Friday, January 6, 2023

A tale of two contrasting little beauties

Inflorescence of Cynodon dactylon showing purple-pink anthers and stigmas

I have always been fascinated more by tiny species than by large showy ones. Even my brief flirtation with the Orchids shows this preference, where I gravitated towards the tiny micro-orchids like Lepanthes. This bias towards the tiny means that I am always on the lookout for Poaceae that are cute and pretty, and last week I focused on two species here in Florida that fulfilled that goal, but were otherwise quite different. 

One is a native, a tight rosette bunchgrass that prefers a shaded and moist habitat. The other is a fast spreading aggressive immigrant, a commonly encountered prolific producer of rhizomes and stolons that luxuriates in the full sun. 

The native is from a genus that I have waxed lyrical about in the past. Dichanthelium strigosum subsp. glabrescens forms a tight rosette. It's quite small, and with its dark green leaves and dark culms it is a really attractive species.

Dichanthelium strigosum subsp. glabrescens

I found specimens of it under a tree in an area with usually dry whitish sand. The tree must be giving them a shady microhabitat place to live, as well as a bit more moist ground. The species is native to the southeastern USA and parts of the Caribbean, and the subspecies is typically found in Georgia, Florida, and the West Indies. It usually lives in relatively undisturbed habitat and prefers moist sandy soil, so longleaf pine savannas would be one place to look for this.

Inflorescence of D. strigosum - even the spikelets are cute!

I must admit I was excited to see this beautiful critter under the tree. Its small size, dark culms, and dark green blades with borders made it stand out against the whitish soil and brown detritus around it. Some of the specimens also had flowerheads in bloom, the tiny spikelets marked with purple glumes and stigmas.

I must have spent an hour just looking and photographing the few specimens that I found, but I went home happy and satisfied after that brief hike and discovery.

The edges of the leaf blades of D. strigosum showing long hars

The second species that I encountered was one that I passed by almost everyday whenever I walked to the gym, but one which I had not yet seen flowering because it was kept cropped and short. There is a golf course in that path, and I have often marveled at the beautiful fine grass that adorned the tee and putting greens. I've even sometimes had the urge to take off my shoes and walk on the fine lawn - although I'm sure this would have annoyed someone just trying to play ;-)

I knew that it was Bermudagrass (Cynodon dactylon), but my attempts at photographing more than just its blades were continuously thwarted. Until, that is, I happened upon some "wild" specimens of this species nearby!

Masses of flowerheads of Cynodon dactylon

The flowerheads were gorgeous, the distinctive digitate inflorescence rising from the ground like tiny umbrellas.

C. dactylon is native outside the Americas, and is a common turf grass. Its strong rhizomes and stolons allow it to form a dense mat and makes it quite competitive against other plants. It has been shown to strongly inhibit the growth of competitors, and even though it has such fine leaves and a short stature, its roots can go extremely deep into the soil. Some studies showing it going more than 2 meters down!

 Flowerhead of Cynodon dactylon

Its inflorescence is quite distinctive, with multiple racemes (usually 4, though I also saw 5, and references note can be from 3-7) radiating out from a common point. The spikelets themselves look like a weird Pacman, or some armored reptilian head!

Dried spikelets of Cynodon dactylon under portable microscope

The two small species had such contrasting looks and lifestyles, and yet I was ecstatic at being able to photograph and see these relatively smaller specimens in full flower. 

Now, my next challenge is to find the absolutely gorgeous Sporobolus discosporus in South Africa!

Sporobolus discosporus (c) Richard Gill

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