[1] Leptopyrum fumarioides is an annual[2] herbaceous plant growing to 8–30 cm (3–12 in) tall, with 4–9 (rarely as few as 2 or as many as 17) smooth, sparsely branched stems.

Jean-Baptiste Lamarck disagreed with the attribution to Isopyrum and instead classified the plant in 1789 as a hellebore, Helleborus fumarioides.

[1] In 1807, Richard Anthony Salisbury followed Linnaeus in assigning the plant to Isopyrum but renamed the species as I. fumariifolium (meaning "with leaves like fumitory").

[3] The fungi Puccinia actaeae-agropyri and Sphaeropsis isopyri are known parasites of the species, forming pustules and spots on the leaves respectively.

Chemicals in the plant have been found to protect DNA from damage from catechol, probably by acting as potent antioxidants.