''Arceuthobium americanum'' is a species of

dwarf mistletoe The genus ''Arceuthobium'', commonly called dwarf mistletoes, is a genus of 26 species of parasitic plants that parasitize members of Pinaceae and Cupressaceae in North America, Central America, Asia, Europe, and Africa. Of the 42 species tha ...

known as American dwarf mistletoe and lodgepole-pine dwarf mistletoe. It is a common plant of western North America where it lives in high elevation pine forests. It is a

parasitic plant A parasitic plant is a plant that derives some or all of its nutritional requirements from another living plant. They make up about 1% of angiosperms and are found in almost every biome. All parasitic plants develop a specialized organ called the ...

which lives upon the

Lodgepole Pine ''Pinus contorta'', with the common names lodgepole pine and shore pine, and also known as twisted pine, and contorta pine, is a common tree in western North America. It is common near the ocean shore and in dry montane forests to the subalpine, ...

, particularly the subspecies ''Pinus contortus'' ssp. ''murrayana'', the Tamarack Pine. This pine subspecies is most common in the

Cascade Range The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, ...

and

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...

. The American dwarf mistletoe is a yellow-green coral-shaped structure above the surface of the tree's bark, while most of the parasite is beneath the bark. The seeds mature in late summer and disperse to nearby trees. This species has been found to explosively-disperse its seeds through

thermogenesis Thermogenesis is the process of heat production in organisms. It occurs in all warm-blooded animals, and also in a few species of thermogenic plants such as the Eastern skunk cabbage, the Voodoo lily (''Sauromatum venosum''), and the giant wate ...

.
Rolena A.J. deBruyn, Mark Paetkau, Kelly A. Ross, David V. Godfrey &

Cynthia Ross Friedman Cynthia "Cindy" Ross Friedman (1970 or 1971 – 24 December 2018) was a professor in biological sciences at Thompson Rivers University in Kamloops, British Columbia, Canada. She was inducted into the inaugural cohort of the Royal Society of Cana ...

. Thermogenesis-triggered seed dispersal in dwarf mistletoe. The parasitic plant is dioecious, meaning that it has separate male and female parts. Studies of pine needles from infected trees have shown decreased starch content in the needles of infected trees. Furthermore, differences have been found in the positioning of the vascular bundles between female infected pine trees and male infected pine trees.http://rparticle.web-p.cisti.nrc.ca/rparticle/AbstractTemplateServlet?calyLang=eng&journal=cjb&volume=86&year=0&issue=5&msno=b08-019

References

Jepson Manual TreatmentPhoto galleryArceuthobium americanum infection
americanum Plants described in 1850 {{Santalales-stub