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flouve odorante, foin d'odeur, large sweet grass, sweet vernal grass, vernal sweetgrass

California sweet grass, vanilla grass

Habit Plants perennial. Plants perennial; loosely cespitose or the culms solitary, rhizomes elongate, 1-3 mm thick.

(10) 25-60(100) cm, erect, simple or sparingly branched.

(4)60-90 cm.


scabrous to scabridulous;

ligules 1.5-4(6) mm, rounded to truncate;

blades 20-40 cm long, (3)5-15 mm wide, flat, rather stiffly erect, narrowing to the base, glabrous, often glaucous, veins widely spaced, cross venation evident on the abaxial surfaces;

flag leaf blades 3.5-10 cm.


(3) 4-14 cm, the spikelets congested;

lowermost branches 10-25 mm;

pedicels 0.5-1 mm, pubescent.

8-13 cm long, (1)2-6 cm wide, diffuse, with slender, often drooping branches and 3+ spikelets per branch.


6-10 mm;

lower glumes 3-4 mm;

upper glumes 8-10 mm;

sterile florets 3-4 mm, awn of the first floret 2-4 mm, awn of the second floret 4-9 mm, equaling or only slightly exceeding the upper glumes;

bisexual florets 1-2.5 mm;

anthers 2, (2.9)3.5-4.8(5.5) mm.

4.5-6 mm, tawny or green to olive-green, sometimes infused with purple;

rachilla internodes 0.2-0.5 mm, glabrous.


subequal, equaling or slightly exceeded by the apices of the bisexual florets;

lower glumes 4.5-5 mm long, 0.7-1 mm wide;

upper glumes 3.5-5.2 mm long, 1-1.8 mm wide;

lowest 2 florets staminate;

lemmas usually mostly glabrous on the body, sometimes scattered-pubescent, scabridulous near the apices, margins usually pilose, apices rounded and shallowly bilobed, unawned or awned, awns to 1 mm;

first lemma 4-5 mm long, 0.75-1 mm wide, length more than 5 times width, narrowly elliptic;

bisexual lemmas 3.5-4.5 mm, margins pilose, particularly distally;

anthers 2-3.5 mm.


0.5-1 mm, pilose-ciliate, sometimes absent;

ligules 2-7 mm, truncate;

blades 1-31 cm long, 3-10 mm wide.


= 10,20.

= 42.

Anthoxanthum odoratum

Hierochloe occidentalis

from FNA
AK; AL; AR; CA; CO; CT; DC; DE; GA; ID; IL; IN; KY; LA; MA; MD; ME; MI; MO; MS; NC; NH; NJ; NM; NY; OH; OR; PA; RI; SC; TN; TX; VA; VT; WA; WI; WV; HI; BC; LB; NB; NS; ON; PE; QC; Greenland
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from USDA
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Anthoxanthum odoratum is native to southern Europe. In the Flora region, it grows in meadows, pastures, grassy beaches, old hay fields, waste places, and openings in coniferous forests, occasionally in dense shade or as a weed in lawns. It is most abundant on the western and eastern sides of the continent, and is almost absent from the central region. In southern British Columbia, it is rapidly invading the moss-covered bedrock of coastal bluffs, and will soon exclude many native species. Diploids (In = 10) have been referred to A. odoratum subsp. alpinum (Á. Löve & D. Love) Hulten. Because the two ploidy levels can be distinguished only through cytological examination (Hedberg 1990), the two subspecies are not recognized here.

Anthoxanthum odoratum was often included in hay and pasture mixes to give fragrance to the hay, but this practice is waning. The aroma is released upon wilting or drying. By itself, the species is unpalatable because of the bitter-tasting coumarin.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Anthoxanthum occidentale grows in moist to fairly dry forested areas, from Klickitat County, Washington, south to the coastal mountains of San Luis Obispo County, California. Its long flag leaf blades and more elongate spikelet parts make it easier to distinguish from A. hirtum than the key suggests.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 24, p. 759. FNA vol. 24, p. 762.
Parent taxa Poaceae > subfam. Pooideae > tribe Poeae > Anthoxanthum Poaceae > subfam. Pooideae > tribe Poeae > Anthoxanthum
Sibling taxa
A. arcticum, A. aristatum, A. hirtum, A. monticola, A. nitens, A. occidentale
A. arcticum, A. aristatum, A. hirtum, A. monticola, A. nitens, A. odoratum
Synonyms A. odoratum subsp. alpinum Hierochloe occidentals
Name authority L. (Buckley) Veldkamp
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