杨亚科植物的分类与分布

On the Classification and Distribution of the Subfamily Populoideae(Salicaceae)

杨亚科（Populoideae）植物自然分布于热带非洲和大约从北纬19°～70°度的北半球，由胡杨属（Balsamiflua）和杨属（Populus）2个属所组成。胡杨属间断分布于赤道非洲、古地中海地区和墨西哥，包含2个组（胡杨组、墨杨组）和约3个天然种。杨属分布于欧洲、亚洲、非洲（北缘）和北美洲的广大地区，包含大叶杨亚属（Subgen．Leucoides）（大叶杨组）、杨亚属（Subgen．Populus）（青杨组、黑杨组、杨组）2个亚属和约52个天然种。拟定了杨亚科属的检索表、胡杨属组和种的检索表、杨属亚属和组的检索表以及杨属中各组种的检索表。提供了一个杨树种类目录，包括它们的正名、异名、文献引注和地理分布等。

The subfamily Populoideae （Salicaceae） naturally distributes in tropical Africa and in the Northern Hemisphere from about 19° to 70° north latitude, and consists of two genera, i. e. Balsamiflua and Populus. The genus Balsamiflua, with two sections, i. e. sect. Balsamiflua et sect. Abaso and about 3 natural species, disjunctively disperses in equatorial Africa, Tethyan region and Mexico. The genus Populus contains two subgenera, i. e. subgen. Leucoides （ incl. sect. Leucoides） et subgen. Populus （ incl. sect. Tacamahaca, sect. Aigeiros et sect. Populus） and about 52 natural species, and widely ranges in Europe, Asia, North America et the northern fringe of Africa. A key to the genera of Populoideae, a key to the sections et species of Balsamiflua, a key to the subgenera et sections of Populus and the keys to the species of each section in Populus are drafted. A checklist of the poplar species is provided,including their correct names, synonyms, bibliographic references, geographic distributions etc.