NOTE: It has been brought to my attention that Helvella lacunosa probably does not occur in North America, and instead we have a number of black Elfin Saddle mushrooms that are genetically distinct from Helvella lacunosa. For further information about the genetic research on black Helvellas in North America, take a look at this.
On the west coast, oak-loving black Helvellas are called Helvella dryophila, and pine-loving black Helvellas are Helvella vespertina. Thanks to Alan Rockefeller for the clarification on this matter. Yay citizen science!
In the interest of being a bit more correct, I have added these two Latin names alongside Helvella lacunosa. I did not remove the name lacunosa because most current guidebooks and materials refer to them as lacunosa. 
The Elfin Saddle mushroom, Helvella lacunosa, Helvella dryophila, and Helvella vespertina, are beautiful little mushrooms that are widespread and common in North America. Many older field guides list the Elfin Saddle as edible, but more recently it has been downgraded to “suspect” or even condemned as outright “poisonous” on account of reports of it causing gastrointestinal distress, coupled with the fact that it has trace amounts of Gyromitrin in it. Gyromitrin is a toxic volatile chemical that is found in Gyromitra gigas and Gyromitra esculenta, and Gyromitrins have been responsible for mushroom-related deaths in the past. Elfin Saddle is poisonous if consumed raw, and those who do choose to eat it discard the tough, rubbery stem.

Elfin Saddle Mushroom Edibility Notes

When you combine the potential risks of upset stomach and exposure to trace quantities of Gyromitrin, the prospect of eating the Elfin Saddle mushroom becomes significantly less appealing. Combined with its overall poor culinary performance (it’s rather bland and you are advised to cook the ever-loving hell out of them to remove the Gyromitrin), the Elfin Saddle is at its best when used as a subject of mushroom photography, in my estimation.

I have eaten the caps of Elfin Saddle mushrooms in the past, and on the whole I was unimpressed and do not plan to try it again. Its rubbery but frail cap sort of fell apart and shriveled into soft, unappealing little curls of weird gunk during cooking. I did not experience any GI distress, but I was very cautious to only eat a very small amount of it, so I could not possibly weigh in on the overall safety and advisability of eating Elfin Saddles based on personal experience.

Elfin Saddle Mushroom Features and Habitat

Helvella lacunosa, Helvella dryophila, and Helvella vespertina  are striking little mushrooms with a lot of character when observed up close. From my towering height of 5’2″, they don’t look like much more than little withered black thingies, but once you get up close and personal with the Elfin Saddle, it becomes almost immediately evident that they are far from boring.
The flesh of Elfin Saddles is rubbery, much like a cup fungus or morel mushroom. Helvella lacunosa, Helvella dryophila and Helvella vespertina are ascomycete fungi, which means that they have microscopic flask-shaped structures on the fertile cap surface that produce spores. Also, as ascomyces they lack gills and have one of the traits many ascomycetes share: they are sort of rubbery and wiggly instead of soft and fleshy.
Elfin Saddle mushrooms fruit in the winter and spring on the west coast, and pop up in the summer and fall in the eastern United States. They are often associated with conifers: I have found Helvella lacunosa (or much more likely, Helvella vespertina) growing close by stands of ponderosa pine, douglas fir, and loblolly pine in the past and most descriptions of Elfin Saddles note their association with coniferous trees of one sort or another. Helvella dryophila is an oak-associated black Elfin Saddle that grows on the west coast. As of the date of this writing, the east coast Elfin Saddle remains a bit of a genetic mystery, although for the purpose of DNA sequencing, one expert suggested to me that the collection by Illinois Patrick Leacock is probably representative of the east coast species of Helvellas that closely resemble Helvella dryophila and Helvella vespertina.
The Elfin Saddle sports a folded, bubbly, or lumpy cap that looks much like Gyromitra. Unlike Gyromitra, however, the Elfin Saddle’s cap is a matte black color that looks a lot like very dark velvet or felt, although at times the cap has hints of grey. It frequently acquires a Hypomyces mold infection that appears as a white powdery layer on top of the black flesh of the cap. The shape of the Elfin Saddle’s cap varies greatly, from flowery two-pointed growths that look like saddles (hence the common name) to bulbous and irregular monstrosities that look more scatological than anything else.
The thing that appeals to me most about the Elfin Saddle is the stem; it is usually streaked and fluted and looks like an ornate grey-white carving in soapstone or a similar medium. It puts me in the mind of hand-dipped candles that have been sculpted to show off different rills and rivulets of melted wax. Also, the stem of Elfin Saddles remind me of old, gnarled trees in many cases, and in my opinion they’re quite lovely to look at.

The Elfin Saddle is My Power Fungus

It may seem silly, but I consider the Elfin Saddle mushroom to be my fungal equivalent of a power animal. It started this way.
One of my finest mushroom hunting memories is indelibly linked to this mushroom. I was in the Sierra Nevada in search of spring morels with a mentor and friend of mine named David Campbell, a mushroom hunter who once found a morel patch that he aptly named 4Bags. We were hiking through a particularly pretty bit of the El Dorado National Forest and having no luck whatsoever with the morels, or any mushrooms at all for that matter.
Disgruntled and a little hot under the collar, we decided to cover as much ground as we could, which meant splitting up. Being the responsible wild mushroom hunters that we are, we had walkee-talkees and decided to check in every 10 minutes and spend the next hour walking about scouting for good morel habitat.
I dove into a dirt-bike blasted bit of territory, using the deep paths torn up by the ATVers to make as much headway as possible, and Dave moved up a distant hillside. 10 minutes into my search, I radioed in.
“Hey Dave, just checking in. Still no mushrooms…hey, wait a second!” As I was talking, a saw a little patch of black Helvellas off to my right . Delighted to find any mushrooms at all, I crowed, “Scratch that, we’ve got Elfin Saddles.”
“Oh good. Well keep looking, I’ll call you in 10.”
“Roger that.”
“You don’t have to use silly police radio-lingo, you know.”
“10-4, Canine Alpha. Helvella over and out.”
“Whiskey Tango Foxtrot. Stop screwing around and find us some morels, Helvella!”
I continued my quest, after bending to collect the prettiest of the Elfin Saddle mushrooms, just so I’d have something to bring home with me. Exactly 10 minutes passed, and I found myself staring at another clump of lumpy black Helvellas with a little smile on my face.
“Helvella, do you copy? There aren’t any morels up here on this hillside, I’m going to descend and run lateral to you for a bit.”
“Yup, got it Canine Alpha. Guess what I’m looking at right now.”
“Unless it’s morels, I don’t really care. But I bet you have more Helvellas, don’t you, Helvella?”
“Sure do.”
“Creepy. Talk to you in a few.”
For the next 40 minutes, this pattern repeated itself without fail. No mushrooms, no mushrooms, and even more no mushrooms, right until it was time to radio in…and then bam. Helvella patches.
I know it’s a little silly, but I really loved how this experience made me feel; it was like the Elfin Saddle mushrooms were playing with me a little bit. I often feel like mushrooms use me for their amusement, and this experience was one of those moments where I felt like I was the butt of a playful fungal joke.
Also, I earned the nickname Helvella that day.
We never did find any morels.