A biennial, cow parsnip (Heracleum maximum) is a low-growing rosette with a large, fleshy taproot the first year. In the second year 2 to 8 foot, hairy, grooved flower stalks form.
The inflorescence at the end of the flower stalk is a flat-topped umbel (flowering cluster where the flower stalks radiate from the same point like an umbrella). Individual cow parsnip flowers are white or creme colored and have five petals. The huge leaves are deeply divided and hairy. As the leaves grow older they may become glabrous (without hairs). Cow parsnip seeds have distinct ridges and are flat on one side and rounded on the other. When mature the plant has a strong, pungent odor.
Cow parsnip grows along stream banks, moist slopes and wet clearings throughout most of the Continental United States, except the Gulf Coast. Although cow parsnip is a native plant, it is considered a noxious weed when it crowds out other vegetation.
Even though the leaves and outer skin have a strong odor, Native Americans ate the peeled young stalks and leaf stems either raw or boiled. Once peeled the stalks are sweet and mild. For this reason cow parsnip is also colloquially called Indian celery. A poultice of cow parsnip was used for bruises and sores. A yellow dye can be made from the roots.
Because the outer skin of cow parsnip stems contain furanocoumarins, which can cause skin damage, care must be taken when eating this plant.
This member of the parsley family is also referred to as Heracleum lanatum and Heracleum sphondylium in the literature.
This cow parsnip was growing along Cedar Creek near Cedar Pass (Modoc County CA).