Supplementary Revision Of Sparganiaceae In China

Sparganium Linn, belongs to Sparganiaceae, which has 19 species, mainly distributed in temperate and cool regions of northern hemisphere, with a couple of species extending to tropical Asia, Australia and New Zealand. In China, Sparganium contains 11 species, which are distributed in South and North, especially in temperate regions. Although this genus was studied before, but now we confirmed that there are still some dubious taxa and new recoreded species in China. The two new recorded species which are S. japonicum Rothert and S. microcarpum Domin., and one dubious taxa have been reported.The experimental materials is more than 100 sheets of specimens in CCNU and more than 230 sheets of specimens in PE.The main results were as follows:1. The valuable characters for taxonomy of Sparganium was shown, such as leaf shape, inflorescence types, fruit shape, and texture, colour, shape, split case of perianth.2. Sparganium japonicum which is distributed in China was reported. Inflorescence simple, female heads strictly axillay, perianth segment not translucent, fruit fusiform, long beak, long pedicel, which are the most important morphological characteristics. S. japonicum is morphological similar to S. americanum and S. androcladum, but there are some obvious differences in branch, fruit size, fruit with glands and pits. In the quality traits, S. japonicum has fusiform and ovoid fruit, cuneate perianth segment is in the majority. There are partite perianth segment and perianth segment lived on two wheels, which suggested S. japonicum has the high evolutionary status. In quantitative traits, fruit lengh, fruit width are stable traits in 11 phenotypic traits, and the rest have significant differences. S. japonicum should belong to Sect. Natantia., and a key to the species in Sect. Natantia. was also given.3. Sparganium microcarpum which is distributed in northern China was reported. Large panicles,1-5 branches with female and male inflorescence, fruit with constriction acutely-obpyramidal below and domed above, which are most important morphological characteristics. S. microcarpum is morphological similar to S. stoloniferum, but there are some obvious differences in fruit shape, fruit size. The inflorescence lengh of S. microcarpum is half as long as that of S. stoloniferum. In Xinjiang province, S. microcarpum has inflorescence with a certain degree of variation, fruit with ridge or without ridge, stigma subulate, oval to tenuous, spathulate perianth segment. Through comparing the three group in Xinjiang region, we found that variance in populations is greater than that among populations which illustrate that it is focused on variation in population. The eight characteristics as Leaf lengh, fruit lengh and so on are stable traits. In Jilin region, it is founded that atypia fruit of S. microcarpum, and the reason remains to be proven.4. Through comparing the six group in Xinjiang region, it is founded that S. stoloniferum has inflorescence with a certain degree of variation, fruit with ridge or without ridge, globular fruit, stigma subulate, oval, linear to bifurcate, cuneate perianth segment. We also found that variance in populations is smaller than that among populations, and variation may rise to taxonomic unit. In northeast regions, it is shown a dubious taxa which is morphological similar to S. stoloniferum. We reported the morphological characteristics of it, and compared the difference between dubious species and S. stoloniferum in inflorescence, fruit, perianth segment.