关键词: 小花山桃草, 石蜡切片, 解剖结构

Abstract: Gaura parviflora is one of the invasive plants, the anatomical structure of its vegetative organs was studied by the methods of paraffin section. The results showed that: In the secondary structure of the roots of G. parviflora，there was a larger proportion of secondary xylem, about two thirds of the entire cross section, the number of vessels averaged 138.25, and the lumen diameter was 85.37 μm; The cork of the roots and stems were both developed, which was composed of 6 to 7 layers of flat cells; there were many parachyma cells containing needle crystals in the secondary phloem; The leaves of G.parviflora had the typical characteristics of xerophytes leaves: the multiple epidermis; the stomata existed in both upper and lower epidermis，whose densities were 180 mm^-2 and 266 mm^-2, respectively; the palisade tissue was two-side palisade which included 2 to 3 layers of cylindrical cells in the upper side, with a lot of chloroplasts; the main vein of leaves had well developed xylem ,with a number of radial arranged vessels. The characters mentioned above showed that G.parviflora adapted well to the dry environment.

Key words: Gaura parviflora, paraffin section, anatomical structure