世界鸭跖草科植物属的分类与分布

The classification of genes and geographical distribution of world Commelinaceae

鸭跖草科植物属单子叶植物,一年生或多年生草本。茎有节,直立或披散,偶有攀援;叶互生有鞘;花序顶生或腋生,成丛或为聚伞花序、圆锥花序;花两性,辐射或两侧对称,通常蓝色;花被6,萼片3,花瓣3,有时下部合生成管;雄蕊6,能育或3个退化,花丝有时被念珠状毛;子房上位,2-3室,每室有胚珠1;蒴果,开裂或不裂;种子小有假种皮;胚乳丰富。本科植物40属500种,分布热带,亚热带,少数达暖温带地区。我国连同栽培15属53种,各地皆有分布,主要在东南部地区。

The Commelinaceae belongs to the Monocotyledons. Terrestrial or rarely aquatic herbs. Roots adventitions,fibrous. Stem usually rhizomatous,branched,succulent,notes often swollen,erect or prostrate. Leaves rarely radical,usually cauline and ramal,exstipulate,sessile,alternate,single,ertire,ovate-lanceolate or linear,leaf base sheathing,venation parallei. Inflorescens monochasial cyme,generally a cincinus. Flowers bisexal or polygamous,somewhat zygomorphic,hypogynous often enclosed in a spathe. Perianth segments 6（ 3 ＋ 3）,in two series： outer sepaloid and inner petaloid. 1 of the three petals in many genera reduced to a scale. Stamens 6 all perfect or some sterile and rperesented by staminodes,filaments often bearded with moniliform heirs. Carpele 3 pistal syncarpous,ovary superior,trilocular： sometime one locule may be abortive,ovules solitary or few,placantation axilc. Fruit a capsule or nut. Seeds angled,endospermic,embryo small,situated beneath a discover like callosity on the seed coat.The family is spread over 40 genera and 500 species. The plants are distributed throughout the tripical and subtropical regions. In China the family is repersented by 15 genera and 53 species.The family is of little econmic value. The species of Commelina Tradescantia Flocope and Rhoeo are cultivated for ornamental flowers and Zebrina for the striped leaves.