The Spring King Bolete, Boletus rex-veris

Quick Editorial Note

Before I dive into this article about spring king boletes (Boletus rex-veris), I wanted to quickly note that the comments on this blog are working again. I had a few technical issues over the past couple weeks, which meant the comments weren’t showing up at the bottom of each post, even though I had approved them. However, they’re fixed, so feel free to leave a comment or share a mushroom story if you’re so inclined! And now back to our regularly scheduled program…

Spring King Boletes – An Overview

One of the greatest gourmet wild mushrooms in the western United States is the spring king bolete, Boletus rex-veris. This deluxe-sized porcini mushroom grows in the Pacific Northwest and south into the mountains of northern California. The spring king bolete is a handsome devil indeed, sporting a reddish-brown cap, and a thick, chunky stem with an interlocking web of markings called reticulation. 

I am on quite a tear about porcini and Boletus mushrooms lately and I must apologize for this. I simply cannot help it; many of my best mushroom hunting memories are from forays where we were after porcini. My success with the spring king bolete is unparalleled when measured up against other porcini-type mushrooms I have sought after. To this day, I have dried spring king boletes in my cabinet, even though I moved to North Carolina a couple years ago and have not visited spring king bolete territory in three seasons.

A mature porcini mushroom, Boletus rex-veris.
A mature porcini mushroom, Boletus rex-veris. Note the reticulation on the top of the stem. This is a signature trait of some boletus mushrooms, including the most delicious ones like Boletus edulis and Butyriboletus regius. Photo by Anna McHugh.

Spring king boletes are edible and choice. They have a nutty and slightly fruity flavor, and when they are young and firm they deliver a delightful crunch that’s sometimes as intense as celery fresh from the crisper. This robust firmness makes spring king boletes my favorite porcini, because I find it to be more difficult to prepare more delicate, squishy relatives like the king bolete (Boletus edulis) and the butter bolete (Butyriboletus regius). 

Spring king boletes are different from the classic porcini mushroom, Boletus edulis, in part because their cap is more vibrantly colored; the traditional king bolete has a buttery-brown cap that sometimes looks much like a hamburger bun. The spring king bolete, by contrast, has a reddish-cinnamon cap and an off-white stem. Both Boletus edulis and Boletus rex-veris have thick, chunky stems that are sometimes just as wide as the mushroom cap itself.

Spring kings, like all Boletus mushrooms, have a layer of fertile tissue underneath the cap that is made up of spongy tubes that produce mushroom spores. When the mushrooms are young, this sponge is brittle and hard and pure white in color, and the holes in the tubes are quite small. The spongy layer under the cap of a young spring king bolete is packed with a multitude of little dimples that sometimes catch drops of dew and make the bottom of the mushroom glimmer. Of course, this is assuming that the spring king bolete makes it out of the duff on the forest floor and is exposed to air during its growth cycle.

In addition to the reddish hue of their caps, spring king boletes very frequently have a dusting of white coloration around the contoured edges of the caps; this is called “bloom,” and it is particularly evident when the mushroom is young (see photo). The stem tends to be larger in the lower and middle section and tapers at the top, sometimes fairly extremely. The spring king bolete has a pleasing, earthy aroma that is faintly sweet. The tubes on the bottom of Boletus rex-veris caps can become quite deep (up to an inch or two), but when they are young, the tube-sponge surface is quite thin and very firm.

Spring king boletes often don’t become exposed and obvious to the eye until they are fully mature, if at all. Instead, hunting for these boletes requires looking for bumps (sometimes called mushrumps by those who are too excited to say “MUSHROOM BUMP!”) in beds of conifer needles covering the forest floor. Naturally, this can lead to some consternation; the first time I hunted spring king boletes I found far more rocks and pine cones under my “mushrumps” than actual mushrooms. However, with a little practice, spring king bolete bumps start to become obvious to a mushroom hunter. Unlike permanent fixtures on the forest floor like rocks, the bumps caused by mushrooms arise quickly, and so they tend to have a slightly different appearance because they are “fresh” bumps.

Porcini mushroom button
A Boletus rex-veris button. Note the “bloom” of white around the cap. Photo gleefully snapped by Anna McHugh.

Boletus rex-veris was, for many years, assumed to be a reddish variant of the true king bolete (Boletus edulis). In 2008, the spring king bolete was granted status as a distinct species. It is a commercially valuable mushroom in the western United States; its propensity for growing in higher elevations and cooler climates than Boletus edulis gives it an edge in the market, in part because it is less likely to be worm-eaten than true king boletes, and they often reach a substantial size before they start to decompose or become too insect-damaged to be valuable.

 Spring King Bolete Habitat and Distribution

Spring king boletes are mycorhizzal, meaning that they are mutualists living in partnership with a tree partner, presumably conifers. They are reasonably common around ponderosa pine, several species of fir, and other evergreen trees. They also really like wet, but not soggy, ground. As a consequence, they often form in areas where there has been a good bit of snow, but not so much accumulation that the spring-time habitat becomes a veritable bog of snow-melt runoff.

Boletus rex-veris grows largely at higher elevations between 4,000 and 8,000 feet above sea level, but it ranges down into the foothills of the Cascade Mountains in Oregon and Washington, where wet and rainy conditions supplant snowy weather. The best place to find them, in my experience, is a few hundred feet below the snow line around 5,000-6,000 feet above sea level, in mountainous forests of ponderosa pine. It does exceedingly well in campgrounds as well, and is easily spotted due to the fact that the pine debris is more shallow in places frequented by campers.

