Scale bar is 1cm.

Spear-grasses - natives and introduced Austrostipa, *Nassella and *Amelichloa

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Other spear grasses

Family. Poaceae (Grass family).

Spear grasses are tall (over a metre) or medium-tall (about 40cm). The flowers are clustered into a spray. The florets have two glumes and a single spikelet. The hard lemma encircles the seed, and has a single stout awn rising from the tip of the lemma. The awn is at first almost straight, but on drying, is once or twice bent. Glumes have at least three veins.

Six or more species grow near Castlemaine. The size and character of the ligule, the size of the glumes, lemmas, paleas and awns, the way the awn bends, the hairiness of the leaves, lemmas and awns, the length of the callus, and the shape of the flower cluster (open or contacted) can be important in distinguishing between species. There is much overlap in these characters and identification is not always easy.

Some spear grasses have a cluster of hairs at the tip of the lemma. In native species the hairs are similar in width to those on the lemma. Introduced spear grasses (Nassella) have thicker hairs that are united to form a crown. The crown of Serrated Tussock may be inconspicuous.

Introduced spear-grasses

tusssock Serrated Tussock (*Nassella trichotoma) Awn plump. Lemma 3mm long. Weed.
Texas Needle-grass (*Nassella leucotricha)
Crown with a ring of bristles. Lemma 6-9mm long (excluding awn). 1st glume 10-17mm long. Weed.
Chilean Needle-grass (*Nassella neesiana)
Crown has small teeth. Lemma 6-9mm long (excuding awn). 1st glume 16-25mm long. Weed.
Espartillo (*Amelichloa caudata)
Awn less than 2cm long. Weed.

Lemmas with a ring of hairs at the summit             Awns dry to a sickle shape

spear-grass Crested Spear-grass (Austrostipa blackii) Awn more than 2cm long. Lemma relatively stout, so that glumes bulge around the floret; flower spray open.
A stuposa Tasmanian Spear-grass (Austrostipa stuposa) Awn more than 2cm long. Lemma slender. Hairs at awn-base 1-3mm long, awn with hairs 0.5-1.5mm.
A bigenuculata Kneed Spear-grass (Austrostipa bigeniculata) Awn more than 2cm long. Awn with very short hairs (<2mm), lemma evenly hairy. Basalt areas.
A gibbosa Spear-grass (Austrostipa gibbosa) Short, blackish, hairy lemma with swollen side at the tip. Uncommon.
spear-grass Rough Spear-grass (Austrostipa scabra ssp falcata) To 50cm high. Open flower cluster. Leafy at base with slender (1mm or less) cylindrical leaves. Very common.
spear-grass Knotty Spear-grass (Austrostipa nodosa) To about a metre high. Leaves spreading, more than 1mm wide. Flower cluster rather sparse.

Awn twice-bent when dry

A mollis Supple Spear-grass (Austrostipa mollis) Very common. Hairs on awn 1mm or more, hairs appear to spiral around the awn. Flower spray dense.
A semibarbata Fibrous Spear-grass (Austrostipa semibarbata) Not common. Hairs on awn 0.3-1mm long, not appearing to spiral. Flower spray moderately dense. Summit of lemma hairless and granular.
A oligostachya Fine-head Spear-grass (Austrostipa oligostachya) Hairs on awn less than 0.8mm, lemma usually with two small lobes at the tip. Flower spray open. Glumes and leaf-sheaths purplish. Not common.
A rudis Veined Spear-grass (Austrostipa rudis) Glumes are eroded at the tip. Awns hairless or with very short hairs. South of Castlemaine.
A densiflora Fox-tail Spear-grass (Austrostipa densiflora) Short dense flower cluster. Lemmas are small (5.5-7mm, excluding the awn). Uncommon.