Astrebla
Astrebla is a genus of grasses ( Poaceae ), which is endemic to Australia, where Mitchell Grass is called.
Features
The species are perennial grasses Horst ( tussock ). The stalks are 30 to 90 ( -120 ) cm tall. They have a distinct rhizome with many short, thick, branched rhizomes. For this rootstock spring the main shoots, from these, the other side shoots.
The leaf blade is rolled in bud position. The ligule ( ligule ) is a lash.
The inflorescence is a terminal spike or spike- like raceme, which is single or double. The spikelets are sitting, standing alone on the axis. The two to nine flowers per spikelet are hermaphroditic, only the top one is often reduced. The glume are slightly unequal, keeled, pointed and oblong to elliptical. The lemmas are longer than the glumes, leathery, deep -lobed with a rounded back. Your base is hairy, midrib running a stiff, often curved awn from. The palea shorter than the lemmas and have two ciliated keels.
There are C4 plants. The basic chromosome number is x = 10, 2n = 40, so the plants are tetraploid.
Dissemination
The genus is endemic to Australia and covers about 450,000 km ² especially in the west of Queensland. The main distribution area is between 18 and 28 ° south latitude. The annual rainfall is 250-550 mm. The four types often occur together and dominate the tussock.
Ecology
The species are very resistant to drying out and also against grazing ( except horses). They are frost tolerant and tolerate occasional fire. They grow on heavy clay soils, where no trees occur.
The nests are 20 to 30 years old and bear fruit at this time due to the irregular rains only once or twice.
System
Astrebla belongs to the tribe Cynodonteae within the subfamily Chloridoideae. There are four types:
- Astrebla lappacea ( Lindl. ) Domin
- Astrebla squarrosa C. E. Hubb.
Relevance to humans
The Tussock grasslands are grazed heavily today. Are typical densities of a sheep on 1.22 acres. The yield is depending on rainfall 400-2250 kg per hectare.
Sources and further information
The article is based on the following sources:
- Grassland Species Profiles FAO
- Astrebla on New South Wales Flora Online
- Mitchell grass - Australia 's own grass