Heracleum lanatum (H. maximum)
cow parsnip
Habit: grows to be a robust, multi stemmed, erect herbaceous perennial. Hollow stems and leaves are densely hairy. The enormous basal leaves are round to kidney shaped, becoming 7-20 in (20-50 cm) wide, sharply serrated and lobed. The fragrant, almost flat-topped inflorescence is a large umbel with 15-30 white flowers. Flower buds appear as conspicuous, large, swollen areas on the stem, sometimes the swellings are as large as an orange. Two seeds are enclosed in a large flat, green, egg-shaped dry fruit with 2 broad wing-like sides. Seed heads have a parsley-like scent and persist into early winter in the umbel formation. Blooms early summer to early autumn.
Ecology: found in riparian zones, moist woods, meadows, thickets and disturbed areas up to elevations of 8500 ft (2600 m), native throughout much of North America.
Growing Conditions: full to partial sun in moist soil, low drought tolerance.
The broad flower heads attract many insects, bees, butterflies and/or birds. In some portions of its range it may be considered weedy or invasive. It is listed as endangered in Kentucky and of special concern in Tennessee. Heracleum lanatum can cause a very itchy rash similar to poison oak in some people. The plant contains a phototoxin, furanocoumarin, and can cause a reaction after coming in contact with the plant, followed by exposure to sunlight. It’s best to plant away from pathways.
Specs
Herbaceous Perennial
3-10 ft (1-3 m)
2-4 ft (.5-1.5 m)
3a-9b