc. The long filaments are accompanied with plump and white anther, large numbers of pollen grains, shorter style and sterile gynoecium; the short filaments with small,tawny or pale yellow anther,no pollen,longer style and fertile gynoecium;and the medium-long filaments with middle anthers, larger but half-sterile pollen grains and fertile gynoecium. On the basis of morphological data,it is confirmed that Eleutherococcus senticosus is a species with three sexual morphs, the morph with long filaments is male, and that with short filaments is female, whereas the morph with medium-long filaments is hermaphroditic. Furthermore, the relationships among these three morphs are discussed, and it is pointed out that the treatment of plants with short stamens as a variety, var. brevistaminea , is obviously a mistake.