Razoumofskya pusilla (Peck) Kuntze Arceuthobium pusillum is a perennial, obligate parasitic plant in the sandalwood family.

It is one of the most widespread dwarf mistletoes within its range which covers the eastern United States and Canada, from Saskatchewan to Nova Scotia and New Jersey.

[3][4] She wrote in September 1870 to the Torrey Botanical Club explaining that she had found a parasitic plant that she believed to be a mistletoe.

Eastern dwarf mistletoe parasitizes several genera of conifers including spruces, pines, firs and larches.

The combined effects of dwarf mistletoe distort and suppress the growth of branches and affect the main trunk by causing swellings, knots, or structural weakening.

[9] While A. pusillum does not spread rapidly and therefore cannot be considered a highly invasive species, it can build up gradually within a stand of trees and cause severe damage.