Colney Heath is our only habitat for a very rare loosestrife, Lythrum hyssopyfolium, and also for Teesdalia nudicaulis, while there is but one other locality, a different one in each case, for four of its plants, Radiola linoides, centunculus minimus, Cuscuta epithymum, and Potamogeton acutifolius.
"Hertfordshire"
Herbert W Tompkins