HORTSCIENCE 40(6):1612–1619. 2005. have played an important role in world horti- culture and have been introduced to Western countries where they have been widely cul- Endemic Wild Ornamental Plants tivated. Some of the best known examples include Rhododendron, Primula, Gentiana, from Northwestern Yunnan, China Pedicularis, and Saussurea, which are all im- 1 portant genera in northwestern Yunnan (Chen Xiao-Xian Li and Zhe-Kun Zhou et al., 1989; Feng, 1983; Guan et al., 1998; Hu, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, P.R. 1990; Shi and Jin, 1999; Yang, 1956;). Many of China 650204 these ornamental species are endemic to small areas of northwestern Yunnan (e.g., Rhododen- Additional index words. horticultural potential dron russatum), therefore, their cultivation not Abstract. Northwestern Yunnan is situated in the southern part of the Hengduan Mountains, only provides for potential sources of income which is a complex and varied natural environment. Consequently, this region supports a generation, but also offers a potential form of great diversity of endemic plants. Using fi eld investigation in combination with analysis conservation management: these plants can of relevant literature and available data, this paper presents a regional ethnobotanical be used directly for their ornamental plant study of this area. Results indicated that northwestern Yunnan has an abundance of wild value or as genetic resources for plant breed- ornamental plants: this study identifi ed 262 endemic species (belonging to 64 genera and ing programs. The aims of current paper are 28 families) with potential ornamental value. The distinguishing features of these wild to describe the unique fl ora of northwestern plants, their characteristics and habitats are analyzed; the ornamental potential of most Yunnan and provide detailed information of plants stems from their wildfl owers, but some species also have ornamental fruits and those resources, in terms of their potential foliage. Among the endemic genera, Pedicularis and Rhododendron have particularly horticultural value as ornamental species. high numbers of ornamental wild species, while Aconitum, Gentiana, Corydalis, Silene, Delphinium, Cremanthodium, and Saussurea also contain signifi cant numbers of wild or- General Study Area namental species. It is suggested that cultivation of these species may be benefi cial, both commercially and to help conserve endangered endemic plant species. Northwestern Yunnan (lat. 25°30'–29°15'N and long. 98 °05'–101°15' E) is on the Yunnan- Northwestern Yunnan, in southwestern extends up to the southeastern edge of the Ti- Guizhou Plateau in southwestern China (Fig. China is a diverse region that is internationally betan Plateau (Mittermeier et al., 2004). Within 1). To the west the region merges into the recognized as biodiversity hotspot and a center the Hengduan Mountains more than 7,000 Himalayan mountain ranges, to the north onto of plant diversity (Davis et al., 1995; Li, 1994; vascular plant species (incorporating 1,467 the Tibetan Plateau, while the south borders the Mittermeier et al., 2004). Bordering the Tibetan genera and 985 families) have been recorded. temperate and subtropical lowlands of central Plateau and northern Myanmar, northwestern Among these, 5,079 species are endemic to and southern Yunnan. This mountainous region Yunnan contains a diversity of vegetation China, 2,988 to the Hengduan Mountains, and forms the upper reaches of three major river zones spanning subtropical to alpine. As a 910 are only found in northwestern Yunnan systems, the Nu Jiang (Salween River), the result of these unique habitats and its loca- (with 13 genera containing 10 or more endemic Lancang (Mekong), and the Jinsha Jiang (the tion, northwestern Yunnan is characterized by species) (Chinese Academy of Science, 1993, upper reach of the Yangtze River). A wide exceedingly high levels of species endemism 1994; Fang, 1993; Li and Li, 1993; Wu and range of vegetation types exists including, and harbors an exceptionally high number of Ding, 1998). grassland, cushion-like alpine grasslands, rare and vulnerable species. Given the rich diversity, it is not surprising evergreen broadleaf forest, mixed forest, al- The variety of habitats in northwestern that montane plants of northwestern Yunnan pine mosaic, deciduous broadleaf forest and Yunnan stems from unique landscape features: the region is comprised of rugged, parallel mountain ranges (with glaciated peaks ex- ceeding 6,500 m) and deep gorges (down to altitudes of 600 m). The mountain ranges provide dispersal corridors for upland fl ora from the Tibetan Plateau to the northwest and the Sichuan Highlands to the northeast, while the river valleys are conduits for fl ora from the Indo-Malayan and east Asian lowlands to the southwest and southeast (Sun, 2002). However, the same mountain ranges and gorges that have allowed adjacent fl oras to overlap, have also maintained suffi cient isolation between valleys to enable signifi cant in situ evolution. Northwestern Yunnan is part of the Moun- tains of Southwest China Biodiversity Hotspot, which includes the Hengduan, Gaoligong, and Nu Shan mountains of western Yunnan, and Received for publication 4 Apr. 2005. Accepted for publication 14 May 2005. Supported by the Natural Science Foundation of Yunnan (grant 2001C0010Z) and the National Key Basic Research Program (973) (grant 2003CB415102). We extend a special thanks to David Melick and Allen Coombes for improving English writing and also for the comments and sug- gestions and Chen Wen-Yun for his help during the establishment of the database. Z.