Dear Readers, when my friend A delivered this to me on Friday I was puzzled. What the hell is this? It was growing on my friend’s ivy, and where there should have been a flowerhead there was this bunch of little leaflets, probably close to a hundred in total. At the time I couldn’t remember the name for this phenomenon, but then it occurred to me, and a very fine word it is indeed.
Phyllody occurs when the flower of a plant is replaced by leafy tissue . Also known as phyllomorphy or (an even better word in my view) frondescence. It was first identified by the poet Goethe, who guessed that the structures that create leaves and flowers are essentially the same, and that at some point the plant ‘chooses’ which to make. Occasionally this goes wrong, usually as a result of damage at the tip of the growing stem – it can be caused by everything from bacteria, viruses and insect damage to frost or drought conditions, though if the condition is caused by environmental conditions it will usually right itself. Some insects, in particular leafhoppers, can transmit the bacteria that cause phyllody.
However, humans being humans we have found some variations on phyllody that we actually like, and have bred for these characteristics. The ancient Chinese had a passion for roses, and developed a form of Rosa chinensis called Viridiflora, where the petals on the flowers are replaced by leaves to give a ‘green’ rose.
Interestingly, according to the RHS strawberries can be particularly prone to phyllody, with the tiny seeds on the fruit turning into leaves instead of luscious red fruit. In strawberries the damage is often caused by a bacteria, but weedkillers can also cause abnormal growth, in particular glyphosate. Lordy people, why the hecky-deck would anyone spray such a biocide close to their food? One variety, Malwina, can sometimes be hit with what the RHS calls ‘genetic fail’, when all the fruit in the first year is replaced by leaves (very frustrating I’d imagine). Strangely, the plant is said to produce normal fruit in subsequent years. If anyone has experience of this I would love to know all the details, it sounds most peculiar to me.
Phyllody is often found in members of the bean, rose and daisy families, but I can’t find any mention of it on ivy before. The specimen that I have is showing some signs of aphid or mite damage, so maybe one of these little lovelies has transmitted some kind of bacterial disease. It will be very interesting to see if this is a one-off on a few buds, or if it affects the ivy next year. I shall wait with bated breath.
Photo One By Obsidian Soul – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=22581891