Common Name: Spinifex, Porcupine Grass
Description: Coarse tussock or hummock-forming perennials, hummocks sometimes ring-like with age, culms branched and leafy.
Leaves with sheath glabrous or hairy; ligule a rim of hairs, short, the orifice sometimes with woolly hairs; blade folded in the bud, at first flat but permanently folded during first stress period, usually acute, often sharp-pointed, tough, rigid, sometimes producing resin.
Inflorescence paniculate, open, or racemose. Spikelets solitary, pedicellate, disarticulating above the glumes and between the lemmas; florets numerous, bisexual, the upper sometimes sterile. Glumes subequal, acuminate, keeled, 1–many-nerved. Lemmas 2–many, 3-nerved or with several nerves in 3 groups, rounded on the back, nerves or groups of nerves terminating in 3 lobes or teeth, sometimes emarginate; palea 2-keeled, keels usually ciliolate.
Distribution and occurrence: World: c. 45 species, endemic Australia. Australia: all mainland States.
Hummocks of so called Spinifex grasses (some are species of another genus, Plectrachne) comprise the bulk of the vegetation of much of arid inland Australia. Key based on Burbidge (1953).Derivation: from the Greek words for 'three' and 'teeth' referring to the lemma of some species.
Text by S.W.L., Whalley, R.D.B. & Wheeler, D.J.B.
Taxon concept: Grasses of New South Wales, Fourth Edition (2008).
| | Key to the species | |
| 1 | Lobes of the lemma as long as or longer than the base of the lemma | Triodia basedowii |
| Lobes of the lemma shorter than the body of the lemma, 3-lobed or forming a shallow notch at the apex with a short or minute mucro in the sinus | 2 |
| 2 | Leaves with sheath glabrous or glaucous and minutely pubescent, resin not produced; lemma with a shallow notch occasionally bearing a minute mucro between lobes | Triodia scariosa |
| Leaves with sheath hirsute or fringed with hairs on the upper margins, always producing resin
Back to 1 | Triodia mitchellii |
|
