White Snakeroot

White Snakeroot (Ageratina altissima) is in the Sunflowers, Daisies, Asters, and Allies family (Asteraceae). Across the U.S., iNaturalist users have logged 10,085 research-grade flowering observations of it in our sample, peaking in September.

Nationally it blooms mainly from August to October, but timing varies a lot by state and elevation — see the table below.

When to photograph White Snakeroot: observations by month (U.S.)

About White Snakeroot

Ageratina altissima, also known as white snakeroot, richweed, white sanicle, or tall boneset, is a poisonous perennial herb in the family Asteraceae, native to eastern and central North America. An older binomial name for this species is Eupatorium rugosum, but the genus Eupatorium has undergone taxonomic revision by botanists, and a number of the species that were once included in it have been moved to other genera.From Wikipedia via iNaturalist — article, CC BY-SA.

White Snakeroot by state

Main season = months with at least 30% of the state's peak-month count.

Related wildflowers (Sunflowers, Daisies, Asters, and Allies)

black-eyed SusanRudbeckia hirta

Common YarrowAchillea millefolium

ChicoryCichorium intybus

Lawn daisyBellis perennis

Philadelphia fleabaneErigeron philadelphicus

Pearly EverlastingAnaphalis margaritacea

Blue MistflowerConoclinium coelestinum

brown-eyed SusanRudbeckia triloba

Photography tips

• Photograph flowers on calm, overcast mornings to avoid wind blur and harsh shadows.
• Get low: a shallow depth of field (f/2.8–f/5.6) isolates a bloom against soft color.
• Stay on trails — trampling meadows kills plants and ruins next year's display.
• Try a kaleidoscope abstract of a single bloom with our online kaleidoscope tool.

FAQ