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Hierochloe odorata is a member of the grass family (Poaceae). It is also known by the alternative name Anthoxanthum nitens, as used in the Flora of China and Flora of North America. The common name, sweet grass, refers to the fragrance emitted when fresh plants are crushed or burned to release the vanilla-scented compound coumarin, which it contains. The common name holy grass relates to its use in church festivals by early Europeans.

[KSP]

Kew Species Profiles

General Description

Hierochloe odorata is a member of the grass family (Poaceae). It is also known by the alternative name Anthoxanthum nitens, as used in the Flora of China and Flora of North America. The common name, sweet grass, refers to the fragrance emitted when fresh plants are crushed or burned to release the vanilla-scented compound coumarin, which it contains. The common name holy grass relates to its use in church festivals by early Europeans.

Species Profile
Geography and distribution

Native to Europe, Asia and North America, Hierochloe odorata is also widely naturalised. In North America it grows along the eastern coast from Labrador to New England.

Description

Overview:   Hierochloe odorata is a perennial, hairless or sparsely hairy, tufted plant with slender, creeping underground stems (rhizomes) and grows up to 55 cm tall.

Leaves:  The aromatic leaf blades are 18-30 cm long and 0.04-0.10 cm wide. The edges of the leaf blades are slightly rough.

Flowers:  The flowering parts are held in an open panicle (branched flowering structure), which is 4-11 cm long. The fertile spikelets (structures within which the flowers are held) are borne on hairless stems (pedicels) 2-4 mm long. The spikelets are composed of two sterile florets and one fertile floret.

Fruits:  The fruit is a small, dry, thin-walled fruit with a single seed fused to the ovary wall (this fused product found in most grass species is termed a caryopsis).

Uses

Sweet grass has been used by Native Americans as incense, medicine for colds, analgesic and insecticide and in basketry; they also soaked it in water and used the infusion to wash their hair, skin and eyes.

Strewn on church floors by early Europeans, sweet grass was in some places dedicated to the Virgin Mary. Hierochloe odorata has also been used as an ingredient in strong alcoholic drinks in Eastern Europe. The Swedish botanist Carl Linnaeus reported that it was sold in Sweden to be hung over beds to induce sleep.

The distinctive, sweet scent of H. odorata is due to the presence of the chemical compound coumarin, which is also used to manufacture warfarin, used as a drug in surgery to prevent blood clotting and also as a rat poison.

Known hazards

Mouldy hay containing Hierochloe odorata should not be fed to cattle as Aspergillus species (fungi) turn coumarin into dicoumarol, which induces vitamin K deficiency and makes wounded animals more susceptible to bleeding.

Millennium Seed Bank: Saving seeds

The Millennium Seed Bank Partnership aims to save plant life worldwide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.

There are six collections of Hierochloe odorata held in Kew's Millennium Seed Bank based at Wakehurst in West Sussex.

This species at Kew

Hierochloe odorata can be seen growing in the Grass Garden at Kew.

Pressed and dried specimens of sweet grass are held in Kew's Herbarium, where they are available to researchers by appointment.

A specimen of Hierochloe odorata is held in Kew's Economic Botany Collection in the Sir Joseph Banks Building, where it is available to researchers by appointment.

Distribution
USA
Ecology
Wetlands, mountain slopes, floodplains, marshes and roadsides.
Conservation
Not assessed according to IUCN Red List criteria, but considered to be rare in Britain.
Hazards

See below.

