Conservation of Britain’s biodiversity: Status of the rare English endemic <i>Hieracium mammidens</i> (Breast-toothed Hawkweed; Asteraceae)

Hieracium mammidens P.D.Sell, Breast-toothed Hawkweed, is a rare South-east England endemic. Common garden experiments showed that minor differences between populations at Waltham Park and Caesar’s Camp are not sufficient to recognise separate taxa. Excision of florets on five plants showed that seed is produced in similar amounts to control heads, thus demonstrating it is apomictic. A survey of all sites in 2024 found 162 plants in four populations; it was not refound in seven sites and is unconfirmed in another four sites. It is IUCN Threat Status ‘Endangered’.