Flower:

Convex cluster (umbel) to 5 inches across made up of groups (umbellets) of 10 to 20 flowers each. Flowers are about 1/8 inch across with 5 white petals that are somewhat heart-shaped and may be of unequal size.

At the base of the umbel are 6 to 10 narrow bracts that curve down away from the cluster. Smaller bracts are at the base of each umbellet. Umbels form at ends of branches and upper leaf axils on stiff, 4 to 6 inch stalks.

Leaves and stems:

Leaves are compound with 7 to 17 lance to linear leaflets, 2 to 5 inches long, ¼ to ½ inch wide, sheathing the stem and becoming smaller in the upper plant, typically with tiny, sharp teeth around the edges but occasionally smooth. Submersed basal leaves are double compound with feathery, bi-sected lobes. Stems are stout, typically single with marginal branching in upper plant, Both stems and leaves have smooth surfaces.

Fruit:

Fruits is a somewhat flattened oval capsule about ¼ inch long, obviously ribbed, that splits into 2 seeds.

Notes:

Water Parsnip is common along shallow, marshy streams and drainage ditches or scattered throughout open wet meadows. It often shares its habitat with 2 similar species: Water Hemlock (Circuta maculata), and Bulblet-bearing Water Hemlock (Circuta bulbifera), but the leaves easily distinguish the 3 species. C. maculata has double compound leaves with broad, flat, sharply toothed, stalked leaflets; C. bulbifera also has double compound leaves but the leaflets are narrow and nearly thread-like.