Demystifying Osyris

Whenever we have problems we seek for an answer, an alternative, a way to find a solution. It is not different in the natural world - in fact evolution, the development of new forms and the creation of more diversity has always been triggered by the seeking for survival, outlining problems keeping a place within the ecosystem. During this constant seek, many plants cannot find their place, happening to die and get extinct, some others evolve exploring the resources available.

Parasitic plants are an example that there are no rules for survival in the wild, and obstacles are sometimes to be solved with extreme solutions. Parasitizing others is not the fairest solution, after all the resources used here are robbed and were meant to be used by their hosts, but it was the way these plants found to avoid death and keep on spreading their genes.

There is no particular reason, but I want to talk about Osyris (Santalaceae) this time, simply because I want to share it with you all. It is not an extravagant plant, and neither are their flowers, it is way discrete essentially because it is a hemi-parasitic plant, meaning they are green too as they do photosynthesize. When I learnt the name of this genus, I thought: “Hum, must be related with Osiris, the Egyptian God of the Death, maybe because it is a parasitic plant, and “sucks” the life of other plants”. Well, it could be a good theory in fact, but it was only another contribute from my imagination. The name Osyris is derived from the Greek ozos, meaning branched, relating to the habit of the plant, instead of what I was considering to be the horrific slayer peculiarities of Osyris.

Osiris, the Egyptian God of the Dead was originally a God of Nature, symbolizing the cycle of vegetation

It is hard to describe a typical flower of Osyris, you can find either unisexual (when sex is separated in different flowers) or bisexual, but it is not uncommon in Osyris to find remains of the opposite sex in the flowers. Even though the flowers are very tiny and not showy at all, they have their strategies to seduce pollinators to visit their flowers. Actually, male flowers might have too many distractions; they offer everything to their visitors! The pollinator who decides to come can drink the nectar and taste pollen and staminal hairs.

Male flowers of Osyris alba.
The male flowers of Osyris are grouped in cymes. Please note that these flowers don't have calyx! (Photos: Gianluca Nicolella; Sarah Gregg)

A true feast, and the feast offered by the male flowers contrasts with the stingy female flowers. They have nothing to offer, except three modified yellow anthers (of course without viable pollen), providing only the visual stimulus for the pollinator. So it seems that the female flowers lead pollinators to deception by mimicking male flowers with those “fake” anthers.

Female flower of Osyris alba.
Contrasting with the male flower, the female flower of Osyris are solitary, surrounded by protective bracts. Please note that these flowers don't have calyx! (Photo: Salvador Tello; http://www.flickr.com/photos/salvador_tello/)

But of course there is a reason for everything, and it is not only for being niggard that the female flowers don’t offer proper meals to their tireless pollinators. It is all part of the strategy, this way the pollinators are encouraged to visit all the flowers, some don’t have anything to offer, but they have to go there and check what is there available to drink and eat. Others have a lot of sweets, and this stimulates the little visitors to keep on searching for more from flower to flower, spreading the pollen. It sounds like a good strategy!