Studies On The Anatomy And Seed Micromorphology Of 15 Species In Impatiens L.

Anatomy arid seed micromorphology of 15 species of Impatiens L. have been studied for the first time. Results are as follows:1. The main morphological characters of 15 species of Impatiens are the number of the vein,the inflorescences sessile or pedunculate, the number and the colour of the flower, the characteristic of the flower' structure and the shape of the capsule, and so on. But these morphological characteristics are easy to be impacted by environment and have more variability. So, sometimes it is difficult to use these characteristics to identify Impatiens that have numerous species.2. There are some differences in the structure of the gynoecium of the 15 species in Impatiens. The differences include the number of the carpel, the number of the locule, the shape of the ovary' s wall, the amount of the ovule, and so on. Two types can be divided according to the number of the carpel and the locule, namely, the 4 carpels and 4 locules, and the 5 carpels and 5 locules. Impatiens pritzelii, I.polyneura and I. stenosepala belong to the former type, and the other species belong to the latter type. Basing on the shape of the ovary' s wall, three types can be divided, that are the flange type, the moon type and the plane type.3. Stem morphology and characteristic of calcium oxalate crystals in 15 species in Impatiens are first studied. The results showed that there are little anatomical differences between the 15 species, but the diversity of the characteristic of calcium oxalate crystals is big. All of the 15 species of Impatiens contain raphides. According to morphological characters of the raphides, three types of the raphides are divided as following: focal raphides, clustered raphides and scattered raphides. Besides, the shape, length, distribution and the abundance degree of the raphides are different among the 15 species in Impatiens. The characteristic of calcium oxalate crystals seems to be of important significance in Impatiens taxon.4. Micromorphological features of seed surface of 15 species in Impatiens are examined under the scanning electron microscope (SEM). According to the characters of the epidermal ornamentation of seed coat and the granules on the cell surface, the micromorphological features of seed surfaces in Impatiens can be divided into 4 types, namely, laevigate, granulate, reticulate and protrusive. The latter two types can be further divided into subdivisions according to the shape of the epidermal ornamentation of the seed coat. The areolate subtype and the reticulate-colliculate subtype are observed for the fist time. The results show that there are predominant differences among the 15 species, and therefore can be used as reliable diagnostic characters to identify species.The anatomy, especially including the study on the calcium oxalate crystals in stems and the anatomical characteristic of the gynoecium' s, and the seed micromorphology of 15 species in Impatiens, have enriched systematic data of Impatiens, which will be much significant both in taxonomic research and in discussion of systematic relationships.5. The taxonomic status of Impatiens siculifer Hook, f. var. porphyrea Hook. f. is discussed. The researchs show that there are much difference between the Impatiens siculifer Hook. f. var. porphyrea Hook. f. and the Impatiens siculifer Hook. f., such as the diversities of the anatomical characteristic of the gynoecium' s and characteristic of the calcium oxalate crystals in stems. According to these results along with the difference in the morphology and the habitat, we think impatiens siculiferHook, f. var. porphyrea Hook. f. maybe rank an independent species.