Scirpus rubricosus

I have become increasingly aware and concerned about what appears to be a distinct species that is largely ignored/lumped in recent literature and completely unknown to most botanists. Several years ago when I first started working in wetland communities I was introduced to Scirpus cyperinus and its fitting misnomer “wool grass” (why not “wool sedge”?). Initially this was an easy species to recognize since it differed from other Midwestern Scirpus in having the following combination of morphological characters; average height of nearly two meters, folded (V-shaped) leaves (as opposed to the pleated M-shaped leaves of S. atrovirens), large diffuse inflorescences and achenes subtended with very long flocculent bristles that give the mature inflorescence a woolly appearance. And life was good……until I started to notice that there was something wrong. There appeared to be two very different morphologies within what I was calling S. cyperinus. Here they are side by side:

The photo on the left is typical S. cyperinus. The plant on the right is what used to be called S. rubricosus (or at least S. cyperinus var. rubricosus). The few authors that even bother mentioning both entities describe how most of the individual spikes of S. cyperinus are sessile or nearly so while those of S. rubricosus are often long pedunculate (but a few can also be sessile). Here is a close up of each (S. cyperinus on top; S. rubricosus on bottom);

And that’s it. Most also say that there is too much intermediacy to recognize S. rubricosus even at the varietal level. I have seen both of these entities in the field numerous times throughout the Midwest and have never had the slightest difficulty distinguishing them. That being said, I have also reviewed nearly 100 herbarium sheets and found this practice to be much more tenuous because something is lost in the pressing process. But what? Architecture. Here is the first photo again:

Notice the major difference in architecture between these two. Scirpus cyperinus (left) is broccolini-like or maybe like an elm tree festooned with pompoms. Notice also how the base of the inflorescence is somewhat obscured by the inflorescence. Now compare to S. rubricosus(right). Notice first how much larger it is. This is consistent. Now notice how the branches of the inflorescence fountain to one side and droop conspicuously. This is also very consistent. Lastly notice how leggy and conspicuous the long basal branches of the inflorescence are. When these characters are zoned in on in the herbarium you can sort a hundred of these things into two clean piles in a matter of minutes.

Interestingly, both often grow sympatrically. In such cases, armed with the architectural difference, one can stand and identify them from many meters away. It becomes a fun game where you check the sessile/pedunculate spikes to see how you did. Do this and you will quickly find that these two are as distinct as an elephant is from and elephant seal.

I have not noticed any ecological difference between the two. That being said, S. cyperinus is the only one I see in wet depressions in agricultural fields and is the most common one I see in road ditches. However, I have seen S. rubricosus in pretty degraded wetlands.

One more thing; there is a much more conservative and uncommon species, at least uncommon in the central and southern Midwest, that looks like these two. Scirpus pedicellatus differs in having pretty much all the spikes pedunculate, the scales are lighter brown in coloration and it fruits a month earlier. Architecturally it is very much like S. rubricosus. I collected dates off of 41 specimens at the Missouri Botanical Garden herbarium and found the following:

Species Phenology(bloom to fruit) Average

S. cyperinus June 25 to September 16 mid-August

S. rubricosus July 1 to October 7 mid-August

S. pedicellatus July 3 to August 5 mid-July

Keep an eye out for this one!

Dichanthelium werneri

Like many eager Sasquatch documentarians before me, I feel compelled to share a video of an organism whose existence is denied by the scientific community. If you know Dichanthelium linearifolium, this creature should look different to you for reasons I point out in the video.

Dichanthelium werneri had a brief but glorious history as a species until an uncharacteristically brash M.L. Fernald (1934) sunk it as a variety of D. linearifolium. I usually enjoy Fernald's take on botanical matters, but he really stepped over the limits of decency in his dealings with Panic Grasses. Many modern workers have buried it completely, largely based on Fernald's inertia I fear. With the exception of the treatment found in Hitchcock and Chase's "North American Species of Panicum" (from 1910), everyone says it is just a glabrous version of D. linearifolium. However, Hitchcock and Chase explain that the type specimen is in fact pubescent on the nodes and that this solid species more closely resembles D. depauperatum for many characters.

I wholeheartedly agree with them and in fact, once I began noticing the habit and vegetative differences between D. linearifolium and D. depauperatum, D. werneri emerged from the mist of crypticism. I see nearly glabrous plants occasionally but most plants are quite pubescent on the internodes and sheaths. I also see glabrous examples D. linearifolium that are not D. werneri, which further confuses the matter. The current placement of this amazing little grass really is a shame. Were I not bound by the economic realities of life, I would devote my time to rectifying it immediately.

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Fernald, M.L. 1934. Realignments in the Genus Panicum. Rhodora 36(#423).

Hitchcock, A.S. and A. Chase. 1910. North American Species of Panicum. Contributions from the National Herbarium vol. 15

Tragia ramosa: the spicy side of tactility

Ouch! Great Oden’s Raven!

This is what I exclaim moments before I locate Tragia ramosa while fingering my way through a quadrat or as I sit for lunch in an open glade with a view and decide to lay back and reflect. The nasty needlish and nettle-like hairs of this gangly dweller of grassland understories deftly prick the skin and give you a dose of hot proteinaceous exudate that, tingling as it burns, lasts for hours after the encounter. Try to avoid it as I may, I become hostage to Tragia’s maniacal “gotcha” game time and time again.

That being said, I am a big fan. It just has that lovable bulldoggish quality to it. And the fruits, how amazing are those bristly gynophorous brutes?

The complexity of Tragia’s pain delivery system is fascinating and has been intimately studied and explained by Thurston (1976). As explained by Thurston, each stinging “hair” is made up of four cells. Three of these cells are parallel to each other in an elongate fashion. The base of the triad is anchored to the leaf surface. The tips of the three cells converge around a terminal cell which is heavily vacuolated with stinging fluid. Protruding from the cell wall of the terminal “poison” cell is a fierce calcium oxalate crystal. But this is no ordinary crystal. The base of the crystal has several spikes that intrude into the interior of the terminal cell. The shaft of the crystal has a longitudinal groove all the way to the ice pick tip. The theory is that the slightest contact with the crystal causes the spikes at the base to rupture the vacuole and cytoplasm of the “poison” cell and the toxic brew is instantaneously funneled (or shot depending on the role of turgor pressure) into the skin of the offending beast. Tragia ramosa is covered with hundreds of thousands of such trigger happy hairs.

So where can those hungry for pain, those lusting for the spicy side of tactility experience this sneaky deterrent to sampler and grazer alike? Primarily a species of southwestern North America, Tragia ramosa enters the southern third of the Tallgrass Prairie Ecoregion at the northeastern extension of its range (BONAP). Here its range overlaps the similar Tragia betonicifolia.

In the photo above, taken at Tallgrass Prairie Preserve in the Flint Hills of Kansas, T. betonicifolia is on the left and T. ramosa on the right. Tragia betonicifolia has larger leaves on the lower half of the stem. These leaves are noticeably cordate as opposed to the nearly truncate leaf bases of T. ramosa. Also, the upper stem leaves of T. ramosa are narrower, thicker, hairier and more corrugated than those of T. betonicifolia.

So, be careful. Its dangerous out there. But if you find yourself face to face with a Tragia, feel free to give it a try. Chances are, it will find you first.

Thurston E.L. 1976. Morphology, fine structure and ontogeny of the stinging emergence of Tragia ramosa and T. saxicola (Euphorbiaceae). American Journal of Botany 63(6) 710-718.