Conserving Mount Lassen Paintbrush at Swain Meadow

This month, staff from Sierra Institute, the Lassen National Forest, and the Institute of Applied Ecology gathered at Swain Meadow in the Southern Cascades to outplant Castilleja lassenensis —Mount Lassen paintbrush — a rare and endemic species of Northern California. The work is part of a multi-year effort to support a population that is under compounding pressure from hydrologic uncertainty and the effects of the 2021 Dixie Fire — to ensure that Mount Lassen paintbrush can continue to thrive in a meadow that is itself in the process of being restored.

Categories: Community Based Natural Resource ManagementPublished On: June 15, 2026By Jade Elhardt

A Delicate Species

Mount Lassen paintbrush is a local endemic with a California Rare Plant Rank of 1B.3, meaning it is rare throughout its entire range — not just locally. There are only a few dozen known populations, almost entirely within Lassen Volcanic National Park and the adjacent Lassen National Forest. It grows in high-elevation montane meadows between roughly 5,000 and 8,000 feet, and it occupies a precise hydrologic niche: the narrow band between saturated sedge and wetland communities and drier upland vegetation, where conditions are neither too wet nor too dry.

Like all paintbrushes, it is hemiparasitic — it taps into the root systems of neighboring plants for a portion of its water and nutrients. That underground dependency on its surrounding plant community means it is highly sensitive to disturbance. Lose the community, or disrupt the hydrology that supports these intricate relationships, and the paintbrush loses its footing.

Swain Meadow, just north of the town of Westwood, CA, hosts the largest known population of the species. Lassen National Forest botanist Kirsten Bovee and her colleagues had been monitoring it since 2020 — tracking stem counts, plant community composition, and hydrologic niches across six permanent 100-meter transects — when the Dixie Fire burned through the meadow in July 2021 at a variety of intensities.

The post-fire data was stark: stem counts dropped 38% across the study site. The frequency of occurrence fell from 67% to 25% within two years. Most significantly, even plots that experienced only light or moderate burn severity saw a complete loss of pre-fire paintbrush density by year one, with no recovery by year two. The perennial rootstocks of Mount Lassen paintbrush proved sensitive to fire in a way that many other perennial forbs in the meadow were not. Recovery, if it comes at all, will take far longer than two years — and for a population this isolated, passive recovery alone didn’t seem sufficient to keep this isolated population intact.

Restoration, and the Uncertainty That Comes With It

The Dixie fire was one pressure on this sensitive species. The meadow’s hydrological function was another issue entirely. Swain Meadow has been degraded over decades through channelization and draining, reducing its capacity to hold and distribute water across the floodplain. In 2024, Sierra Institute joined Lassen National Forest and Point Blue Conservation Science to implement the Robbers Creek Watershed Restoration Project, which consisted of extensive channel and floodplain work that included riffle augmentation, installation of beaver dam analogs, road contouring, and filling in drainage ditches, all with the goal of slowly re-wetting the meadow and restoring it to its perceived historical state.

As floodplain dynamics shift — water redistributing, elevation gradients subtly changing — so too may the location of suitable habitat for a species like Mount Lassen paintbrush. For these reasons, Sierra Institute and partners made a deliberate decision to proactively augment the paintbrush population rather than wait to see where the hydrology settled and how those changes in turn would affect the Mount Lassen paintbrush populations.

A Tricky Propagation Problem

Propagating paintbrush species from seed is notoriously difficult — Mount Lassen paintbrush’s hemiparasitic biology makes germination finicky and nursery production, frankly, challenging. Sierra Institute turned to the Institute of Applied Ecology (IAE) in Corvallis, Oregon, whose Plant Materials staff, Kate Wellons, had deep experience with a related species: Castilleja levisecta, golden paintbrush, a former federally endangered species that IAE helped bring back from the brink through reintroduction work across Oregon’s Willamette Valley.

Working from seed collected locally at Swain by Sierra Institute staff, the Institute for Applied Ecology developed a successful propagation protocol for Mount Lassen paintbrush after a bit of trial and error— no small feat for a species with no documented grow-out history. Five hundred plugs were produced for a pilot planting in October 2024. Then, approximately 500 more were planted in the fall of 2025. This third and final planting in May of 2026 included more than 600 plugs.

In October 2024, planting plugs were installed along five transects spanning a range of environmental gradients across the restored meadow to begin mapping where Mount Lassen paintbrush can successfully establish under new floodplain conditions. Survival results from the 2024 transects helped us to identify 25 areas with the conditions we believe Mount Lassen paintbrush seedlings can successfully establish and thrive into the future. Last week’s planting continues that work, adding plugs and data points to an adaptive monitoring framework that will guide future planting decisions as survival data accumulates.

Planting in the Cold Rain

The environmental conditions at Swain on this morning in late May were optimal for the transplanting at hand. When teams arrived, they were met with forty-degree temperatures and persistent rain—a truly silver lining that kept the usual droves of the local mosquitoes away for the day. Although conditions may not have seemed ideal to some, the abundant moisture and rain were ideal for the establishment of the newly propagated plugs to survive. The landscape was vibrant with spring phenology; Camassia quamash and Trifolium longipes were in full bloom, alongside the diverse, small-flowered botanical associations characteristic of this high-elevation wetland-upland ecotone.

Kate Wellons oversaw the planting process for the Mount Lassen paintbrush, requiring dibble holes to be narrower than the plugs to ensure root contact with undisturbed soil. Plugs were set level with or slightly above the surface to eliminate air pockets. While the nursery medium tends to dry and contract away from roots, the day’s steady rain provided the critical moisture needed for what will hopefully be a successful establishment.

The planting teams wandered across the established transects, installing the nursery stock one by one with excitement and awe at this beautiful and truly unique species. Guided by pin flags, the young paintbrush plants already flushing with pink were given a permanent home in the native sedge mat of the meadow.

Why This Work Matters

Montane meadows are among the most ecologically productive and climatically significant systems in the Sierra Nevada and Southern Cascades. They enhance groundwater recharge ability, store carbon, support exceptional biodiversity, and function as fire refugia in an increasingly fire-prone landscape. Meadow restoration is one of the many important facets of Sierra Institute’s work. The Swain Meadow effort is a clear example of what restoration looks like in practice: years of monitoring by botanists, propagation breakthroughs by native nursery and horticulture specialists, and a planting and monitoring design that will build knowledge across multiple seasons and years. Many rare species, such as Mount Lassen paintbrush, do not have the luxury of a large, widespread range. Each colony is significant, and a core component of our conservation objective involves ensuring that these rare plants can persist and flourish within their native landscapes.

Sierra Institute for Community and Environment partners with rural communities, tribes, and federal land managers across the northern Sierra Nevada and Southern Cascades to advance forest health, watershed restoration, and community resilience.

We are grateful to Kirsten Bovee and the Almanor Ranger District & Nikki Buckley of the USDA Forest Service Lassen National Forest for leading the project’s planting design as well as years of careful population monitoring and field leadership on this project, and to Kate Wellons, Andrew Esterson, Paul Reed, and the Institute of Applied Ecology for developing the propagation protocols that made this planting possible. Thank you to Point Blue Conservation Science for their partnership on the Robbers Creek Watershed Restoration Project.