On the steep grassy slopes above the River Avon, Bristol rockcress ("Arabis scabra") which is unique to the Avon Gorge can be seen flowering in April; orchids and western spiked speedwell ("Veronica spicata") are common in June and July. In autumn the woodland hosts over 300 species of fungi. Bilberry, a scarce plant in the Bristol area, is found in Leigh Woods, as is the parasitic plant yellow bird's-nest "(Monotropa hypopitys)". Lady orchid "(Orchis purpurea)" was discovered here in 1990, in Nightingale Valley; there is doubt as to whether this was a wild plant or an introduction. Green-flowered helleborine "(Epipactis phyllanthes)" is found on the western side of the gorge, in a wooded area next to the towpath below Leigh Woods.