Lewes Downs IPA
Location: North of the A27(T), 3 km south east of the town of Lewes, and 1 km west of Glynde village.
Grid Reference: TQ 441 090
Lewes Downs IPA has been recognised as one of 165 Important Plant Areas in the UK
The key features of this IPA are:
Semi-natural calcareous grasslands, sometimes with scrub
The site is a good example of ancient, traditionally managed chalk downland, forming part of the South Downs.
It is important for the extremely rich chalk grassland and scrub vegetation, which contains a number of southern and oceanic-southern species as well as an important assemblage of rare and scarce orchids.
The richest parts of Lewes Downs are the Old Chalk Pit, Bible Bottom, Malling Combe and parts of Mount Caburn. Here the sward is dominated by sheep’s fescue and upright brome grasses which form a springy turf with an abundance of characteristic herbs of chalk grassland. Salad burnet, horseshoe vetch, yellow-wort and sqinancy wort are widespread, and in Caburn Bottom an exceptional quantity of wild marjoram occurs, an important food plant for the chalkhill blue butterfly.
A number of plants occupying a strictly southern distribution within the British Isles are found on the warm south facing slopes of Malling Combe and Mount Caburn including chalk milkwort and round-headed rampion. One of the largest British colonies of the burnt orchid occurs on the upper slope of Mount Caburn, intermittently appearing with the nationally rare early-spider orchid.
The orchid flora, in Caburn Bottom and on the steeper slopes of the chalk pits in the far north of the site, is exceptional for its variety and for the number of individual plants. Bee, fly, frog and musk orchids may be found here. Areas of ash woodland occur on the eastern edge of the site and south of Malling Combe, where sycamore becomes locally dominant. Beneath this canopy hawthorn and elder form a shrub layer with a ground flora of dog’s mercury and ground ivy. Mezereon, an unusual shrub with a restricted distribution also occurs here.