1. Hardy deciduous vine having large leaves and flowers with the calyx tube curved like the bowl of a pipe
   - Dutchman's-pipe, pipe vine, Aristolochia durior

Type of: Aristolochia clematitis, birthwort

• Xanthorroea
• xanthosis
• Xanthosoma
• Xanthosoma atrovirens
• Xanthosoma sagittifolium
• xanthous
• Xantusiidae
• Xavier
• xc
• xci
• xcii
• xciii
• xciv
• xcl
• xcv
• xcvi
• xcvii
• xcviii
• Xe
• xebec
• Xenarthra
• xenia
• xenial
• Xenicidae
• Xenicus