A morphological comparison of Arceuthobium abietinum and A. campylopodum (Viscaceae) and nomenclatural changes for A. abietinum


  • Robert L. Mathiasen School of Forestry, Northern Arizona University
  • Shawn C. Kenaley Department of Environmental Conservation and Horticulture, Finger Lakes Community College




Abies, Arceuthobium, discriminant function analysis, dwarf mistletoes, subspecies


Fir dwarf mistletoe (Arceuthobium abietinum, Viscaceae) parasitizes true firs (Abies spp.) in the Pacific Northwest through California, the Southwest, and into northern Mexico. At present, fir dwarf mistletoe consists of two special forms (formae speciales, f. sp.) and one subspecies that are morphologically similar, but exhibit a high degree of host specificity. However, A. abietinum has been treated as a subspecies of A. campylopodum or conspecific with it in some taxonomic treatments. Therefore, we undertook this study to compare the morphologies of these dwarf mistletoes; collecting morphological data from nearly 100 A. abietinum and 60 A. campylopodum populations collected across most of their geographic ranges and analyzing these data using univariate and multivariate statistical tests. Our results demonstrated that the special forms and subspecies of A. abietinum are morphologically distinct from A. campylopodum, thereby, supporting the continued recognition of A. abietinum as a separate species. Furthermore, our analysis found significant differences for several of the characters we examined between the special forms of A. abietinum. Therefore, we recombined the special forms as subspecies: A. abietinum subsp. abietinum (formerly f. sp. concoloris) and A. abietinum subsp. magnificae (formerly f. sp. magnificae). The previously described A. abietinum subsp. wiensii was morphologically distinct from subsp. abietinum and subsp. magnificae. The distinctiveness of these taxa was supported by their host affinities as well.


Hawksworth, F.G. & D. Wiens. 1972. Biology and classification of dwarf mistletoes (Arceuthobium). Agric. Handb. 401. USDA Forest Service, Washington, D.C., U.S.A.

Hawksworth, F. G. & D. Wiens. 1996. Dwarf mistletoes: Biology, pathology, and systematics. Agric. Handb. 709, USDA Forest Service, Washington, D.C., U.S.A.

Hickman, J.C. (ed.). 1993. The Jepson manual: Higher plants of California. University of California Press, Berkeley, California, U.S.A.

Hunt, R.S. 1993, Abies. In: Flora of North America Committee, eds. Flora of North America. Volume 2. Oxford University Press, New York, New York, U.S.A. Pp. 354?362.

Kuijt, J. 2012. Viscaceae. In: Baldwin, B.G., D. Goldman, D.J. Keil, R. Patterson, T.J. Rosatii, and D.H. Wilken, eds. The Jepson manual: Vascular plants of California. University of California Press, Berkeley, California, U.S.A. Pp. 600–603.

Lanner, R.M. 2010. Abies magnifica var. critchfieldii, a new California red fir variety from the Sierra Nevada. Madroño 57:141?144.

Liu, T. L. 1971. A monograph of the genus Abies. National Taiwan University, Taipei, Taiwan.

Mathiasen, R.L. 2007. A new combination for Hawksworth’s dwarf mistletoe (Viscaceae). Novon 17:217?221.

Mathiasen, R.L. 2008. New combinations for Arceuthobium aureum (Viscaceae) in Mexico and Central America. Novon 18:571?579.

Mathiasen, R.L. 2010. First report of white fir dwarf mistletoe (Arceuthobium abietinum f. sp. concoloris) on Mexican spruce (Picea mexicana) in northern Mexico. Pl. Dis. 94:635.

Mathiasen, R.L. 2011. Morphological comparisons of white fir and red fir dwarf mistletoes in the Sierra Nevada and southern Cascade Mountains. Madroño 58:101?105.

Mathiasen, R.L. 2019. Susceptibility of red fir and white fir to fir dwarf mistletoe (Arceuthobium abietinum) in California. Forest Pathol. doi: 10.1111/efp.12516.

Mathiasen, R.L. & C.M. Daugherty. 2007. Arceuthobium tsugense subsp. amabilae, a new subspecies of hemlock dwarf mistletoe (Viscaceae) from Oregon. Novon 17:222?227.

Mathiasen, R.L. & C.M. Daugherty. 2009. Arceuthobium abietinum subspecies wiensii, a new subspecies of fir dwarf mistletoe (Viscaceae) from northern California and southern Oregon. Madroño 56:118?126.

