Description: Small, rhizomatous, glabrous perennials, forming dense mats or cushions. Culms trigonous, very short, mostly hidden amongst leaf sheaths.
Leaves numerous, often flattened and distichous; sheath open, with apex often produced in small rounded auricles; pseudopetiole slightly concave to channelled, narrower than sheath or blade, rigid; blade slightly twisted relative to pseudopetiole, rigid, flatter than pseudopetiole.
Inflorescence small, often ± concealed among leaves but still longer than culm, consisting of 1–6 spikelets on short branches at 1–3 nodes; involucral bracts leaf-like, with closed sheaths. Spikelets compressed, with 2–5 glumes, enclosing a single bisexual flower. Glumes leaf-like, outermost longest. Hypogynous scales in 2 alternating whorls, flat, persistent on rachilla after nut falls. Stamens 3. Style 3-fid.
Nut trigonous to terete, smooth.
Distribution and occurrence: World: 14 species, at high altitudes in Australasia, South America, Malesia, Pacific islands. Australia: 5 species (4 species endemic), N.S.W., Vic., Tas.
Leaf blades often have distinctive patterns of longitudinal bands of stomates (visible as whitish dots with a hand lens) and faint to obvious longitudinal ribs on the adaxial surface.
Text by K. L. Wilson
| ||Key to the species|| |
|1||Leaf blades with a median stomate-less longitudinal band adaxially between 2 faint or obvious ribs; apex of nut acute||Oreobolus distichus|
|Leaf blades entirely covered with stomates adaxially||2|
|2||Leaf blades with 3–6 evenly spaced ribs adaxially; apex of nut obtuse or truncate||Oreobolus pumilio|
|Leaf blades without or with 1 or 2 faint ribs adaxially; apex of nut an elongated cone, collapsing when mature|
Back to 1