Thursday, September 14, 2023

Life in the Cracks Part Deux (Vertical Edition)

The very first article I posted was in July 2019, when I marveled over all the varied life that existed around us without being noticed.

In that post, I highlighted Digitaria spp weeds that had sprouted up from the cracks in the parking lot of an office complex.

Life In the Cracks

I was reminded of this again while walking around a park in Broomfield, CO last month, and I noticed a wayward individual grass that had somehow germinated from an extremely narrow vertical crack going up the side of a bridge.

The base of the culm comes straight out of the narrow crack.

There were no other vegetation at all in the long crack, and given that it hadn't rained in a bit, I had to wonder how the specimen was surviving at all. The other question that sprung to my mind was how it got there in the first place, and the most likely explanation was that a wind blown seed had fond its way into the crack, and had been lucky enough to take root before it could be dislodged.

It was a Setaria sp (Setaria viridis?), members of which seem to have a proficiency when it comes to such an epiphytic lifestyle. I have seen members of this genus proliferating along walls in New Jersey as well, although none of those were in the same precarious situation as this lone Broomfield individual.

Flowerhead of the specimen

To most people, such minor miracles as this are not even noticed, or acknowledged. At most their eyes might hover fleetingly over the lone survivor, then dismiss it as just another weed and continue on.

But when I first saw this, I was amazed. Life, it seems, will always find a way. It will grow and exist if there is any way at all to do so, no matter how unusual or surprising its method. Life is persistent; it is dogged and stubborn. It will turn up in the most unexpected of places, and surprise us.

I hope I never get tired of having such feelings of amazement at the wonder of life.

ps. as an aside, the ability of members of the Poaceae to survive in what seemingly are epiphytic conditions again highlights the question of why the family does not have more real epiphytes, like the members of the Orchid and Bromeliad families. There are only a grand total of perhaps 2 grasses that are considered truly epiphytic, out of a membership of around 12,000 species. Why have grasses, which are so dominant in many other places, failed to capitalize on this niche?

The answer to the question seems to be tied to the fact that the Poaceae are mainly wind pollinated, and that such a mechanism is not optimal in the wet, humid and closed environments that are favored by true epiphytes. For more on this topic, click below:

Calling all orchid-wannabees: Where are the epiphytic grasses???

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