| Gaoligong Mountains, belonging to the important parts of Hengduan Mountains, lie in the border area between China and Myanmar, rising between the great Salween and Irrawaddy. The geographical position is 24° 56’-28°22’N,98° 08’-98° 50’ E. So far,4303 species belonging to 1086 genera in 210 family were recorded. Among them there are 1929 endemic species (including varieties), and 434 species of them endemic to Gaoligong Mountains. Rubus in Gaoligong Mountains is rich and 57 species (47 species and 10 varieties)are recorded in "Gaoligong Mountains Plants". Rubus plays an important role in Gaoligong Mountains Vegetation System. They are the dominant component of some vegetation types or pioneer plants in the process of forest succession. Besides, almost all species are edible, with important economic and scientific values. Its species circumscription is complicated by large numbers, wide distribution, hybridization, polyploidy and agamospermy, so it is very difficult to classify. In this study, Rubus in Gaoligong Mountains had been taxonomically revised based on classically morphological and phytogeographycal patterns, aiming to solve the species-delimitation criteria of Rubus and to clarify its classification and distribution. The morphological comparisons were based on specimens in herbaria and observations of wild populations. The main conclusions of this study are as follows:(1) Based on herbarium study, field observation and morphological analysis, it was confirmed that the characteristics of flowers and fruits are stable in species level and are very useful in taxonomy of Rubus in Gaoligong Mountains, and inflorescens is another useful characteristic; moreover the taxonomic value of glandular hairs, indumentum and needle is varied in different species.(2) In this study, there are 51 species and 8 varieties in Gaoligong Mountains. Among them 20 species and 4 varieties belong to Sect. Idaeobatus,22 species and 2 varieties to Sect. Malachobatus,1 species to Sect. Dalibarda,4 species to Sect. Chamaebatus,4 species and 2 varieties to Sect. Cylactiss. And the key to all taxa of Rubus in Gaoligong Mountains was presented in this paper.(3) Some of the Rubus species distributed in Gaoligong Mountains have been revised as follows:Rubus taronensis Wu ex Yii et Lu was combined into Rubus acuminatus Smith. Rubus clivicola Walker was combined into Rubus potentilloides W. E. Evans. We confirmed that Rubus laxus Focke is same of Rubus efferatus Craib produced in India and Thailand, and determined that Rubus fuscifolius Yu & Lu is endemic. Two specimens from Pingbian and Hekou(Sino-soviet Yunnan exp.3464 and Liu Weixin539) aren’t the same of the specimen citated by original authors.(4) Rubus in Gaoligong Mountains are endemic to Asia. According to the geographical distribution characteristics, The total 59 species of Rubus in Gaoligong Mountains could be divided into 5 types, namely 3 species to East Asia character; 10 species to Himalaya-South China-Southeast Asia character; 19 species endemic to Pan Himalaya; 16 species endemic to Hengduan Mountains and 11 species endemic to Gaoligong Mountains. The endemic phenomenon is obvious, and it is closely related to the flora of Himalaya.(5) The distribution of Rubus in Gaoligong Mountains is not uniform on the geographical distribution, with most numbers in the north section but little in the south. The ratio is 5.33:1,1.42:1 for the east and west sides. So the Rubus species of west slope is richer than that of east. The number of Rubus is increasing with the rise of altitude and begin to decrease at certain sea level. Most of the species are concentrated in central mountains(2000-3000m) but little in the valley area (200-2000m) and peak area (above 3000m). |
PDF Full Text Request