Yosemite Bog Orchid: The Rare (and Smelly) Orchid of Yosemite National Park

A Yosemite bog orchid in flower, observed in Mariposa County, California, on August 6, 2024. Photo: Christopher Foott, CC0 (public domain dedication), via iNaturalist; cropped, with lettering added by Brian Russ Guides.

Most famous wildflowers earn their fame by being showy. The Yosemite bog orchid went the other way. It's a skinny green spike of tiny flowers, it hides in meadows full of grass and look-alike orchids, and by some accounts it smells like a horse corral. It also grows almost nowhere on Earth except a small area in and around Yosemite, which makes it one of the park's most interesting plants.

Botanists only recognized it as its own species in 2007, so if you've never heard of it, you're in good company.

Why This Orchid Is Special

The plant wasn't new in 2007; the name was. A collector named George Henry Grinnell first gathered specimens back in 1923. Botanists found the site again in 1993, and two U.S. Geological Survey botanists, Peggy Moore and Alison Colwell, relocated it starting in 2003. Working with Charles Sheviak of the New York State Museum, they described it as a new species, Platanthera yosemitensis, in the botanical journal Madroño (NPS, 2007 news release).

When the park announced the discovery, it called this the only orchid known to be endemic to the Sierra Nevada, and said it was known from nine sites in Yosemite. It grows on the granite upland south of Yosemite Valley, between the main Merced River and its South Fork. That area stayed largely free of ice during the most recent glaciations, and it's home to at least seven other plants found only in the central and southern Sierra, including the Yosemite onion and Bolander's clover (NPS).

The California Native Plant Society ranks it 1B.2, its category for plants that are rare, threatened, or endangered in California and elsewhere, and fairly threatened within the state (CNPS Rare Plant Inventory).

A flowering spike above a wet meadow, observed in Mariposa County, California, on July 2, 2024. Photo: Reid Hardin, CC BY 4.0, via iNaturalist.

How to Recognize It

Honestly, you probably won't be able to tell it apart on sight, and that's fine. The park describes it as an inconspicuous, wand-like plant with tiny flowers that's easy to miss in crowded meadows, and it shares those meadows with other bog orchids. Botanists separate it from its relatives using several technical features (NPS).

What you can see is the general look: a single slender stem standing up out of the grass, with small pale yellow-green flowers spaced up the top of it, as in the photos here.

The giveaway is your nose. The flowers have a strong musky scent that people have compared to a horse corral, strong cheese, feet, and sweaty clothing. The scientists who described it suggested the smell may draw in mosquitoes or flies as pollinators (NPS). It's a reasonable trade: you don't need to be pretty if the mosquitoes like you.

A closer look at the small yellow-green flowers, observed in Mariposa County, California, on July 28, 2021. Photo: My-Lan Le, CC BY 4.0, via iNaturalist.

Where and When It Blooms

It grows in meadows and seeps on granite, mostly between about 6,900 and 7,500 feet, and it blooms in July and August (CNPS). The park doesn't publish the exact sites, and I won't either. Rare-plant records on iNaturalist hide the locations too, which is why the photo captions here say only "Mariposa County."

If you're reading this in the fall or winter, the show is over for the year; plan on July or August instead. Even if you never knowingly see this orchid, a summer walk past a wet meadow puts you in the kind of place it lives.

Pale flowers along the stem, observed in Mariposa County, California, on September 1, 2023. Photo: Trevor Van Loon, CC BY 4.0, via iNaturalist.

Look, Don't Trample

This is the part that matters most. Yosemite's resource managers have said several populations are very small, the habitat is sensitive, and the roots are delicate (NPS). CNPS lists foot traffic and trampling among the threats (CNPS).

• Stay on the trail through wet meadows, even when it's muddy. Stepping around a puddle widens the damage.
• Leave plants as you find them. Don't pick, dig, or move anything.
• Keep locations to yourself. If you think you've photographed one, share the picture but not the spot.

A Yosemite bog orchid in its meadow habitat, observed in Mariposa County, California, on July 2, 2024. Photo: Reid Hardin, CC BY 4.0, via iNaturalist.

Easier Wildflowers to Find in Yosemite

If you'd like flowers that are a little more cooperative, the park's own wildflower guide is a good start. It points to marsh marigold in wet spots along Glacier Point Road, Gray's lupine around Wawona, harlequin lupine near Hetch Hetchy, and Sierra butterweed in Tuolumne Meadows (NPS, Common Wildflowers).

Planning a trip around the meadows? My guide to Yosemite National Park has nine one- to three-day itineraries at different effort levels, plus the park's history, highlights, and wildlife.

Before you go: see Yosemite National Park alerts and current conditions, checked daily, for current closures and what they mean for your trip.

This is an independent guide. It is not affiliated with or endorsed by the National Park Service. Conditions change; check the park's current alerts before you go.