Artemisia estesii (Asteraceae), a new diploid species of the Artemisia ludoviciana complex in the Pacific Northwest (U.S.A.)

  • Kenton L. Chambers Department of Botany and Plant Pathology, Oregon State University


The new species described here, Artemisia estesii, belongs to the Artemisia ludoviciana Nutt. species’ group in the Pacific Northwest. It was shown by J.R. Estes (1968a, 1969) to be a diploid member of an otherwise polyploid hybrid complex, with most of its related species and subspecies occurring at the tetraploid and hexaploid levels. Artemisia estesii is recognized by its underground and emergent, over-wintering, basal shoots, which are homologs of the elongate, underground rhizomes found in other herbaceous Artemisia species. Its regularly lobed leaf blades, with usually a broad rachis, differ from subspecies of A. ludoviciana in eastern Oregon. It occupies a narrow zone of streambank vegetation along the central Deschutes River and extends eastward along the lower Crooked River. Disjunct populations are known from Wheeler County and Lake County.


Allen, G.A., M.L. Dean, & K.L. Chambers. 1983. Hybridization studies in the Aster occidentalis (Asteraceae) polyploid complex of western North America. Brittonia 35:353–361.
Brounstein, H. 1996. Estes’ Artemisia. Kalmiopsis 6:9–12.
Clausen, J., D.D. Keck, & W.M. Heisey. 1940. Experimental studies on the nature of species. I. Effects of varied environments on Western North American plants. Publication No. 520. Carnegie Institution of Washington, Washington, D.C., U.S.A.
Dean, M.L. & K.L. Chambers. 1983. Chromosome numbers and evolutionary patterns in the Aster occidentalis (Asteraceae) polyploid complex of Western North America. Brittonia 35:189–196.
Estes, J.R. 1968a. Cytotaxonomic studies in the Artemisia ludoviciana polyploid complex of the Pacific Northwest. Ph.D. thesis, Oregon State University, Corvallis, Oregon, U.S.A.
Estes, J.R. 1968b. IOPB chromosome number reports. XV. Taxon 17:101–103.
Estes, J.R. 1969. Evidence for autoploid evolution in the Artemisia ludoviciana complex of the Pacific Northwest. Brittonia 21:29–43.
Hall, H.M. & F.E. Clements. 1923. The phylogenetic method in taxonomy. Publication No. 326. Carnegie Institution of Washington, Washington, D.C., U.S.A.
Keck, D.D. 1946. A revision of the Artemisia vulgaris complex in North America. Proc. Calif. Acad. Sci. 4th Ser., 25:421–468.
Lesica, P. 2012. New combinations for the Montana flora. J. Bot. Res. Inst. Texas 6:25–27.
Ornduff, R. & D.H. French. 1960. Distributional notes on plants of the Warm Springs area, Oregon. Madroño 15:225–256.
Shultz, L.M. 2006. Artemisia. In: Flora of North America Editorial Committee, eds. Flora of North America north of Mexico. Oxford University Press, New York, U.S.A., and Oxford, U.K. 19:503–509.
Taylor, R.L. & R.P. Brockman. 1966. Chromosome numbers of some western Canadian plants. Canad. J. Bot. 44:1093–1103.
Tucker, A.O., M.J. Maciarello, & G.O. Sturtz. 1993. The essential oils of Artemisia ‘Powis Castle’ and its putative parents, A. absinthium and A. arborescens. J. Essent. Oil Res. 5:239–242.
Ward, G.H. 1960. Artemisia. In: R.S. Ferris, ed. Illustrated flora of the Pacific States. Vol. 4. Stanford University Press, Stanford, California, U.S.A. Pp. 403–315.
How to Cite
Chambers, K. L. (2017). Artemisia estesii (Asteraceae), a new diploid species of the Artemisia ludoviciana complex in the Pacific Northwest (U.S.A.). Journal of the Botanical Research Institute of Texas, 11(1), 1-9.

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