印度蒿苣族（菊科）植物之歧異度、生態及分佈

Diversity, Ecology and Distribution of Indian Lactuceae (Asteraceae)

本文探討印度萵苣族植物（菊科）之歧異度、生態及分布。印度有萵苣族植物十屬八十個分類群，十個屬分別為Lactuca. L（萵苣屬）、Prenanthes L.（福王草屬）、Launaea Cass.（栓果菊屬）、Sonchus L.（苦苣菜屬）、Reichardia Roth、Cicerbita Wallr.（岩參屬）、lxeris Cass.（苦藚菜）、Chondrilla L.（粉苞苣屬）、Dubyaea DC.（厚喙菊屬）、Youngia Cass.（黃鵪菜屬）。其中9屬51群產于西喜瑪拉雅區，7屬31群東喜瑪拉雅，5屬12群來自Ghats東、西區，另有6屬的群分佈於Gangetic平原、Rajasthan、及印度其他地區。印度的萵苣族植物其棲地即展現相當大的多樣性，由海岸至海拔5000公尺皆有分佈，且其種間和種內的歧異度極大。萵苣族的歧異及分佈中心在喜瑪拉雅地區，然後是西Ghats區及Gangetic平原區。在遺傳層次上，萵苣屬具最大歧異度分化，有25個分類群，其次是黃鵪菜屬和岩參屬；三者在喜瑪拉雅皆佔優勢。具有9個種的厚喙菊屬是中國，喜瑪拉雅地區之固有屬，其中6種在本區更是高度地域性的。萵苣族在喜瑪拉雅地區之所以具有最大歧異度，主要原因是氣候及海拔高度之多樣性變化，致使其棲地亦多變化。萵苣族可於多種棲地存活並展現其不同種的族群中大量的變異。由萵苣族的分佈分析得知，主要分佈地是喜瑪拉雅地區，在東、西Ghats及Gangetic平原則不具代表性。

The present communication deals with diversity, ecology and distribution of Indian Lactuceae (Asteraceae) which is represented by 10 genera namely Lactuca L., Prenanthes L., Launaea Cass., Sonchus L., Reichardia Roth, Cicerbita Wallr., Ixeris Cass., Chondrilla L., Dubyaea DC. and Youngia Cass., with 80 taxa in India. Among these 9 genera and 51 taxa are from the Western Himalaya, 7 genera and 31 taxa from Eastern Himalaya, 5 genera and 12 taxa from Western and Eastern Ghats and 6 genera and 15 taxa from Gangetic plains, Rajasthan and other parts of the country. The Lactuceae exhibit wide range of variations in its ecological habitats from sea coast to 5000 m in elevations and exhibit enormous diversity both intraspecifically and interspecifically. The Himalayas arc shown to be a major centre for Lactuceae diversity and distribution followed by Western Ghats and Gangetic plains. At generic level Lactuca exhibits maximum diversity with 25 species followed by Youngia and Cicerbita, all three are predominantly Himalayan. The genus Dubyaea is endemic to Sino-Himalayan region with 9 species, while 6 of its 9 species are highly localized in this region. The maximum diversity of Lactuceae in the Himalaya is due to a variety of climatic conditions and altitudes which in turn has resulted in diverse habitats. The Lactuceae inhabit, every conceivable habitats and reveals a great amount of variation in the populations of different species. The distribution analysis of Lactuceae reveals that its members are chiefly distributed in the Himalaya and poorly represented in Western Ghats, Eastern Ghats and Gangetic plains.