Mathiasen, R.L. & S.C. Kenaley. 2015a. A morphometric analysis of Arceuthobium campylopodum, A. laricis, and A. tsugense (Viscaceae). Phytologia 97:200?218.

Mathiasen, R.L. & S.C. Kenaley. 2015b. A morphometric analysis of dwarf mistletoes in the Arceuthobium campylopodum-occidentale complex (Viscaceae). Madroño 62:1?20.

Mathiasen, R.L. & S.C. Kenaley. 2017. Arceuthobium tsugense (Viscaceae): Four subspecies with contrasting morphologies and host distributions. J. Bot. Res. Inst. Texas 11:363?390.

Meyers, S.C. 2015. Gymnosperms. In: S.C. Meyers, T. Jaster, K.E. Mitchell, and L.K. Hardison, eds. Flora of Oregon Volume 1: Pteridophytes, Gymnosperms, and Monocots. BRIT Press, Fort Worth, Texas, U.S.A. Pp. 108?126.

Nickrent, D.L. 2012. Justification for subspecies in Arceuthobium campylopodum (Viscaceae). Phytoneuron 51:1?11.

Nickrent, D. L. 2016. Viscaceae Batch—Christmas mistletoe family. In: Flora of North America Editorial Committee, eds. Flora of North America. Volume 12. Oxford University Press, New York, New York, U.S.A. Pp. 422?440.

Oline, D.K. 2008. Geographic variation in chloroplast haplotypes in the California red fir-noble fir species complex and the status of Shasta red fir. Canad. J. Forest Res. 38:2705?2710.

Ott, T. 2014. The geographic and ecological patterns of genetic variation in the Abies grandis-Abies concolor complex. Ph.D. Dissertation, University of Idaho, Moscow, U.S.A.

Parmeter, J.R. & R.F. Scharpf. 1963. Dwarf mistletoe on red fir and white fir in California. J. Forestry 61:371?374.

Quiñonez, S. 2016. Caracterización de los muérdagos enanos que afectan los bosques de coníferas en los estados de Durango y Sinaloa, México. MS Tesis, Universidad Juárez del Estado de Durango.

Quiñonez, S., R.L. Mathiasen, & S. Gonzalez Elizondo. 2013. First report of white fir dwarf mistletoe (Arceuthobium abietinum f. sp. concoloris) on Durango fir (Abies durangensis) from Durango, Mexico. Pl. Dis. 97:431.

Quinn, G.P. & M.J. Keough. 2002. Experimental design and data analysis for biologists. Cambridge University Press, Cambridge, UK. doi:10.1017/CBO9780511806384

Rancher, A. C. 2002. Methods of multivariate analysis. Second edition. John Wiley and Sons, Inc., New York, New York, U.S.A. doi:10.1002/0471271357

Scharpf, R.F. & J.R. Parmeter, Jr. 1967. The biology and pathology of dwarf mistletoe, Arceuthobium campylopodum f. abietinum, parasitizing true firs (Abies spp.) in California. Tech. Bull. 1362, USDA Forest Service, Washington, D.C., U.S.A.

Scott, J.M. & R.L. Mathiasen. 2009. Bristlecone pine dwarf mistletoe: A new subspecies of spruce dwarf mistletoe (Viscaceae) from northern Arizona. J. Bot. Res. Inst. Texas 3:13?22.

Sudworth, G.B. 1908. Forest trees of the Pacific slope. USDA Forest Service, Government Printing Office, Washington, D.C., U.S.A.

Wass, E.F. & R.L. Mathiasen. 2003. A new subspecies of Arceuthobium tsugense (Viscaceae) from British Columbia and Washington. Novon 13:268?276.

Xiang, Q., R. Wei, Y. Zhu, A. Harris, & X. Zhang. 2018. New infrageneric classification of Abies in light of molecular phylogeny and high diversity in western North America. J. Syst. Evol. 56:562?572.



How to Cite

Mathiasen, R. L., & Kenaley, S. C. (2019). A morphological comparison of Arceuthobium abietinum and A. campylopodum (Viscaceae) and nomenclatural changes for A. abietinum. Journal of the Botanical Research Institute of Texas, 13(1), 83–101. https://doi.org/10.17348/jbrit.v13.i1.829