Family: Poaceae |
Kelly W. Allred and Mary E. Barkworth Plants annual or perennial; densely to loosely cespitose, sometimes rhizomatous; fragrant. Culms 4–100 cm tall, erect or geniculata, sometimes branched; internodes hollow. Leaves cauline or basally concentrated, glabrous or softly hairy; sheaths open; auricles absent or present; ligules membranous, sometimes shortly ciliate or somewhat erose; blades flat or rolled, glabrous or sparsely hairy. Inflorescences open or contracted panicles, sometimes spikelike. Spikelets pedicellate or sessile, 2.5–10 mm long, laterally compressed, stramineous to brown at maturity, with 3(4) florets, lowest 2 florets usually staminate or sterile, sometimes reduced to dorsally compressed lemmas, subequal to or exceeding the distal floret, distal floret bisexual; rachilla not prolonged beyond the base of the distal floret; disarticulation above the glumes, the florets falling together. Glumes unequal or subequal, equaling or exceeding the florets, lanceolate to ovate, glabrous or pilose, keeled; calluses blunt, glabrous or hairy; lowest 2 florets: lemmas strongly compressed, 3-veined, strigosa, hairs brown, apices bilobed, unawned or dorsally awned; distal florets: lemmas somewhat indurate, glabrous or with hairs, shiny, inconspicuously 3–7-veined, unawned; paleas 1-veined, enclosed by the lemmas; lodicules 2 or absent; anthers 2 or 3. Caryopses shorter than the lemma, concealed at maturity, tightly enclosed in the floret; hila less than 1/3 the length of the caryopses, oval. x = 5. Name from Greek anthos, ‘flower’, and Xanthos, ‘yellow’, alluding to the golden color of the panicles of Anthoxanthum sensu stricto. Anthoxanthum is a cool-season genus of about 50 species that grow in cool temperate and arctic regions throughout the world. There are seven species in North America north of Mexico, five of which are native. This treatment follows the recommendation of Schouten and Veldkamp (1985) in merging Anthoxanthum and Hierochloë into a single genus which, in accordance with the International Code of Botanical Nomenclature, has to be called Anthoxanthum. The two genera are quite distinct in North America but, according to Schouten and Veldkamp, intergrade in Asia. The recommendation was endorsed by Zhenlan Wu and Sylvia M. Phillips (2006) in the Flora of China but it is not universally accepted. Phalaris resembles Anthoxanthum sensu lato in its spikelet structure, differing in the greater reduction of its lower florets and in not being fragrant when crushed. Anatomical studies (Pizzolato 1984) also support the close relationship of Anthoxanthum and Phalaris. Pizzolato also stated that, although the bisexual florets of Hierochloë are described as terminal, a microscopic fourth floret is developed distal to the third (bisexual) floret. The fragrance emitted when fresh plants are crushed or burned is from coumarin. In addition to smelling pleasant, coumarin has anti-coagulant properties. It is the active ingredient in Coumadin, a prescription drug used to prevent blood clots in some patients after surgery. A disadvantage of coumarin is that it is metaboloized by species of the fungal genus Aspergillus to dicoumarol. This induces vitamin K deficiency and a susceptibility to hemorrhaging in wounded animals. Because of this, using moldy hay containing Anthoxanthum as feed is dangerous. Wherever they grow, the species that used to be treated as Hierochloë (species 3– 7 in this treatment) have been used by native peoples. Native Americans used them for incense, baskets, and decorations, in addition, they steeped them in water for a hair-, skin- and eyewash and also used them for a cold medicine, analgesic, and insecticide. Early Europeans spread the species in churches at festivals. They can also be used to make ale (Stika 2003). November 2010: We accidentally failed to post the treatment of Anthoxanthum earlier, a point that was brought to my attention on November 26, 2010. Unfortunately, the original file is not permitting changes to be made so I am now retyping it. I am giving priority to the parts that will be of greatest interest to the person who inquired about its availability. The remaining species descriptions will be made available before the end of 2010. I have made some revisions. All are minor to trivial (addition of one reference; changes in phrasing). M. Barkworth SELECTED REFERENCES. Aiken, S.G., L.L. Consaul, and M.J. Dallwitz. 1995 on. Grasses of the Canadian Arctic Archipelago: Descriptions, illustrations, identification, and information retrieval. http://www.mun.ca/biology/delta/arcticf/aaintro/caaintro.htm; Belk, E. 1939. Studies in the anatomy and morphology of the spikelet and flower of the Gramineae. Ph.D. dissertation, Cornelll University, Ithaca, New York, U.S.A. 183 pp.; Hedberg, I. 1990. Morphological, cytotaxonomic and evolutionary studies in Anthoxanthum odoratum L. sens. lat.–A critical review. Sommerfeltia 11:97–107; Hitchcock, A.S. 1951. Manual of the Grasses of the United States, ed. 2, rev. A. Chase. U.S.D.A. Miscellaneous Publication No. 200. U.S. Government Printing Office, Washington, D.C., U.S.A. 1051 pp.; Norstog, K.J. 1960. Some observations on the spikelet of Hierochloë odorata. Bull. Torrey Bot. Club 87:95–98; Pizzolato, T.D. 1984. Vascular system of the fertile floret of Anthoxanthum odoratum L. Bot. Gaz. 145: 358–371. Schouten, Y. and J.F. Veldkamp. 1985. A revision of Anthoxanthum including Hierochloë (Gramineae) in Malaysia and Thailand. Blumea 30:319–351; Stika, J. 2003. Sweetgrass ale. http://www.byo.com/stories/recipeindex/article/recipes/113-spice-herb-a-vegetable-beer/1472-sweetgrass-ale. Weimarck, G. 1971. Variation and taxonomy of Hierochloë (Gramineae) in the Northern Hemisphere. Bot. Not. 124: 129—175. Weimarck, 8. 1987. Hierochloë hirta subsp. praetermissa , subsp. nova (Gramineae, an Asiatic-European taxon extending to N and C Europe in the Northern Hemisphere. Symb. Bot. Upsal. 2: 175–181. Wu, z. and S.M. Phillips. 2006. Anthoxanthum, p. 336–339 in Wu, Z., P.H. Raven and D. Hong (Eds.). Flora of China, vol. 22. Science Press, Beijing, China and Missouri Botanical Garden Press, St. Louis, Missouri, U.S.A. |