Brachypodium pinnatum, tor-grass or heath false brome is a plant in the grass family, with a widespread distribution in temperate regions of the Northern Hemisphere.

Tor-grass is dominant but in small areas.

The site is grazed to prevent the dominant growth of Upright Brome and Tor-grass.

In all of these habits Tor-grass (Illustration 2), the butterfly's sole food plant and that on which it lays eggs, is widespread.

The areas of the quarry which are now grassed support Tor-grass and Upright Brome mixed with other species.

The traditional management method of sheep grazing is used to control the growth of Tor-grass and Upright Brome.

Tor-grass (Brachypodium pinnatum)

The limestone grassland consists largely of Upright Brome with Tor-grass on steeper parts where site is ungrazed.

The grassland is dominated by grasses such as Upright Brome, Sheep's Fescue, and there is little Tor-grass.

The grassland includes Upright Brome, Tor-grass, Sheep's Fescue and a range of plants which flourish on calcareous soils.

The grassland plateau supports Tor-grass, Upright Brome, Sheep's Fescue and Quaking Grass.

This is dominated by Tor-grass, Upright Brome, Meadow Oat-grass, Sweet Vernal-grass and Quaking Grass.

The pasture faces south to south-east and species include Upright Brome, Tor-grass, Red Fescue, Meadow Oat-grass and Quaking-grass.

Ungrazed calcareous grassland makes up the northern section of the site, which consists mainly of Upright Brome, Tor-grass, Common Rock Rose and Old Man's Beard.

The females lay their eggs in rows of 5 to 6 (although as many as 15 have been recorded) on the flower-sheath of Tor-grass (Brachypodium pinnatum), preferring the dead sheaths of tall plants.

The larvae feed on Brachypodium pinnatum.

The larvae feed on various grasses such as Brachypodium pinnatum en Bromus madritensis.

Tor-grass (Brachypodium pinnatum)

Tor Grass (Brachypodium pinnatum)

The dominant chalk grassland community at Park Gate Down is CG4 Brachypodium pinnatum.

In a few years, the sward may become dominated by the coarse tussock-forming grass, Brachypodium pinnatum, and eventually the vegetation turns into some form of scrub and possibly woodland.

NVC community CG4 (Brachypodium pinnatum grassland) is one of the calcicolous grassland communities in the British National Vegetation Classification system.

The larvae feed on Brachypodium pinnatum, Brachypodium sylvaticum, Carex humilis, Carex montana, Dactylis glomerata, Holcus and Poa trivialis.

The main chalk grassland communities are CG4 Brachypodium pinnatum and CG5 Bromus erectus - Brachypodium pinnatum.

The females lay their eggs in rows of 5 to 6 (although as many as 15 have been recorded) on the flower-sheath of Tor-grass (Brachypodium pinnatum), preferring the dead sheaths of tall plants.

The larvae feed on Agrostis, Avena fatua, Brachypodium pinnatum, Brachypodium sylvaticum, Calamagrostis, Deschampsia cespitosa, Festuca arundinacea, Milium effusum and Poa badensis.

The larvae mainly feed on Molinia caerulea, but have also been recorded on Arrhenatherum, Brachypodium pinnatum, Brachypodium sylvaticum, Calamagrostis arundinacea, Diarrhena americana, Carex, Melica and Poa.

Phleum (Phleum pratense), Poa (Poa annua, Poa trivalis), Festuca rubra, Bromus erectus, Dactylis, Brachypodium pinnatum, Agrostis capillaris.

The downland is classified as CG4 Brachypodium pinnatum and CG5 Bromus erectus - Brachypodium pinnatum calcareous grassland with smaller areas of CG2 Festuca ovina - Avenula pratensis grassland.