It appears that my intentions and reality do not mesh, yet again…a Botany Word of the Week is just simply too much for me to maintain on top of all my other projects. But I love creating these posts and I hope you enjoy reading them – so I’ll switch to a monthly format which should be far easier for me to complete. We’ll see…intentions, you know….
If you have a medical background, you’ll already know what this term means…except I’m going to use it in relationship to fruits.
When they are mature and dry enough, dry dehiscent fruit split open to release their seeds. Dehiscence is this act of breaking open at a seam. The part that splits is the pericarp (comprised of ovule-bearing structures of the flower called carpels).
The dry dehiscent fruit you are probably most familiar with belong to legumes. Peas, beans, and lentils fall into this category. They all have one carpel and if you’ve ever shelled garden peas, you’ll recognize the way that carpel splits open (except that you’re facilitating the split before it’s “supposed” to happen. When you allow peas to dry for harvesting, and they split open, then you’re letting them do their thing).
Do you remember this post I did a couple of years ago about the ‘Le Puy’ lentils I grew? What I’m describing there is the explosive way the dehiscent fruit burst open when they’re ready. And I’ll never forget the way that the seed pods of the Caragana shrubs that lined the driveway to my childhood home audibly crackled and violently burst on hot, late summer days, showering the seeds everywhere.
‘Le Puy’ lentils…not yet dry enough to split open.
Peanuts are one dehiscent legume that don’t – thankfully – burst open when dry. You have to help them along by breaking them open yourself.
There are always exceptions. Some legumes have indehiscent fruit, and their carpel does not split open when dry. If you have a honey locust growing in your yard, that’s a good example.
Legumes aren’t the only dry dehiscent fruit. There are capsules, which have more than one ovule. Lilies and poppies have capsules. There are also follicles, of which plants such as columbines have more than one. Siliques are another. These are a type of elongated fruit that kind of resemble legumes. If you’ve ever allowed your radishes to set seed, that pod you’re looking at is a silique. Just for fun, there are also silicles, which are not as long as siliques. Honestly, I’m not making this up, even if it sounds a bit giggle-inducing.
What is your favourite dry dehiscent fruit to grow?
Some links for further reading: