Renée Grayer led a walk to Winter Hill and Cock Marsh, starting from the National Trust car park at Cookham, on the morning of Saturday 4 August. The walk started out along a footpath which ran alongside a colourful ditch, where there were tall spikes of Purple Loosestrife, Hemp Agrimony, Great Willowherb, Yellow Loosestrife, Common Fleabane, Gypsywort and Common Valerian. The flower-heads of Wild Angelica, Hogweed and Hemlock Water-dropwort attracted many small insects. Other plants seen here included Square-stalked St John’s-wort, Water Figwort, Orange Balsam, Bulrush and False Fox Sedge. There were a few Banded Demoiselles and the round exit holes of the Hornet Clearwing Moth were noted at the base of a path-side Poplar. The track then led under a railway bridge which had an interesting collection of plants growing out of the old brickwork, including Pale Toadflax, Meadow Crane’s-bill, Wild Marjoram, Wall Rue and Hart’s-tongue Fern. The walk continued along a line of Hornbeam trees, through a kissing gate and out onto the National Trust’s grassland of Winter Hill and Cock Marsh. To the left of the path, the fine chalk grassland of Winter Hill sloped steeply upwards, with flowers including Musk and Dwarf Thistle, Harebell, Small Scabious, Common Bird’s-foot-trefoil, Wild Thyme, Lady’s Bedstraw, Salad Burnet, Clustered Bellflower, Squinancywort, Common Rock-rose, Fairy Flax, Eyebright and Quaking Grass. To the right of the path was Cock Marsh, with meadows beyond stretching for half a mile to the banks of the River Thames. Usually, there are a string of ponds in Cock Marsh, but following prolonged dry weather, these were reduced to damp patches – which made it easier to get close to the special wetland plants. These included Tubular Water-dropwort, Trifid Bur-marigold, Pink Water-speedwell, Marsh Speedwell, Brooklime, Marsh Yellow-cress, Water Forget-me-not, Creeping Jenny, Spear-leaved Orache, Common Water-crowfoot, Water-plantain and Water Dock. Many of the Pink Water-speedwell flower heads had the round galls of the Speedwell Weevil Gymnetron villosulum on the seed capsules. The feathery rosettes of Water-violet were found on an expanse of bare mud. Rarest find of the day was Brown Galingale, a small, tufted, annual sedge which was growing in the cattle-poached mud of the furthest pond. Purple-flowered Water Mint was abundant in the damper areas and visiting butterflies included Gatekeeper, Meadow Brown, Small and Green-veined White and Small Copper. Beneath an isolated Oak just above the edge of the marsh was a long line of red-capped fungi. They had yellow pores on the underside which stained dark blue when rubbed and were tentatively identified as Ruby Bolete Boletus rubellus.
Orange Balsam 
Pale Toadflax 
Pink Water-speedwell 
Tubular Water-dropwort 
Water-violet 
Brown Galingale
Pictures by Rob Stallard
| English Name | Scientific Name |
| Species seen along the ditch: | |
| Yellow Loosestrife | Lysimachia vulgaris |
| Bittersweet | Solanum dulcamara |
| Purple-loosestrife | Lythrum salicaria |
| Bristly Oxtongue | Picris echioides |
| Hogweed | Heracleum sphondylium |
| Prickly Sow-thistle | Sonchus asper |
| Great Willowherb | Epilobium hirsutum |
| Weld | Reseda luteola |
| False Fox-sedge | Carex otrubae |
| Common Valerian | Valeriana officinalis |
| Lords-and-Ladies | Arum maculatum |
| Creeping Thistle | Cirsium arvense |
| Hemlock | Conium maculatum |
| Greater Plantain | Plantago major |
