[The Parsley Family in Mt. Adams Country]

American Cow-parsnip, Cow Parsnip

Heracleum maximum

Synonyms: Heracleum douglasii, Heracleum lanatum, Heracleum sphondylium ssp. montanum, Heracleum sphondylium var. lanatum, Pastinaca lanatum

Seeds of American Cow-parsnip, Cow Parsnip: Heracleum maximum (Synonyms: Heracleum douglasii, Heracleum lanatum, Heracleum sphondylium ssp. montanum, Heracleum sphondylium var. lanatum, Pastinaca lanatum)

The photo above shows the fruits of cow parsnip as seen along the Island Springs Trail #66 at Hellroaring Creek.........August 25, 2005.
American Cow-parsnip, Cow Parsnip: Heracleum maximum (Synonyms: Heracleum douglasii, Heracleum lanatum, Heracleum sphondylium ssp. montanum, Heracleum sphondylium var. lanatum, Pastinaca lanatum)The photo at right shows the large leaves and umbels of cow parsnip as seen along the South Fork Spring Creek on the northern slopes of Mt. Adams...........July 12, 2005. Note the large, inflated bases to the leaf petioles and the numerous white, spreading hairs on the stems. The large, attractive lupine is large-leaf lupine (Lupinus polyphyllus ssp. polyphyllus).
Characteristics:

Cow parsnip is a large, fairly attractive perennial wildflower with a single, stout and erect stem from one to three meters high. The lower stems may be lightly haired, but the underside of the leaves and upper stems near the inflorescence are thinly tomentose to woolly-villous. The stems are hollow and heavily veined. The large leaves are once-ternate with broad petiolate leaflets which are palmately veined with coarsely toothed margins. The blades of the leaflets are roughly 10-30 cm long and about as wide, with the central leaflet the largest.

The inflorescence is a compound umbel (See photo below.) with 10-30 unequal rays, each from 5-10 cm long. The flowers are white, with the outer flowers of the outer umbellets having large, deeply obcordate petals. The fruit are broadly elliptic to obovate in shape with a notch at the apex, and range from 8-12 mm long and 7-9 mm wide. Cow Parsnip is a prolific self-seeder.

Habitat:

Cow parsnip is found along streambanks and on moist ground in shady woods.

Range:

Cow parsnip is found from Alaska south to California and Arizona and east to Newfoundland and hence south to Georgia. It is also found in Siberia and the Kurile Islands.

On Mt. Adams this species may be found:

1. Island Springs Trail

2. Meadows along Hellroaring Creek on the southeast side of Little Mt. Adams

3. South Fork Spring Creek on the north side of Mt. Adams

4. Killen Creek on the north side of Mt. Adams.

Umbel of American Cow-parsnip, Cow Parsnip: Heracleum maximum (Synonyms: Heracleum douglasii, Heracleum lanatum, Heracleum sphondylium ssp. montanum, Heracleum sphondylium var. lanatum, Pastinaca lanatum) - Leaves of American Cow-parsnip, Cow Parsnip: Heracleum maximum (Synonyms: Heracleum douglasii, Heracleum lanatum, Heracleum sphondylium ssp. montanum, Heracleum sphondylium var. lanatum, Pastinaca lanatum)

The photo at left shows the umbel of cow parsnip as seen along the Island Springs Trail at the eastern side of Mt. Adams.........July 1, 2005. Note the irregularly sized petals for each flower, with the petals at the outer edge of an umblet being the largest. The image at right shows the leaves of cow parsnip as seen along the irrigation canal adjacent to the Willard Springs Trail, Conboy Lake National Wildlife Area......May 2, 2024.

Umbel of American Cow-parsnip, Cow Parsnip: Heracleum maximum (Synonyms: Heracleum douglasii, Heracleum lanatum, Heracleum sphondylium ssp. montanum, Heracleum sphondylium var. lanatum, Pastinaca lanatum)

A side view of an umbel of cow parsnip as seen along the Island Springs Trail at the eastern side of Mt. Adams.........July 1, 2005.
Paul Slichter