When the County Recorder for Flowering Plants, Richard Aisbitt, visited the reserve in May, he found two different species of ragwort: common ragwort (Jacobaea vulgaris) and hoary ragwort (Jacobaea erucifolia).
In the language of flowers, hoary means covered with greyish hairs. The most obvious difference between these two species of ragwort is that whereas J.vulgaris has smooth, hairless stems and leaves, J.erucifolia is furred all over, but particulalrly on the underside of its leaves, with fine silvery hair.
Left: hoary ragwort; right: common ragwort.
Another difference is that common ragwort’s phyllaries, the adapted leaves that form a collar around the head of the flower, are tipped with black.
Left: common ragwort with black tipped phyllaries (near the cinnabar moth’s head). Right: hoary ragwort without black tips to its phyllaries.
Hoary ragwort contains the same toxins as common ragwort and can be just as damaging if it is eaten by livestock but it is not named in the 1959 Injurious Weeds Act. The Act applies only to common ragwort, which it names as Senecio jacobaea, the name it was known by before it was reclassified as Jacobaea vulgaris.
Next time you are in the reserve, see if you can find both species.
Southwick Country Park Nature Reserve 