[GB]
Morphology General Habit
Perennial; caespitose. Rhizomes elongated. Culms erect; 20-50 cm long. Ligule an eciliate membrane; 1.5-5(-6.5) mm long. Leaf-blades 18-30 cm long; 4-10 mm wide; aromatic. Leaf-blade margins scaberulous.
Morphology Reproductive morphology Inflorescences
Inflorescence a panicle. Panicle open; ovate; 4-11 cm long. Primary panicle branches spreading; 2-4.5 cm long. Spikelets solitary. Fertile spikelets pedicelled. Pedicels 2-4 mm long; glabrous.
Morphology Reproductive morphology Inflorescences Spikelets
Spikelets comprising 2 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 4-6 mm long; breaking up at maturity; disarticulating below each fertile floret.
Fertile
Spikelets comprising 2 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; 4-6 mm long; breaking up at maturity; disarticulating below each fertile floret.
Morphology Reproductive morphology Inflorescences Bracts Glume
Glumes persistent; similar; reaching apex of florets, or shorter than spikelet; thinner than fertile lemma; shiny. Lower glume ovate; 4-6 mm long; 1 length of upper glume; membranous; 1-keeled; 1-3 -veined. Lower glume apex obtuse. Upper glume ovate; 4-6 mm long; 1.2-1.6 length of adjacent fertile lemma; membranous; 1-keeled; 1-3 -veined. Upper glume apex obtuse.
Morphology Reproductive morphology Flowers Florets
Basal sterile florets similar; male; with palea; attached to and deciduous with the fertile. Lemma of lower sterile floret elliptic; 3.5-4.5 mm long; 1.2 length of fertile lemma; membranous; 1-keeled; 5 -veined; puberulous; ciliolate on margins; obtuse. Palea of lower sterile floret scabrous. Fertile lemma ovate; 3 mm long; cartilaginous; shiny; without keel; 3-5 -veined. Lemma surface pubescent; hairy above. Lemma margins convolute; covering most of palea. Lemma apex acute. Palea elliptic; 0.8 length of lemma; 1 -veined; without keels.
Morphology Reproductive morphology Flowers
Lodicules 2. Anthers 2 (bisexual), or 3 (male); 1-3 mm long (bisexual 1-2mm, male 2-3mm). Stigmas plumose. Ovary glabrous.
Morphology Reproductive morphology Fruits
Caryopsis with adherent pericarp; ellipsoid. Embryo 0.5 length of caryopsis. Hilum linear.
Distribution
Europe: northern, central, southwestern, southeastern, and eastern. Asia-temperate: Siberia, Soviet far east, Soviet Middle Asia, Caucasus, western Asia, China, Mongolia, and eastern Asia. North America: Subarctic, western Canada, eastern Canada, northwest USA, north-central USA, northeast USA, southwest USA, and south-central USA.
Reference
Aveneae. TAC.

>

[KSP]
Use
Strewn on church floors, burned as incense, basketry, local medicine, distilled beverages, ceremonial.

Native to:

Afghanistan, Alaska, Alberta, Aleutian Is., Altay, Arizona, Austria, Baltic States, Belarus, Belgium, British Columbia, Buryatiya, California, Central European Rus, China North-Central, China South-Central, China Southeast, Chita, Colorado, Connecticut, Czechoslovakia, Delaware, Denmark, East European Russia, Finland, France, Germany, Great Britain, Greenland, Iceland, Idaho, Illinois, Indiana, Inner Mongolia, Iowa, Iran, Ireland, Irkutsk, Italy, Kamchatka, Kazakhstan, Khabarovsk, Kirgizstan, Korea, Krasnoyarsk, Labrador, Magadan, Maine, Manchuria, Manitoba, Maryland, Massachusetts, Michigan, Minnesota, Mongolia, Montana, Nebraska, Nepal, Netherlands, Nevada, New Brunswick, New Hampshire, New Jersey, New Mexico, New York, Newfoundland, North Carolina, North Caucasus, North Dakota, North European Russi, Northwest European R, Northwest Territorie, Norway, Nova Scotia, Nunavut, Ohio, Ontario, Oregon, Pennsylvania, Poland, Prince Edward I., Qinghai, Québec, Rhode I., Saskatchewan, South Dakota, South European Russi, Sweden, Switzerland, Tibet, Transcaucasus, Turkey, Tuva, Ukraine, Utah, Vermont, Washington, West Siberia, West Virginia, Wisconsin, Wyoming, Xinjiang, Yakutskiya, Yukon

English
Sweet grass

Anthoxanthum nitens (Weber) Y.Schouten & Veldkamp appears in other Kew resources:

Date Reference Identified As Barcode Type Status
Wolff, G. [3994], Hungary Hierochloe odorata K000307979 isotype
Czernajew, V.M. [s.n.], Ukraine Hierochloe odorata K000808885

First published in Blumea 30: 348 (1985)

Not accepted by

  • Clayton, W.D., Harman, K.T. & Williamson, H. (2006). World Grass Species - Synonymy database The Board of Trustees of the Royal Botanic Gardens, Kew. [Cited as Hierochloe odorata.]
  • USDA, NRCS (2005- continuously updated). Natural Resources Conservation Services Plant Database http://plants.usda.gov/cgi_bin/topics.cgi?earl=checklist.html. [Cited as Hierochloe odorata.]

