A rare plant’s secret stronghold: Additional botanical surveys at Columbia Stock Ranch uncover more Water Howellia populations
Wading through shin-deep water, a small team of scientists, volunteers, and Columbia Land Trust staff spread out across the wetlands of Columbia Stock Ranch in search of a rare plant.
Located in Columbia County, Oregon, the 900-acre site is home to a diverse mosaic of wetlands, forests, and open prairie habitats. Beneath the tall grasses, sedges, and shallow wetland waters, this group was searching for Water Howellia (Howellia aquatilis), a species so rare it was once thought to be extirpated from Oregon. Hidden among dense vegetation, the delicate aquatic plant is easy to overlook, making its discovery feel something like a treasure hunt.
One year after Water Howellia was first discovered on the property, Columbia Land Trust staff joined biologist Jason Clinch of Three Creeks Consulting and volunteers Rick Shory and Larissa Huson in a series of return visits to continue a botanical inventory funded by the Coalition of Oregon Land Trusts (COLT).
Over three spring days, the team revisited known Water Howellia locations, surveyed areas that had not yet been inventoried, and set out to better understand the rare plant’s distribution and habitat preferences.
These surveys documented Water Howellia growing in several locations beyond where it was initially discovered in 2025. Observations suggest that the population likely includes thousands of individual plants.
“This is exciting because it tells us the population is more widespread than we initially realized,” said Jason.
The discovery of Water Howellia in the first place remains remarkable because the site doesn’t fit the image you might imagine when picturing rare plant habitat. “It’s a surprising location, not what I would consider traditional habitat for the species,” Jason explained.
Before a majority of the site was conserved by Columbia Land Trust in 2012, it was diked and managed as cattle pasture and hay fields. Much of the site lies within the Columbia River floodplain, and today the property includes a rich mosaic of wetlands, forests, prairie habitats, and seasonal grazing areas that support a growing diversity of wildlife and native plants.
Also surprising was the abundance of Water Howellia blooming among dense stands of reed canarygrass, an aggressive non-native species that Land Trust stewardship staff are actively working to control.
Along with the location and abundance of Water Howellia, the survey team recorded associated plant species, water conditions, flowering activity, and seed capsule development to better understand the ecological conditions that support the species here. Numerous flowering plants and developing seed capsules were observed, evidence that the population is reproducing successfully and continuing its life cycle across the site. Data collected will help guide future stewardship decisions at the site and contribute to a broader understanding of one of Oregon’s rarest plants. “The more we know about our properties, the better we can care for them,” said Columbia Land Trust Coast Region Stewardship Manager Austin Tomlinson.
You might have rare plants, but you’re not going to know unless someone goes out and looks for them.”
-Jason Clinch, Three Creeks Consulting
These plant inventories also help fill an important knowledge gap for Columbia County, Oregon, where much of the landscape is privately owned and relatively little botanical survey work has been conducted. Survey data collected through the project is shared with organizations including the Oregon Biodiversity Information Center (ORBIC), Oregon Flora, and other researchers working to better understand plant communities across the state.
As part of this year’s effort, the team collected Water Howellia specimens for preservation at the Oregon State University and Portland State University Herbarium. These samples will help researchers study the species and provide future botanists with valuable records from one of Oregon’s few known current populations.
“They only have a handful of collections, and most of them are 100 years old or more,” said Jason.
This ongoing botanical inventory work was made possible through funding from the Coalition of Oregon Land Trusts with support from longtime conservation advocate Jane Hartline. In a fitting twist, Water Howellia was first documented by botanists on Sauvie Island in 1878—the same island where Jane’s native plant nursery operates today.
For Columbia Land Trust, the discovery of Water Howellia at Columbia Stock Ranch serves as both a conservation success story and reminder that nature still has surprises to offer. Last year’s discovery showed us that this rare species had found a foothold in an unexpected place. This year’s surveys suggest that Water Howellia may be more resilient than anyone realized.
