Waldsteinia,. . . , 
Weingertneria,. . . 
Willoughbya,. , 
Windsoria,. , 
Wistaria, . 
Wisteria, . 
Withanta,.. . 
Wolffia,,......~«”. 
Woodsia, . . . . 
Woodwardia, . 
Wulfenia, . . 
Xanthium,. F 
Xanthorrhiza,.. . . 
AXanthosoma,. . 
Xerophyllum, . 
Xolisma,.. . 
Xylopleurum, 
Ximenesta, . . 
XYRIDACEA,. . 
Xyris,. . 
Yucca, 
Zannichellia, 
Zanthoxylum, 
Zapania,..  . 
Zephyranthes, . . 
Zinnia, . 
Zizania, . 
Zizaniopsis, 
Zygadenus, 
Zygadenus, . . 
ZYGOPHYLLACEA, 