-K. Zhou appreciates support from JSPS. 1Author for correspondence; e-mail: zhouzk@ mail. kib.ac.cn. Fig. 1. The study area, northwestern Yunnan of China. 1612 HORTSCIENCE VOL. 40(6) OCTOBER 2005 8884-Feature.indd84-Feature.indd 11612612 99/28/05/28/05 111:06:071:06:07 AAMM FEATURES Table 1. The families and genera in order of numbers of endemic wild fl ower species. known as the treeline, to a treeless vegetation. Family No. of species Genera No.of species Above the treeline is the true alpine zone where Ranunculaceae 39 Pedicularis 34 the vegetation is primarily dwarfed shrubs and Scrophulariaceae 34 Rhododendron 31 ground hugging herbs, with no trees. Ericaceae 32 Aconitum 23 The growth habit also helps in surviving Compositae 18 Gentiana 16 freezing temperatures: cushion and rosette Gentianaceae 16 Corydalis 16 herbs may be 10 °C higher than the surround- Rosaceae 14 Silene 13 ing air. Caryophyllaceae 13 Delphinium 12 Analysis of ornamental features. Ornamen- Fumariaceae 13 Cremanthodium 8 tal plants can be divided into three main types: Primulaceae 11 Saussurea 8 those with ornamental fl owers, ornamental temperate conifer forest (Wu and Zhu, 1987; ing distribution patterns, life form, vegetation fruits, or ornamental foliage. However, many Yang, 1990). types, fl ower colors, fl owering season and wild plants have several ornamental parts, The elevations of lower hill areas and ornamental value. Using this database, we therefore, these divisions serve to distinguish valley plains along the Jinsha, Lancang and identifi ed those endemic species that had or- different groups on their primary ornamental Nujiang, range between about 700 and 1,100 m. namental value. Evaluation and reinvestigation features. However, the taller mountains, such as Yulong, of this list of endemic plants from northwestern The results show that of the endemic or- Haba and Meili snow mountains exceed heights Yunnan was based on literature, herbarium namental plants in northwestern Yunnan, 235 of 5,000 m. The average temperature in this records, the database and fi eld work. species have ornamental fl owers, and most region is 10 to 15 °C, the highest and lowest Defi nition of ornamental plants. Different of them belong to the families Ericaceae, temperatures in the ranges of 30 to 37 °C and botanist have different defi nitions of orna- Compositae, Liliaceae, Orchidaceae, Ranun- –4 to –12 °C, respectively. The annual aver- mental plants. In this study, we consider wild culaceae, Rosaceae, and Gentianaceae. Flower age rainfall is between 1,185 and 1,439 mm ornamental plants to be those which occur colors vary from red and purple to white and (Yang, 1990). naturally in the fi eld and have highly orna- yellow. The red-fl owered plants include some Site selection. Northwestern Yunnan covers mental features such as ornamental fl owers, species of the genus Pedicularis, such as P. 16 counties of Diqing, Lijiang, Nujiang, and fruit, or foliage. habachanensis, P. praeruptorum; the genus Dali Prefectures, lat. 25°30'–29°15'N, and long. Rhododendron, such as R. cyanocarpum, R. 98°05'–101°15'E. Its total area is 68,908 km2 Results and Discussion fastigiatum, R. codonanthum; and the genus (17.5% of Yunnan Province). Androsace, such as A. alchemilloides. Most of Sites were selected according to the physi- Wild ornamental plants endemic to north- the purple-fl owered plants belong to the genera cogeographical regionalization parameters western Yunnan. In total, northwestern Yunnan Gentiana, Primula, Aconitum, Delphinium, and outlined by Yang (1990) which are comprehen- contains 2,206 species, (belonging to 324 Corydalis (exemplifi ed by species such as G. sive contributions about physicogeographical genera and 38 families), of which 910 species bella, P. annulata, A. acutisculum, D. brevise- regionalization of Yunnan. We used six areas: (41%) are endemic (Li et al., 2003). There are palum, and C. petrophila). White-fl owered Yunlong, Lanping alpine-medium hillside area a total of nine endemic families with more species include Sorbus harrowiana, Spiraea (15,000 km2), Nu Jiang alpine mountains and than eight endemic species. A considerable calcicola, Anemone multilobulata, prominent gorge area (10,000 km2), Dali and Lijiang number of these endemic species were found yellow-green fl owers include Rhododendron basin and alpine-medium coteau area (26,000 to be wild fl owers: we identifi ed 262 species, dendricola, R. rhombifolium, Pedicularis km2), Jinsha Jiang river valley area (15,000 belonging to 64 genera and 28 families endemic lecomtei, and P.