Not to be semantically confused with : Cornflower (Centaurea cyanus) [a plant with similar-sounding name], nor with garden flowers belonging to the Genus Echinacea which also have the same common name of 'Coneflowers' and which have a much-more pronounced upside-down shuttlecock appearance with reflexed ray florets and central domed disc florets but which are usually lilac in colour and have no wild presence in the UK [both these belong to the same Dandelion & Daisy Family (Asteraceae) as Rudbeckia].
Lookee-Likees : Coneflowers belonging to the Echinacea genus (mentioned above) which have no wild presence in the UK, being garden flowers only. But whereas Rudbeckia genus flowers are mainly yellow/orange, Echinacea genus flowers are mainly on the mauve-ish/lilac side of the colour temperature, but otherwise the shape can be similar (that of an upside-down shuttlecock with a conical display of reflexed ray florets and a central bulging dome of disc florets).
Flowers belonging to the
Helenium genus (such as Sneezeweed (Helenium autumnal) another garden plant which escapes into the wild, is also in the Asteraceae family) are also shaped like upside-down shuttlecocks, and moreover also have a yellow corolla, but smaller, like Bristly Coneflower. The leaves are similar too.
There are very many horticulturally generated variations of Bristly Coneflower, one with the common name of Black-Eyed-Susan (Rudbeckia hirta var. angustifolia).
Bristly Coneflower is a garden plant that can escape into the wild, usually onto rough ground and waste places. The specimens here are yet to escape...