Wildflowers and insects of Maidenhead and Cookham Commons

The commons of Maidenhead and Cookham offer an abundance of different habitats and niches and are home to a wide variety of wildflowers and insects , including rarities such as the White-letter Hairstreak butterfly and the diminutive Brown Galingale sedge.

The commons are made up of just under 500 acres of grassland including a Site of Special Scientific Interest (SSSI) at Cock Marsh and 16 acres of open chalk grassland slope at Winter Hill. The remaining 340 acres of the commons are wooded with 250 of these making up the woodland of Maidenhead Thicket. 

Wildflowers and where to find them

Many common meadow flowers can be spotted across the commons of Maidenhead and Cookham. With Meadow buttercup, Bird’s-foot trefoil and Common Mouse-ear prevalent throughout the grasslands at Pinkneys  Green, Pinkneys Drive and the Commons of Cookham Dean.

A large swathe of herb-rich wildflower meadow at Pinkneys Drive can be found over the road from the car park. Planted by the Copas Partnership in the late 1990s this area is awash with a sea of Cowslips during early spring.

Cowslips, Pinkneys Drive
Cowslips at Pinkneys Drive, Maidenhead, Berkshire

The ponds that occupy the old clay pits of the Brick and Tile Works are abundant in Frogbit, with the occasional white Water-lily and Water-plantain too. Whereas the woodlands are a great place to see Common-spotted orchid and Dog rose. 

Water Lily, Brick & Tile Works
Water Lily at Maidenhead Brick and Tile Works, Berkshire

The rides  of Maidenhead Thicket are well worth a visit to see how their structure and species compositions change from season to season. Rides are linear woodland clearances that usually centre about paths. Our rides are managed by the Maidenhead and Cookham Commons volunteer and ranger team to provide valuable woodland edge habitat, increasing the structural complexity and diversity of the Thicket.

Maidenhead Thicket is a great place to orchids such as the Fly and Common-spotted orchids, as well as Green Hound’s-tongue, Eyebright and Bugle.

Common spotted orchids at Robin Hood's Arbour, Maidenhead Thicket
Common spotted orchids on Maidenhead Thicket

The marshy grasslands and seasonal ponds of Cock Marsh are particularly notable for the presence of Marsh stitchwort and Tubular water-dropwort. The pond margins of Cock Marsh are one of only twelve sites in the country where the rare sedge species, Brown galingale  can be found. Brown galingale is a red listed species that flourishes at the edges of ponds that are disturbed by grazing livestock.

Brown galingale on Cock Marsh
Brown galingale on Cock Marsh

The steep slopes that mark the edge of the Thames floodplain at Cock Marsh support a high quality calcareous grassland community that is abundant in Salad burnet, Thyme, Squinancywort, and Common rock rose. Other notable species include Fairy flax, Hoary plantain and Pyramidal and Bee orchids.


Our two principle sites for butterflies on the commons are Cock Marsh and Maidenhead Thicket, both of which provide very different habitat types that are utilised by an array of butterfly and moth species. Common species that can be spotted across both sites and much of the commons include the Meadow Brown, Ringlet, Marbled White, and Brimstone.
On Cock Marsh and Winter Hill can be found the occasional migrant Clouded Yellow along with chalk grassland adapted species, such as the Green Hairstreak, Chalkhill Blue and Brown Argus.

Pale clouded yellow butterfly, Pinkneys Drive wildflower meadow
Pale clouded yellow butterfly, Pinkneys Drive wildflower meadow

Recent ride improvement works throughout the Thicket has led to an increase in prime butterfly habitat, much of which has been utilised by woodland edge adapted species such as the comma, silver washed fritillary, gate keeper and purple hairstreak.

Purple Hairstreak butterfly, Maidenhead Thicket
Purple Hairstreak butterfly, Maidenhead Thicket

Regular butterfly transects are  carried out at Winter Hill, Cock Marsh and Maidenhead Thicket by our team of surveying and monitoring volunteers. A transect is a line across a habitat, or part of a habitat. It can be as simple as a string placed in a line on the ground. The volunteer then records the number of occurrences along the line of whatever species they find.
We also work in partnership with Butterfly Conservation on their Disease Resistant Elm project, with Maidenhead Thicket being a principle site for the planting of elm trees that are resistant to Dutch elm disease. The aim of the project is to encourage the rare White-letter hairstreak butterfly whose caterpillars feed on elm.

White-letter Hairstreak butterfly at Maidenhead Thicket
White-letter hairstreak butterfly taken by Ian Wilson at Maidenhead Thicket


Previous surveys have identified the nationally scarce downy emerald dragonfly at the ponds at the Brick and Tile Works, preferring water bodies with overhanging trees and a carpet of leaf litter on the pond floor. The site is also home to common species such as the large red and common blue damselfly, along with brown hawker, all of which are abundant across many of the commons.

Large Red damselfly, Brick & Tile Works
  Large Red Damselfly at Maidenhead Brick and Tile Works, Berkshire

Other flies

As well as the butterflies and dragonflies of the commons many of our sites are home to other rarities, such as the scarce hoverflies Didea fasciata and Volucella inanis. Maidenhead Thicket is also home to a breeding population of the wasp mimic crane fly Ctenophora flaveolata, which relies entirely on the decaying heartwood of veteran beech trees.

Rare cranefly Ctenophora flaviolata, Maidenhead Thicket
Rare cranefly Ctenophora flaviolata, Maidenhead Thicket


The nationally scarce oak jewel beetle can be found at both Winter Hill Road Woods and Maidenhead Thicket where it develops within veteran oak trees as a larva, feeding on oak leaves in the crown of the trees after hatching. The species is a notable wood-decay invertebrate which benefits from the sympathetic management of woodlands for deadwood habitat.

Similarly, stag beetle larvae are often found by our volunteers on task days within Maidenhead Thicket, putting a halt to whatever we are doing while we lovingly construct a new home for what is surely our most spectacular beetle.