Dehiscent Fruits

Fig. 1   Arbus precatorius seedpods in watercolor.

 It is a plant that grows as a weed in the coastal areas of my hometown in the Philippines.
And for the sake of nostalgia, I decided to draw it based on a picture I saw on the internet.

One the subjects I have enjoyed painting recently have been some dehiscent fruits.  These are the fruits that split-open at maturity to reveal or release the seeds in them.  Dehiscence is nature's seed dispersal mechanism.

Sometimes as gardeners we seem to be focused on the flowers especially on ornamental plants such as the Fortnight Lily (Dietes iridioides).  However as a plant scientist, I seem to be more fascinated by the inherent ultimate purpose of the plant which is reproduction.  Flowers are mainly there to facilitate the seed production.  It is for this very reason that the petalss are not very lasting - they fade right after pollination.  The fruits which contain the seeds are the true star of the whole show.

Fig. 2  Dietes iridiodes seedpods in watercolor.

Commonly known as Fortnight Lily, it is a popular choice for the local landscapes because of its heat and drought tolerance. It has beautiful white flowers that bloom in waves from spring to fall.  After the petals fade away, prominent green seedpods take the place of the flowers.  However, during this time of year blackish-gray cracked seedpods hover over the evergreen leaves.

HortiCOOLture - Designed for Dispersion

Bitter Melon fruits are dehiscent - they crack open when ripe.

Plants continually amaze me.  The designer of life, I personally believe it to be God, made sure that each one is uniquely equipped with everything it needs to succeed.  For plants, success means to be able to reproduce their kind.  They photosynthesize and grow in order to flower.  Flowers eventually turn into fruits.  Fruits bear the seeds.  The seeds are dispersed to begin a new life.  And the cycle goes on.  Unlike other organisms plants do not have the mobility that would facilitate dispersal of seeds.  Nonetheless, plants have the ability to lure other life forms and the environment into scattering their seeds.  In the wild world where cultivation is not an option, plant seeds are dispersed by animals, wind, and water.

Case Example
Bitter melon (Momordica charantia L.), a member of the Cucurbitaceae family, produces fruits that are characteristically bitter.  Unaided, this unpalatable plant has a chance to grow only on the same place over and over again.  That would be a losing proposition.  But this plant is equipped with a mechanism that compensates for the bitterness of its fruit.  First of all, this plant is equipped with dehiscent fruits.  Dehiscent fruits are those that split open at maturity.  Most plants in the Cucurbitaceae family produce fruits called pepo with thick rind like that of the watermelon, pumpkin, and cucumber - they are indehiscent fruits.   But the bitter melon is one of the rare exceptions.  The fruits crack at maturity.  Secondly, as the fruit opens, the seeds that are encased in sweet red membrane are revealed to the rest of the world inviting all to come and have a taste.  Animals cannot resist the succulent and sweet seed-covering but they leave the seeds elsewhere.  At this point, seed dispersal is complete.

Have you observed any special plant features that aid seed dispersal lately?