孑遗种

珙桐（Davidiainvolucrata）是我国特有的珙桐科珙桐属植物，起源古老，为第三纪古热带植物区系的孑遗种。

Davidia involucrata is a species that is specially distributed in China and belongs to Davidia and Nyssaceae . It has epibiotic origin and is relic species from tertiary palae-tropical flora .

存在许多孑遗种；

There were plenty of epibiotic species ;

通过对大山峰18种珍稀濒危植物及国家保护植物区系组成的分析，得出该区系具有木本植物优势、区系起源古老、孑遗种多、地理成分复杂和特有植物多等特徵。

By analysing the composition of the flora of18 rare and endangered plants and national conservative plants in dashanfeng , showed the result that this area has characteristics of dominant woody plants , old origin , rich remaining plants , complicated distribution types and many endemic species .

四川省珍稀濒危植物区成分复杂，特有、孑遗、单种科属植物以及高山植物较多。

The compositions of the rare and endangered plants in Sichuan are complex .