Hordeum distichon*

Hordeum distichon* Linn. Sp. Pl. 85 (1753).

Classification. (GPWG 2001) : Subfamily Pooideae. Tribe Triticeae.

Type of Basionym or
Protologue Information
: France: 'pl. de l'ouest de la France', 29 June
1879, Gadecau s.n. (HT: ?; NT: BM).

Key references
(books and floras):
[2002] D.Sharp & B.K.Simon, AusGrass, Grasses of
, [2006] J.Jessop, G.R.M.Dashorst, F.M.James, Grasses of South
(268), [2008] S.W.L.Jacobs, R.D.B.Walley & D.J.B.Wheeler, Grasses
of New South Wales
(278), [2009] A.Wilson (ed.). Flora of Australia,
Vol 44A. Poaceae 2 (114).

[2006] J.Jessop, G.R.M.Dashorst, F.M.James, Grasses of South Australia  (268, fig. 207), [2008] S.W.L.Jacobs,
R.D.B.Whalley & D.J.B.Wheeler, Grasses of New South Wales, 4th edn

Habit. Annual.
Culms erect, 29–120 cm tall, 3–5 -noded. Leaf-sheath auricles present. Ligule
an eciliate membrane, 0.25–2 mm long, hyaline, truncate. Leaf-blades flat,
10–45 cm long, 3–12 mm wide.

Inflorescence solid, a spike. Rhachis tough.

Spikelets. Spikelets
sessile, 1 in the cluster. Companion spikelets pedicelled, 2 in the cluster.
Companion spikelets developed, containing empty lemmas or male, 10 mm long.
Fertile spikelets 1-flowered, comprising 1 fertile floret(s), without rachilla
extension, lanceolate, dorsally compressed, 8–12 mm long.

Glumes. Glumes
similar. Lower glume subulate or linear or oblong, chartaceous. Lower glume
apex muticous or awned. Upper glume linear, 4–5 mm long. Upper glume apex

Fertile lemma 5.75–12 mm long, without keel, 5 -nerved. Lemma apex awned, 1
-awned. Median (principal) awn 67–130 mm long overall. Anthers 3.

: Europe, Temperate Asia, Tropical Asia, Australasia, North
America, and South America.

: Western Australia, South Australia, Queensland, New South
Wales, Victoria, Tasmania.

Western Australia:
Drummond, Eyre, Roe, Avon. South Australia: Lake Eyre, Flinders Ranges,
Eyre Peninsula, Northern Lofty, Yorke Peninsula, Southern Lofty. Queensland:
Cook, Darling Downs, Moreton. New South Wales: Central Coast,
North-Western Slopes, Central-Western Slopes, South-Western Slopes,
North-Western Plains. Victoria: Murray Mallee, Wimmera, Riverina,
Midlands, Volcanic Plain, Gippsland Plain. Tasmania: No region given.

Native to Europe and naturalized in all Australian states except N.T. where it
is generally restricted to roadsides. Flowers Sept.-Dec.

AVH 2011


Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith