Tetrarrhena oreophila

Tetrarrhena oreophila D.I.Morris. Rec. Queen Vic. Mus. 55: 4 (1977).

Classification. (GPWG 2001) : Subfamily Ehrhartoideae. Tribe Ehrharteae.

Type of Basionym or Protologue Information: Tasmania:  Morris (K iso).

Recent synonyms: Ehrharta oreophila.

Key references (books and floras): [2002] D.Sharp & B.K.Simon, AusGrass, Grasses of Australia, [2009] A.Wilson (ed.). Flora of Australia, Vol 44A. Poaceae 2 (376, 377 as var. oreophila, & var. minor).

Habit. Perennial. Rhizomes present. Stolons present. Culms erect or decumbent, stature slender to delicate, 5–30 cm tall. Mid-culm internodes glabrous. Leaf-sheath auricles absent. Ligule an eciliate membrane or a fringed membrane, a ciliolate membrane, 0.2–1.2 mm long, membranous, lacerate. Leaf-blades filiform, flat or involute, 1–8 cm long, 0.5–1.7 mm wide. Leaf-blade surface glabrous.

Inflorescence. Inflorescence solid or compound, a raceme. Panicle 0.7–3 cm long. Racemes 1, 1.5–3 cm long, bearing 6–10 fertile spikelets on each.

Spikelets. Spikelets sessile or pedicelled. Fertile spikelets 1-flowered, comprising 2 basal sterile florets, comprising 1 fertile floret(s), without rachilla extension, oblong, laterally compressed, 4–6.5 mm long. Rhachilla internodes brief up to lowest fertile floret.

Glumes. Glumes similar, thinner than fertile lemma. Lower glume elliptic, hyaline, without keels, 1 -nerved. Upper glume oblong, 1.4–2.4 mm long, hyaline, without keels, 1–3 -nerved. Florets. Basal sterile florets 2 or more, barren, without significant palea. Lemma of lower sterile floret 66 % of length of spikelet, coriaceous, 1-keeled, 5 -nerved, mucronate. Lemma of upper sterile floret 5 mm long, mucronate.

Fertile lemma 2.7–4 mm long, keeled, 3–5 -nerved. Palea 1 -nerved. Lodicules present. Anthers 2.

Continental Distribution: Australasia.

Australian Distribution: Tasmania.

Tasmania: West Coast, Central Highlands, South West, Mt Field.

Notes. Tasmanian endemic.

Infra -specific taxa: var. oreophila, var. minor.

Leaf blades inrolled; lower glume 1.3–1.8 mm long, acute; bisexual lemma 3.5–3.8 mm long T. oreophylla var. oreophylla

Leaf blades flat; lower glume 0.7–0.9 mm long, obtuse; bisexual lemma 2.7–3.3 mm long T. oreophylla var. minor


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