Possible Clues:

• Desert plants
• Evergreen plants with tall stout stems
• Desert bloomers
• Joshua trees, e.g
• New Mexican succulents
• Desert plants with sword-shaped leaves
• ... tropical American plants
• What have they to say, back from Central America about you getting a couple of hundred?
• You get to the double century in, say, these plants from America
• Plants with sword-shaped leaves