Y has presented a problem, so I will cheat with a plant instead – yucca. Yuccas are American, with many from Central America. Perhaps the most famous is the Joshua tree (Yucca brevifolia) although Yucca gloriosa is the most common in UK gardens, being hardy and dramatic. Yuccas all have narrow, bayonet-like foliage but they may have upright trunks or creeping stems so the rosettes of leaves look stemless. They have showy, creamy white, bell-shaped flowers.

The genus yucca was named by Linnaeus but he got the name wrong – the name was an old Carib name for cassava (manihot) that was grown on those islands and when the first yuccas were discovered by the West he gave yuccas the wrong name since cassava is nothing to do with the plants we call yuccas.

Yuccas have a very close relationship with special moths that pollinate the flowers. The female moths have special mouthparts that enable them to collect and roll the pollen into balls which they then push onto the stigma to pollinate the flowers. Of course she doesn’t do this for the good of her health, but rather the good of her children because she then lays eggs in the ovary. The grubs then eat the developing seeds but not all of them. So the moth can be sure of having healthy offspring and the yucca can be sure to produce some healthy seeds – a win all round.

Despite what I used to think, these seed-munching larvae are not the Mexican jumping beans. I used to buy these every now and then as a child and the ‘beans’ that were curved on one side and flat on the other would move when warmed. They are the seeds of a shrub called Sebastiana pavoniana (native to Mexico) and inside the jumping beans is a larva of a moth. The larvae eat the contents of the ‘bean’ and when they fall to the ground the larvae twitch so that the ‘beans’ move from ares in sun where it is hot, into shade. That is why the beans jump when they are warm and stop when they are cool. Then the larvae pupate, ready to hatch out as an adult moth.

yucca