Grass of the Month for August 2013
The individual spikelets are similar to other Agrostis spikelets - As in all Agrostises, the two glumes are longer than the single floret and normally enclose it.
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| Like other Agrostises, A gigantea has two glumes and one floret and the lemma and the palea are both translucent. |
The BSBI map shows it has not been found in the hectads east and north of Settle (mostly sheep grazed hills) - which perhaps explains why I do not see it often. - but it is common in the south.
As an arable weed it can be seen at fence boundaries, where it uses the fencing for support - it is a straggling pant. The fence also prevents the grass getting mown/ploughed up.
The emerging leaf is rolled, the stems are narrow, the blades are thin and narrow (2-7 mm wide), the ligule is medium to long,
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| It has a long ligule - this picture was taken at Tems Beck Giggleswick 30 June 2013 |
It has rhizomes.
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| Agrostis gigantea has rhizomes (Tems Beck) |
It can be distinguished from other Agrostis's because:
Agrostis vinealis and Agrostis canina have very narrow leaves (less than 2 mm wide)
Agrostis capillaris (which has rhizomes) has has short ligules
Agrostis stolonifera (which has long ligules and blades 2-7 mm wide) has stolons not rhizomes. A stolonifera also has a rather small compact panicle with the panicle branches pointing up at an angle of 45 degrees.
As the year proceeds, A gigantea shoot grow longer and they branch 20 or 50 cm above ground with extravaginal branching - i.e. a side branch pokes a hole through the sheath and there are then two stems.
See a new shoot breaking though the sheath,
on part of the main shoot well above ground level.
(Tems Beck, 30 June 2013)
(Tems Beck, 30 June 2013)
By flowering time (August) A gigantea has really big spreading panicles.
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| Here is a panicle. It is actually very big. (Pot Hole Lane, Malham Tarn, 7 Aug 2013) |
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