Solitary, slender, branching stems reach 1–3 feet tall and are tipped with 3–6 umbrella-shaped clusters (umbels) of small, white flowers. Note that each large cluster is composed of 5–15 small clusters (umbellets) with short stalks that radiate from the center like spokes of an umbrella. The name cowbane refers to the toxicity of the plant to animals, especially cattle.

FLOWER: June–September. Compound umbels have 5–15 small umbellets on short rays or spokes, each with 10–20 individual flowers. Flowers have 5 white, notched petals. The umbeletts do not have slender bracklets beneath each cluster.

LEAVES: Basal and alternate on stem. Blade 2 3/4–6 5/8 inches long (7-17 cm), pinnately compound with 5–13 oval to lance-shaped leaflets aligned opposite along the midrib; each leaflet is 3/4–2 3/4 inches long (2–7 cm); margins vary from entire to toothed; blades are largest near the base, upper blades smaller with a sheath around the stem.

HABITAT: Moist sandy, gravelly soils; stream banks, wet meadows, seeps, canyon bottoms, drainages; mixed conifers, aspen-spruce-fir forests.

ELEVATION: 7,600–11,000 feet (one record at 5,220 feet on Jemez River, Sandoval Co.)

RANGE: AZ, CO, NM, UT, WY.

SIMILAR SPECIES: Hemlock Parsley, Conioselinum scopulorum, in much the same range and habitat, has parsley-shaped leaflets, and long, slender bractlets directly beneath each small, umbrella-like flower cluster.

NM COUNTIES: Mountains of NM in mid- to high-elevation, moist habitats: Catron, Cibola, Colfax, Grant, Lincoln, Los Alamos, Mora, Otero, Rio Arriba, San Juan, San Miguel Sandoval, Santa Fe, Sierra, Socorro, Taos.