Alderville Black Oak Savanna Bioblitz: Two Cribraria and Bovista echinella

Here’s a rare little cutie, a tiny puffball that I might never have found if I hadn’t been invited to do the mycology part of a Bioblitz this past weekend at Alderville First Nation Black Oak Savanna/Tallgrass Prairie. Located south of Rice Lake, the site holds remnants of Canada’s easternmost prairie. It’s one of the most endangered plant communities in Ontario, so even though there hadn’t been much rain recently, I was hyped about what I might find fungi-wise. 

My friend Ulli and I followed our guide, Radek Odolczyk, into the grasslands, heading first to an area that had recently undergone a prescribed burn, done to mimic the restorative grass fires that naturally occur on tallgrass prairies. Growth was sparse and the earth had been parched by a heat wave, so it wasn’t too surprising that the only things we found in this area were a couple of shrivelled, ultra-common Agrocybe pediades, and three equally desiccated fairy ring mushrooms (Marasmius oreades). Already sweating, we switched our search to a field with more established growth.

Unfortunately, there were two big problems with fungi hunting in the tallgrass area. First off, though it was barely 7 am, it was fast becoming too hot to be out in the full sun. Secondly, the ground beneath the spring grass growth was covered with an incredibly dense, crosshatched mat of last year’s grasses, (some species reach two-metre heights—hence the name “tallgrass”), a mat that was almost impossible to pull apart to see if anything of interest was growing underneath. Since the area wasn’t being particularly fruitful and no one was interested in succumbing to heatstroke, we started towards the shade of the black oak savanna. 

Bioblitz fungi hunters

The path through the grasslands had been mowed, so we walked slowly trying to spot anything that might be vaguely mushroom-like growing at our feet. While still bent over after being tricked yet again into inspecting the possible fungal whiteness of either bluebird or field sparrow droppings, we finally noticed a few mini puffballs. We bagged them and moved on. 

Black oak savanna at the Alderville site

In the black oak savannah I was excited to find hawthorn leaves showing early signs of cedar-hawthorn rust, Gymnosporangium globosum, a new one for me and closely related to the cedar-apple rust that I wrote about in my last post. It was almost as dry in the open savannah as in the open prairie, so we delved deeper into the woods. 

Gymnosporangium globosum—cedar-hawthorn rust

Though we were in much-needed shade, we were also surrounded by so much uncommonly tall and healthy poison ivy that we were essentially trapped on the path. Fortunately, though, the path was lined with logs that, unlike the ground, held enough moisture to encourage a nice variety of fungal growth, primarily loupe-worthy ascomycetes and myxomycetes. It was among this latter group that we found not one, but two “Chinese lantern” slime mold species, Cribraria cancellata and C. mirabilisa, neither of which I'd ever found before. Soon afterwards the intolerable heat and humidity (we’re Canadian, eh?) chased us back to the visitor’s centre. 

Cribraria cancellata—a "Chinese lantern" slime mold

Cribraria cancellata spores and peridium

Cribraria mirabilis is redder than C. cancellata.

Cribraria mirabilis spores and peridium

After I'd done micro of the two Cribraria at home, I took a closer look at the mini puffballs. Both samples were very small. The “big” one was a tad less than a centimeter in diameter, while the other was all of two millimeters high. That smaller, less mature one, was covered in tufted spines, while the larger, more mature one had become nearly bald.

Bovista echinella is a tiny, tufted puffball found in grasslands.

There are a few species of ground-growing diminutive puffballs out there, so I poofed a dusting of spores from the older one onto a slide and stuck it under the microscope, hoping that whatever I saw would help me narrow down my search. 

As Bovista echinella ripens, the tufted white ornamentation falls off.

Now, I’ve often been surprised by spores when I've looked through the eyepiece, but I have to say I’ve never expected to see tadpoles with twirling tails, which is what I saw this time. Of course, that’s not what they were; they were actual spores, and their “tails” were long stalks called “pedicels.” Very cool! 

Tadpole-like Bovista echinella spores have long stalks called pedicels.

I quickly found a description of a smallish species of puffball with long-pedicelled spores, Lycoperdon pedicellatum, but it wasn’t a good fit. The fruitbody of L. pedicellatum has a sterile base, which mine didn’t have, has much larger fruit bodies (up to 6 cm. tall), and the pedicels on its spores are very long—up to seven times the length of the spore, while mine were only double the length. Bovista plumbea also produces spores with pedicels, but, unlike mine, the pedicels are tapered at the ends, besides which, B. plumbea isn’t covered with tufted spines. 

And then I found the description I was looking for: pedicels twice as long as the spores; capillitium (sterile filaments mixed with the spores) sometimes branched and septate, and only as wide as the spores; fruit body tufted, and always very small—less than 1 cm in diameter. 

The capillitium of Bovista echinella can be forked
and septate and is only as wide as the spores.

My little guys are called Bovista echinella (also known as Bovistella echinella or Lycoperdon echinella). According to one source, like other true puffballs, they’re edible when still pure white inside, though they’re so small they’d only provide a side dish if one invited a mouse for dinner. What all sources seem to agree on is that they’re rare. I don’t know about that. It’s not as if they’re easy to see—unless you’re already down on your hands and knees in a field checking out fungi-mimicking bird droppings.  

References:

William Chambers Coker, John Nathaniel Couch, The Gasteromycetes of Eastern United States and Canada (as Bovistella echinella)
Mycoquebec (as Lycoperdon echinella)