Saturday, 8 October 2011

Grasses @ Broga Hill

Imperata cylindrica, commonly known as blady grass (Australia), speargrass (Nigeria), silver spike (S.Africa), cogon grass (USA), lalang (in Malay), 茅草 (in Mandarin), etc , is a species of grass ( Poaceae ), native to east and southeast Asia, India, Micronesia, Australia, and Africa.

It is first describe by Linnaeus in 1759 as Lagurus cylindricus.  French entomologist and botanist Palisot de Beauvois renamed it to current accepted name Imperata cylindrical.  
Its other synonyms include : Calamagrostis lagurus, Imperata allang, I. arundinacea, I. koenigii, I. pedicellata, I. sieberi, I. thunbergii, Saccharum cylindricum, S. europeaum, S. loenigii, S. laguroides, Sl sisca, S. thunbergii.

It grow from 0.6 -3 m tall.  
The leaves are about 2cm wide, and narrow to a sharp point at the tip.  Leaf margins are finely toothed and embedded with sharp silica crystals.  Upper surface is hairy near the base, underside is usually hairless.
Roots are up to 1.2m deep.
Propagation via seeds and rhizomes.
It can withstand draught and fire, regenerates quickly after fire.

Imperata cylindrica is found in areas where the soil has been disturbed, such as roadsides, building sites, agricultural land, ex-logging area, cleared jungle.  Once established it often form dense monocultues.

Despite considered weeds in most part of the world, it is cultivated in some area for commercial uses.
In Papua New Guinea, it is used for thatching the roofs of traditional homes.
It s planted as ground cover for soil stabilization to prevent erosion.
It is also used in paper-making, and weaving into mats and bags.
In traditional Chinese medicine, it is use for its medicinal properties for astringent, febrifuge, diuretic, tonic and styptic actions.
Some cultivars are planted as ornamental plants, including the red-leaved ‘Red Baron’
Young inflorescence and shoots may be eaten cooked.
Roots are edible containing starch and sugars.

Pennisetum polystachyon also known as feather Pennisetum, mission grass, rumput gajah ( in Malay ), ekor kucing ( in Malay ),  狼尾草 ( in Mandarin ) etc.

Pennisetum polystachyon also known as P. triticoides, P. setosum, Panicum polystachyon, Panicum longisetum.

Originated from Old World tropics, probably India and tropical Africa.

It is an annual, simple erect in large clumps, capable to grow up to 2 - 3 m in height.
Leave are linear with narrow blade up to 45cm long.
Inflorescence is cylindrical with dense spike, yellow-brown, 10 – 26 cm long.
Propagation via seeds.  Seeds are dispersed by flowing water, strong winds, or they may adhere to clothing or animal.
It canot stand heavy grazing.  However, it tolerates fire. 
It is capable to adapt to wide range of soil type.

In Thailand, India  and Fiji, it is used as green fodder.
It is planted at slopes to prevent erosion.
P. polystachyon easily invades both wasteland and cultivated land,  and of course moutainous land too. 
At many places, it is regarded as noxious weed.

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