One (almost) sure-fire place to look for spring king boletes is directly behind or next to Forest Service latrines and other structures. Just make sure you don’t startle someone who is having a private moment. A friend of mine once found a lovely patch of spring king boletes right next to the front door of a campground bathroom and let out a shrill mushroom-hunter’s war whoop, which was shortly followed by an angry fisherman storming out of the latrine and demanding an explanation for this needlessly alarming behavior.

Hunting for Spring King Boletes in the California Mountains

Spring king boletes, as the name indicates, are a springtime phenomenon, and usually come out between late May through early to mid-June. One way to tell that the timing is right is temperature; it’s ideal if the soil warms to to the high 50s and low 60s in places where the snow has fully melted. Another tell is the wind; if the breeze is still frigid and cuts through your coat, you’re too early for the spring king bolete; it should be cool but not cold, and the slight hint of a warm, balmy breeze is a good indication of spring king season.

Hunting for spring king boletes in the Sierra Nevada of northeastern California is a lovely enterprise, because they come out when the air warms just enough to melt the snow, leaving the forest floor drenched and ripe for an explosion of mushroom growth. Avoid downright muddy patches, and stick to reasonably wet territory, and cover as much ground as you can; given how large the spring king bolete gets, you do not need to take a snail’s pace to notice and harvest them.

Spring king boletes and morels appear right around the same time in the Sierra Nevada, although the morels tend to make their appearance a wee bit earlier than the porcini. If you’re in good habitat for porcini, you should keep your eyes peeled for morels as well. The trouble with this is that, as mentioned, you can move pretty quickly and still find most of the spring king boletes around you, whereas morels take a more meticulous and deliberate approach. To mitigate this discrepancy, I start out my day by looking for porcini, covering lots of ground and making a mental note of places that seem the most likely for morels. Once I’ve satisfied myself that I’m done with spring king boletes for the day (and when my feet get tired), I return to the spots that looked morel-worthy and reduce my pace and increase my focus, peering carefully under the shrubbery and putting myself in a Waldo-finding mindset.

At the same time of year, a number of other beautiful plants and wildlife are evident in the Sierra Nevada, including the impeccable snow plant, which is a mycotrophic plant that does not produce chlorophyll; instead, it relies on a mycorhizzal relationship with fungal partner that borrows nutrients from another plant in the forest and delivers it to the snow plant. These strikingly beautiful snow plants are also an excellent indicator species for spring king boletes; they favor the same conditions and habitats. However, a quick word of warning: look but do not touch! The snow plant is a protected species and should not be gathered. Furthermore, like the beautiful and rare Indian pipe that grows in the forests of the North Carolina Piedmont region, snow plants will lose their brilliant color once they dry, so it’s best to simply admire them in their natural state.

Snow plant
The mycotropic snow plant relies on a fungus partner to survive; it cannot produce its own food through photosynthesis, but instead depends on a mycorrhizal relationship with mycelium. Photo by Anna McHugh.

 Concluding Thoughts on Spring King Boletes

One of the things I adore about this specific species of porcini is that it is so bountiful; patches of spring king boletes can be made up of many individuals, and it does not take long to collect as many as you could possibly want if you hit a run of them. If you are hunting for spring king boletes in the National Forests of the Sierra Nevada (including the Tahoe National Forest and El Dorado National Forest), it is a good idea to check out what the mushroom hunting rules are. When I lived there, one was allowed to get a free mushroom collecting permit from the ranger’s station, and then you were allowed to harvest mushrooms on a noncommercial basis. Although as time goes on those rules and regulations may change, in general spring king bolete hunting is not frowned upon by Forest Service employees, as long as you’re willing to get the permit and you do not intend to take tons of them.

Another reason I encourage people to try hunting for spring king boletes is that it’s a great break from the occasional anguish and intense, competitive concentration of morel season. Although morels are great and I will be posting a series on morel mushroom season in this coming week or so, I love the spring king bolete because it’s a mellow mushroom to hunt. You get to stride along confidently, and even if you only find a couple of them, you’ll have more than enough gourmet wild mushrooms for a meal or three. Even better if you know where to look; since they are mycorrhizal, you can expect to find spring king boletes close to the same spot you encountered them in previous years, again unlike morels. So if you get sick of striking out on morels in the mountains of Oregon, Washington, and California, give Boletus rex-veris a try; at the very least you’ll get to see more of the forest, and at best you’ll end up with a stash of delicious dried mushrooms that will last for years.


4 thoughts on “The Spring King Bolete, Boletus rex-veris”

  1. Hi Anna, Nice post here – the mycotrophic plants are surely some of the weirdest forest plants going! I remember the first one I ever saw, it was in early summer and I thought it was a mushroom of some kind – I cut it and took it back to ID – took me weeks to finally figure out what it was. The one we see most often around here (SW Oregon) is Allotropa virgata, (candy cane plant) which is an indicator for matsutake.

    1. Thanks! I love the mycotrophic plants…now that I live in North Carolina, I regularly see Indian pipe and it’s one of my all-time favorites. I wish we had candy cane plants (and matsutake!) on the east coast. I surely loved finding matsies in northern California’s mountains and the coast range/Cascades in Oregon.

    1. Hey Tina, I would strongly suggest the Texas mushroom guide, as well as Mushrooms of the Southeastern U.S.; both books have a good selection of species that grow in Louisiana. Also, the mycology subreddit is a good place to look, post pictures for identification, and so forth. Finally, Mushroom Observer is a terrific resource; search for your area and it will pull up species lists, observations of different species in your location, and so forth. At least that’s where I would start. Like the piney woods of eastern Texas, Louisiana is a mushroom-rich part of the country.

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