1. Of northern Europe and America; resembling a miniature fir
   - mountain clubmoss, little clubmoss, Lycopodium selago

Type of: club moss, club-moss, lycopod

• genus Wynnea
• genus Xanthium
• genus Xanthomonas
• genus Xanthorroea
• genus Xanthosoma
• genus Xenicus
• genus Xenopus
• genus Xenorhyncus
• genus Xenosaurus
• genus Xeranthemum
• genus Xerobates
• genus Xerophyllum
• genus Xiphias
• genus Xylaria
• genus Xylocopa
• genus Xylomelum
• genus Xylopia
• genus Xylosma
• genus Xyphophorus
• genus Xyris
• genus Yucca
• genus Zaglossus
• genus Zalophus
• genus Zamia
• genus Zannichellia