Ecological Restoration Specialists

Author Archive | Ben Alexander

Water Parsley – Oenanthe sarmentosa

Water parsley is a Pacific northwest native plant that grows on stream banks and in wet, shady areas

Oenanthe sarmentosa – Water parsely


Oenanthe sarmentosa

Family: Apiaceae

Water parsley occurs from Alaska to California and prefers wet, low-elevation habitats with full sun. It grows in saturated soil and can often be found in standing water or along streambanks. This preference, combined with the dense biomass this species creates aboveground, renders it useful in the context of wetland restoration as it slows water flow to allow the settling of sediment.

This perennial herb sports a characteristic carrot-family inflorescence, a flat-topped umbel made up of 5-20 tiny white flowers. These bloom from May to July, and produce barrel-shaped seeds. This species has soft, weak stems, which curl at the tips. If a stem touches the ground, it can send out runners from the nodes.

Although cuttings of rooted nodes can be transplanted, this plant propagates best by seed. As with many other seeds, water parsley seeds are dormant until they endure certain winter conditions. When propagating water parsley, these conditions are simulated to trigger germination through a process called stratification. Water parsley does best with a 24 hour soak, followed by 21-30 days of cold stratification. Water parsley seeds are linear and underdeveloped, meaning they exhibit endogenous, morphological dormancy. As a result, they must be allowed to finish development before germination can occur.

Although this species can seem to resemble poison hemlock (Conium maculatum), there are several ways to distinguish them. Poison hemlock is much more robust and thick-stemmed with thicker and more deeply divided leaves. The stems often sport purple blotches. Poison hemlock can grow over eight feet tall, while the maximum height of water parsley is roughly 4.5 feet. The leaves of water parsley are less dramatically toothed but more feathery and thin. Although water parsley does not cause the same symptoms as poison oak, it is still a toxic plant, like many other species in the carrot family, and should not be consumed.

Propagation Protocol

Seed description: Seeds have a strong, acrid smell, and are often slimy when removed from inflorescences. Seeds are brown when mature, and when split open, show a white endosperm.

Preparation: Keep seeds moist and store in a refrigerator. Before sowing, soak seeds for 24 hours, and cold-stratify for 21-30 days.

Sowing: Sow seeds into tubes filled with standard potting mix, and lightly cover them once sown.

Germination: Germination should occur 30 days after sowing, at a success rate of around 50%. Seedlings should be established in tubes after two months.


“Oenanthe Sarmentosa, Pacific Water Parsley.” Washington Native Plant Society: Starflower Image Herbarium. Web. 06 Oct. 2016.

“Propogation Protocol, Oenanthe (Sarmentosa).” Native Plant Network Propogation Protocol Database. Web. 6 Oct. 2016.

“Oenanthe Sarmentosa | Pacific Water Parsley | Wildflowers of the Pacific Northwest.” Web. 06 Oct. 2016.

“Oenanthe Sarmentosa Water Dropwort,Water Parsely PFAF Plant Database.” Web. 06 Oct. 2016.

We are thrilled to once again feature the fabulous artwork of SNP employee Jasmine Doughty, who left the Children’s Hands-On Museum to come back to the nursery.

SNP live stakes outperform others

According to a new study on willow live stake planting by King County, SNP’s wild harvested live stakes outperformed smaller, nursery-grown cuttings and had an astounding 99%  survival rate and 90% cover after 3-years, with absolutely no site preparation or maintenance. You can see the study summary here – in the study, the largest sized stakes were provided by SNP. Even better, we reduced the price on these stakes by 25% since this study was conducted, making them much more cost-effective.

Cornus unalaschkensis – Bunchberry


Plant of the Month

Cornus unalaschkensis – Bunchberry

Bunchberry is the smallest member of the dogwood family. A perennial trailing groundcover with 4 to 6 whorled leaves, bunchberry spreads rhizomatously along the forest floor. It prefers to grow in shade on a thick layer of woody duff in the moist forests or bogs of the western mountains. With 4 luminous white petal-like bracts surrounding a cluster of small flowers in the center, bunchberry blossoms in late spring and summer. In summer and fall, bunchberry develops a tight cluster of red berries borne in an upright spray an inch above the foliage. Songbirds enjoy these edible berries, and various Native American groups harvested them as a food source.

The narrowly ovate, pointed leaves of bunchberry feature prominent veins that curve and meet at the tip. In the winter, some of the semi-evergreen leaves turn red, adding color to the winter months. The plants themselves grow from 4 to 8 inches tall.

Bunchberry blossoms are the fastest-opening flowers in the world, producing a small explosion of pollen. The blossoms open in less than 0.4 milliseconds–less than the time it takes a bullet to travel the length of a rifle barrel.  The pollen’s initial acceleration is more than 2400 times the acceleration of gravity, producing 800 times greater force than astronauts experience during lift-off. This explosion launches the pollen 2.5 centimeters into the air, ten times the height of the flower! To watch a super-high speed video of a bunchberry flower opening, click here.

Thanks to our employee, the talented Sachiko Goode for providing this month’s illustration.

SNP no longer accepting used pots

For years we’ve accepted used pots from the community, and washed and reused them. Sadly, we must now discontinue this service, for two reasons. First, we have grown increasingly concerned about the role of nurseries in spreading potentially disastrous plant pathogens. For example, sudden oak death was introduced into the Pacific Northwest by a nursery shipping infected plants. We have no reliable way to thoroughly sterilize our pots, and we don’t want to be responsible for spreading disease into natural areas. Second, most pots are now manufactured so cheaply that they break apart after one use. In recent years we have landfilled over 70% of the pots people bring us because they are broken and non longer usable. It is with some regret that we make this decision. Sometimes, the path toward responsible ecosystem stewardship is more complicated than we would like, and we think this is the most environmentally responsible choice.