Literature

Kew Species Profiles

  • World Checklist of Selected Plant Families (2010). The Board of Trustees of the Royal Botanic Gardens, Kew. (Accessed 10 April 2012).
  • Cope, T. & Gray, A. (2009). Grasses of the British Isles (BSBI Handbook No. 13). Botanical Society of the British Isles.
  • Mabberley, D. J. (2008). Mabberley’s Plant-book: a Portable Dictionary of Plants, their Classification and Uses. 3rd edition. Cambridge University Press, Cambridge.
  • Allred, K. W. & Barkworth, M. E. (eds) (2007). Anthoxanthum L. In: Flora of North America Volume 24. (Accessed 16 April 2012).
  • Clayton, W. D., Vorontsova, M. S., Harman, K. T. & Williamson, H. (2006 onwards). GrassBase - The Online World Grass Flora. (Accessed 10 April 2012).

Kew Backbone Distributions

  • Amini Rad, M., Sonboli, A., Ghasemnezhad, A. & Hadian, J. (2012). Hierochloe odorata (Poaceae), a new report from Iran Iranian Journal of Botany 18: 224-225.
  • Grubov, V.I. (2008). Key to the vascular plants of Mongolia (with an atlas) 2: 1-503. Academy of Sciences, Mongolian People's Republic, Ulaan Bator.
  • Wu, Z. & Raven, P.H. (eds.) (2006). Poaceae Flora of China 22: 1-733. Missouri Botanical Garden Press, St. Louis.
  • Takhtajan, A.L. (ed.) (2006). Konspekt Flora Kavkaza 2: 1-466. Editio Universitatis Petropolitanae.
  • Lambion, J., Delvosalle, L. & Duvigneaud, J. (2004). Nouvelle flore de la Belgique du G. D. de Luxembourg, du Nord de la France et des régions voisines, ed. 5: 1-1167. Edition du Patrimoine du Jardin botanique national de Belgique.
  • Malyschev, L.I. & Peschkova, G.A. (eds.) (2001). Flora of Siberia 2: 1-362. Scientific Publishers, Inc., Enfield, Plymouth.
  • Fedorov, A.A. (ed.) (1999). Flora of Russia. The European part and bordering regions 1: 1-546. A.A. Balkema, Rotterdam, Broekfield.
  • Lee, W.T. (1996). Lineamenta Florae Koreae: 1-1688. Soul T'ukpyolsi: Ak'ademi Sojok.
  • Karthikeyan, S., Jain, S.K., Nayar, M.P. & Sanjappa, M. (1989). Florae Indicae Enumeratio: Monocotyledonae: 1-435. Botanical Survey of India, Calcutta.
  • Davis, P.H. (ed.) (1985). Flora of Turkey and the East Aegean Islands 9: 1-724. Edinburgh University Press, Edinburgh.
  • Kharkevich, S.S., Probatova, N.S. & Novikov, V.S. (1985). Sosudistye rasteniia sovetskogo Dal’nego Vostoka 1: 1-383. Izd-vo "Nauka," Leningradskoe otd-nie, Leningrad.
  • Tutin, T.G. & al. (eds.) (1980). Flora Europaea 5: 1-452. Cambridge University Press.
  • Hultén, E.O.G. (1960). Flora of the Aleutian Islands and westernmost Alaska Peninsula: with notes on the flora of Commander Islands, ed. 2: 1-376. Weinheim : J. Cramer ; New York : Hafner Pub. Co.
  • Pavlov, N.V. (ed.) (1956). Flora Kazakhstana 1: 1-354. Alma-Ata, Izd-vo Akademii nauk Kazakhskoi SSR.
  • Roshevitz, R.J. & al. (eds.) (1950). Flora Kirgizskoi SSR 2: 1-315. Frunze : Izd-vo KirgizFAN SSSR.

GrassBase - The Online World Grass Flora
http://creativecommons.org/licenses/by-nc-sa/3.0

Herbarium Catalogue Specimens
'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.
Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

Kew Backbone Distributions
The International Plant Names Index and World Checklist of Selected Plant Families 2021. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
© Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

Kew Names and Taxonomic Backbone
The International Plant Names Index and World Checklist of Selected Plant Families 2021. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
© Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

Kew Species Profiles
Kew Species Profiles
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