The Urban Pantheist

The plant is a black cherry Prunus serotina, a weedy little tree found throughout the New World. The leaf bears the mushroom-like galls of a tiny arachnid, the mite Eriophyes cerasicrumena. The animals are living inside the protuberance.

The white discoloration patterns on the leaf are feeding marks left by leafhoppers--small (but enormous compared to the mites) insects that puncture the leaf and feed on the fluid within.

Thanks always to Charley Eiseman, who expertly divines animals from the marks they make on plants. He rears galls to identify the adult insects--I think he has discovered new or locally unknown species doing this.

This mysterious and perhaps a little creepy stone cabin welcomes you to the south entrance of Cutler Park. The northern end is far more developed and well traveled, and I have never been there.

( come along for a lot of pictures )

Frankly, I'd never heard of the hackberry tree Celtis occidentalis* before my first encounter with the hackberry nipple gall. I think we can agree that's one of the most wonderful word combinations I've placed here. The galls are made by aphid-like insects called psyllids, in the genus Pachypsylla, including notably Pachypsylla celtidismamma.** The galls also harbor some non-gallmaking psyllids who benefit from their relatives' alteration of the hackberry leaf.


*Western hackberry

**Hackberry breast thick flea

The far back corner of Contentment Cottage's yard is full of a low creeping mint that bears purple flowers and little fruits that look like testicles. The plant is ground ivy, or "creeping Charley" Glechoma hederacea* and the little ball bags are galls that protect tiny wasp larvae.

Both the plant and the wasp Liposthenes glechomae** are Old World species. The plant, like many mints, has a long history of culinary and quasi-medical uses. It grows well in shady yards that get mowed fairly infrequently, but is sometimes grown as a potted plant. Europeans brought the plant with them to New England, and the plant brought the wasp.



* "Glechoma"is a reference to Pennyroyal, a related plant, while "hederacea" implies that it is in the ivy family, a biological lie.

** I'm going out further on a limb than I usually do with this one, and that's saying something. "Liposthenes" seems to mean "fat palms (of the hands)" which has to be wrong--this wasp has fat parts, but not its hands. "Glechomae" refers to the wasp's relationship to genus Glechoma.

I canceled February's walk on account of we had more snow on the ground than any other time in history, and I didn't feel like walking through it more than I already was. We had a fair amount of melt in late March, and I was feeling good about seeing what creatures were out on the last Sunday of the month. Then on the Saturday before, it snowed again. In the Blue Hills, where the walk was planned, they got about 3 more inches. A friend and once-frequent Urban Nature Walker was going to be working at a maple sugar festival at Brookwood Farm in the Blue Hills, so that's where we went.

Above you can see the grounds of Houghton's Pond Recreation Area, complete with fresh blanket of snow and incongruent obsolete technology. We parked here and took a shuttle bus to the farm.



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Despite the dry conditions, there was a bloom of reishi mushrooms coming from subterranean roots

Urban Nature Walk returns to the Riverway, on a quest to reach Ward's Pond, the spring that gives it water. I quickly got over doing an UNW on a Saturday (I have a mushroom class tomorrow) and met up with the group by the Longwood T stop. The first three to show up all brought gigantic cameras, so I will look forward to seeing their pictures, and linking you to them as well.

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At the end of the last Urban Nature Walk my friend dedhamoutdoors suggested we walk near Little Wigwam Pond (this is pronounced "little wiggum pond" in order to differentiate locals from carpetbaggers). A couple days later she said she found sundew plants there, and I said "sounds good! you're leading!" or words to that effect.

This first picture shows the group exploring life along the train tracks.

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I'd like to mark all the corners of the year with visits to places that fill me with the awe of nature. It might not always be possible, and honestly I wasn't even thinking of the date when I decided to bring Charlie to Cutler Park--it was just warm.

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Ground Ivy (Also Creeping Charlie, Gill-Over-the-Ground) Glechoma hederacea

"You know that viney weed with the scalloped-edged leaves that takes over your yard? That one that you can tell is a long, climbing thing, but when you try to rip it out of your flower beds, just the part in your hands breaks off instead of pulling up the whole thing? The one that gets those pretty little purple flowers in the spring? Turns out Europeans brought it here on purpose, just like garlic mustard. It's a salad green. You can use it in soups. You can make tea out of it. The Saxons used to use it like hops in beer. It has medicinal properties. A 1986 study found it inhibits EBV and skin tumors. It's part of the mint family, and mints were traditionally used as all-purpose antibiotics." - gigglingwizard

I don't have much to add, except that it smells really nice when you mow it. It's a common urban and suburban plant, and first joined us as 365 urban species number 118.



But what the hell is growing on it?! I was just sitting in my yard when I saw this thing. I assumed it was a small lawnmower's mushroom and went to pluck it--to my surprise I pulled out a plant with a foreign growth.



I knew that it had to be a gall, but had no idea that any creature made use of ground ivy for this purpose!


Ground Ivy Gall Wasp Liposthenes glechomae

I cut it open to see a single wormlike larva inside, very much like an oak apple gall. Wormlike larvae are usually the babies of wasps or flies, two groups known to produce galls. At least mites and pathogens were eliminated as the causal agent. I searched the index of my copy of Tracks and Sign of Insects and Other Invertebrates but ground ivy was not in the index, nor its scientific name. I posted pics here, on facebook, and on bugguide. One of the authors of the above book chimed in to identify the gall as belonging to Lisposthenes glechomae, a tiny wasp in the same family as the one that causes oak apples. He also pointed out that this gall appears in his book (p. 395--it's in the index under galls, ground ivy).

The gall protects the developing larva from predation while providing a food source for it. The insect causes little to no damage to the plant. This wasp is native to Europe, and was translocated inadvertently with its host.

This is my favorite picture from today's Urban Nature Walk in Forest Park, a huge city park in the third largest city in Massachusetts, Springfield. I grew up two towns away from here, but had never explored it quite like this. Here's my favorite picture from the walk, from about halfway through. But let's see how we got there!

( lots and lots of photos )

A great walk! If you'd like to get in on the action go here: https://www.facebook.com/groups/68443835849/