2. About 15 species:
temperate Asia, Europe; one European species introduced in North America; one species in China.
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大约15种:温带的亚洲,欧洲;一种欧洲的种被引进北美洲;在中国的一种。
3. About 400 species: mostly tropical and subtropical, few in
temperate Asia, Africa, and America; 34 species in China.
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大约400种:在温带的亚洲,非洲和美国主要热带和亚热带,很少;中国有34种。