YAM TRIBE. 



605 



TAMUS coMMtfNis (Black Bryony). 



1. TAMUS (Black Bryony). 



1. T. communis (Black Bryony). The only British 

 species. Root a large, solid tuber, black externally ; stem 

 slender, twining among bushes to the length of many 

 feet, and clothed with numerous varnished, heart-shaped 

 leaves, and clusters of small, green flowers, which are 

 succeeded by elliptical scarlet berries. The leaves are 

 reticulated with veins somewhat like those of Dicotyle- 

 donous plants, but they are not jointed to the stem. 

 Late in autumn they turn dark purple or bright yellow, 



