Poison hemlock found along Syracuse’s Onondaga Creekwalk, officials warn

Poison hemlock has been found along the Onondaga Creekwalk, putting a toxic invasive plant on one of Syracuse’s most heavily used public paths. The 4.8-mile paved trail runs mostly parallel to Onondaga Creek and connects the Southside neighborhood, Downtown’s Armory Square and Onondaga Lake, making the discovery a direct safety issue for families, dog walkers, cyclists and other trail users.

The plant, known scientifically as Conium maculatum, is a non-native invasive in the carrot family that prefers moist soils and disturbed sites. It can grow 3 to 8 feet tall and has a thick white taproot that can be mistaken for wild parsnip, which makes identification important for anyone walking the corridor or working near its edges.

The danger is not just that the plant looks out of place. WNY PRISM says ingestion can be fatal for humans and livestock, and symptoms may begin within an hour. Those symptoms can include trembling, ataxia, pupil dilation, a weak and slow heartbeat and coma. On a path used by pedestrians, bicyclists, skaters and pets, that puts poison hemlock in the category of a serious public-safety hazard, not just a nuisance weed.

The safest response is to keep distance from any suspected poison hemlock, especially in moist or disturbed stretches of the trail, and to avoid touching, pulling or cutting it. Families moving through the Creekwalk, including children and anyone with dogs, need to treat the plant as a hazard until it is removed and the area is clearly marked. The city will face pressure to move quickly with warning signs and cleanup because the trail is a shared route for everyday recreation and commuting.

The Creekwalk is already under intense attention from city and state projects. Syracuse held a public meeting on April 20, 2026, about the Creekwalk Phase 3 extension project. A separate May 2026 report said the state plans to raise parts of the trail by as much as 10 feet for an I-81 stormwater line. Severe flooding also closed parts of the Creekwalk in August 2021, a reminder that this corridor has repeatedly been tested by both weather and infrastructure work.

For Syracuse, the poison hemlock discovery adds another urgent maintenance problem on a trail that sits at the center of daily life and major public projects. The faster the city can warn trail users and clear the plant, the safer the corridor will be.