关键词: 蒙古沙拐枣, 相关种, 果实形态, 差异性, 居群

Abstract: The research focus on the controversial taxonomic relationship of Calligonum mongolicum and related species (C. gobicum, C. chinense, C. pumilum, C. alashanicum, C. zaidamense, C. roborowskii ）based on 11 fruit morphology characters: fruit length, fruit weight; setae length; space between setae; space between ribs; achene length; achene width; fruit form; achene form; number of bristle rows on each rib; fruit size. The results indicate that there is significant difference among populations of C. mongolicum and related species from aspects of the 11 fruit morphology characters, and the variation degree is different; there is also a significant difference of fruit morphology characters among populations of C. mongolicum, and the difference is different, too. The results also show there are variable and overlapping states of the morphology characters among C. mongolicum and related species, and key taxonomic characters—fruit morphology can not be used as a straightforward and feasible evidence, and so these six related species (C. gobicum, C. chinense, C. pumilum, C. alashanicum, C. zaidamense, C. roborowskii) should be merged with C. mongolicum.

Key words: Calligonum mongolicum, related species, fruit morphology, difference, population