中国特有的永瓣藤属植物区系地理性质与特征

On the feature and characteristics of floristic geography of genus Monimopetalum Rehd. endemic in China

永瓣藤是卫矛科的单型属（ＭｏｎｉｍｏｐｅｔａｌｕｍＣｈｉｎｅｓｅＲｅｈｄ），为中国特有的珍稀濒危植物，分布于北纬２８°３０′～３０°１０′和东经１１４°３０′～１１８°１０′的长江中下游南岸地区。文中研究了永瓣藤的自然地理环境与群落特征，分布区的历史和分布格局的现状，探讨了它起源的时间、地区及区系地理性质。研究结果表明：（１）永瓣藤适应于温暖湿润和偏酸性（ｐＨ５．５～６．５）土壤的地理环境；它是群落的伴生成分，其分布受到杉木、马尾松、毛竹、赤杨叶等优势成分的影响。（２）其分布区的地史演变大概为：连续分布（新第三纪）→间断分布（第四纪及以后）→星散分布（现状）。通山县的残存为湖北省植物区系地理分布新记录属（种）。（３）它分布于我国东部中亚热带向北亚热带过渡区域，是一个具亚热带性质的华东特有属。（４）其起源地可能是扬子古陆的九岭—怀玉联合地体；起源时间大约在新第三纪中新世（或更晚），是被子植物一个起源比较年轻的属，并不是起源古老的地理成分。

Monimopetalum Rehd. is a monotype genus of Celastraceae . As a rare and endangred as well as endemic plant to China, Monimopetalum Chinense Rehd. is distributed on the south bank of the mid lower Yangtse River extending from 28°30′ to 30°10N and 114°30′ to 118°10′E.This paper deals with the natural geographical environment and community character, the history of its distribution area and existing state of its distribution pattern, the time and area of its origin as well as the features of floristic geography. The results of investigation indicate that: (1) M.Chinense habituates the warm and humid climate conditions and deviated acid soil (pH5.5￣6.5) environment. It is an accompanying element in forest communities, and its distribution can be affected by some dominant elements e.g. Cunninghamia lanceolate, Pinus massoniana, Phyllostachys pubscens, Alniphyllum fortunei etc. (2) The historical evolution of its distribution area can be summarized as: continuous distribution (in the late Tertiary period)→disjunctive distribution (since the end of Tertiary period)→scattered distribution (existing state). It is a new recorded genus (species) in the floristics of Hubei province, which is a relic distribution in Tongshan county. (3) It is an endemic genus to East China with subtopical feature, which is distributed in the transition region from mid subtropics to north subtropics. (4) Monimopetalum might be originated from the conjoint terraes between Jiuling and Huaiyu in the Yangzi Paleoland. It has come into existence since the Miocene (or later), therefore, it is a relatively young genus instead of ancient one.