| Pineappleweed | Matricaria discoidea |
| Wild Angelica | Angelica sylvestris |
| Gypsywort | Lycopus europaeus |
| Knotgrass | Polygonum aviculare |
| Meadowsweet | Filipendula ulmaria |
| Pendulous Sedge | Carex pendula |
| Hop | Humulus lupulus |
| Hemp-agrimony | Eupatorium cannabinum |
| Hemlock Water-dropwort | Oenanthe crocata |
| Teasel | Dipsacus fullonum |
| Broad-leaved Dock | Rumex obtusifolius |
| Fool’s Water-cress | Apium nodiflorum |
| Water Figwort | Scrophularia auriculata |
| Common Fleabane | Pulicaria dysenterica |
| Water Mint | Mentha aquatica |
| Bulrush | Typha latifolia |
| Square-stalked St John’s-wort | Hypericum tetrapterum |
| Lesser Water-parsnip | Berula erecta |
| Orange Balsam | Impatiens capensis |
| Clustered Dock | Rumex conglomeratus |
| Wild Carrot | Daucus carota |
| Yarrow | Achillea millefolium |
| Cock’s-foot | Dactylis glomerata |
| Mugwort | Artemisia vulgaris |
| Water-plantain | Alisma plantago-aquatica |
| Agrimony | Agrimonia eupatoria |
| Spear Thistle | Cirsium vulgare |
| Smooth Hawk’s-beard | Crepis capillaris |
| Common Ragwort | Senecio jacobaea |
| Field Bindweed | Convolvulus arvensis |
| Hedge Bindweed | Calystegia sepium |
| Upright Hedge-parsley | Torilis japonica |
| Species on or near Railway Bridge: | |
| Hart’s-tongue | Asplenium scolopendrium |
| Wall-rue | Asplenium ruta-muraria |
| Pale Toadflax | Linaria repens |
| Common Comfrey | Symphytum officinale |
| Wild Marjoram | Origanum vulgare |
| Meadow Crane’s-bill | Geranium pratense |
| Traveller’s-joy | Clematis vitalba |
| White Campion | Silene latifolia |
| Hedge Mustard | Sisymbrium officinale |
| Hornbeam | Carpinus betulus |
| Species found on chalk hill: | |
| Musk Thistle | Carduus nutans |
| Small Scabious | Scabiosa columbaria |
| Fairy Flax | Linum catharticum |
| Squinancywort | Asperula cynanchica |
| Common Bird’s-foot-trefoil | Lotus corniculatus |
| Dwarf Thistle | Cirsium acaule |
| Quaking-grass | Briza media |
| Wild Thyme | Thymus polytrichus |
| Eyebright | Euphrasia agg. |
| Clustered Bellflower | Campanula glomerata |
| Salad Burnet | Sanguisorba minor |
| Rough Hawkbit | Leontodon hispidus |
| Lesser Hawkbit | Leontodon saxatilis |
| Lady’s Bedstraw | Galium verum |
| Harebell | Campanula rotundifolia |
| Common Rock-rose | Helianthemum nummularium |
| Mouse-ear Hawkweed | Pilosella officinarum |
| Thyme-leaved Sandwort | Arenaria serpyllifolia |
| Species found along the ponds: | |
| Trifid Bur-marigold | Bidens tripartita |
| Redshank | Persicaria maculosa |
| Spear-leaved Orache | Atriplex prostrata |
| Lesser Spearwort | Ranunculus flammula |
| Pink Water-speedwell | Veronica catenata |
| Silverweed | Potentilla anserina |
| Brooklime | Veronica beccabunga |
| Marsh Yellow-cress | Rorippa palustris |
| Strawberry Clover | Trifolium fragiferum |
| Welted Thistle | Carduus crispus |
| Common Milkwort | Polygala vulgaris |
| Water Forget-me-not | Myosotis scorpioides |
| Remote Sedge | Carex remota |
| Creeping Jenny | Lysimachia nummularia |
| Tubular Water-dropwort | Oenanthe fistulosa |
| Marsh Speedwell | Veronica scutellata |
| Common Water-crowfoot | Ranunculus aquatilis |
| Water-violet | Hottonia palustris |
| Common Sorrel | Rumex acetosa |
| Brown Galingale | Cyperus fuscus |
| Water Dock | Rumex hydrolapathum |
| Butterflies: | |
| Small White | |
| Green-veined White | |
| Small Copper | |
| Common Blue | |
| Red Admiral | |
| Gatekeeper | |
| Meadow Brown |
List by Renée Grayer