Abstract: Macro- and micro-morphological characteristics of fruits in eight species of the genus Koenigia L. (Polygonaceae) from China were observed under stereoscope and scanning electron microscope (SEM). Based on the results, the fruits of the studied species are divided into type Ⅰ, Ⅱ and Ⅲ. In type Ⅰ: Achene is ovoid to lati-ovoid, intumescently in the middle to up middle, as a double burning glass. Its surface is smooth or rough, favulariately, or undulately. Four species, K.islandica, K.nummularifolium, K.forrestii and K.fertilis are in this type. In type Ⅱ: Achene is ovoid. Its intumescent in the middle, also have three ridged arrises but not notable. One species, K.delicatula is in this type. In type Ⅲ: Achene is ovoid. Maximum width occurred in middle but non-intumescent. Its have three ridged arrises. Their surface are smooth, rugosely, concave-convexly, or verrucately. This type contained three species, K.nepalensis, K.cyanandra and K.pilosa. According to the morphological characteristics of fruits, K.cyanandra and K.pilosa exist independently; K.islandica might be closely related to K.fertilis.

Key words: Koenigia, fruit, macromorphology, micromorphology