Ashes particularly rich in potash are those of burning nettles, wormwood (Artemisia absinthium), tansy (Tanacetum vulgare), fumitory (Fumaria officinalis), and tobacco.
Specific action has also been undertaken by English Nature to survey and promote the importance of purple ramping fumitory among arable farmers and landowners.
Climbing Fumitory (Adlumia) - Climbing biennial plants.
Bracted Fumitory (Corydalis Bracteata) - A distinct kind, with yellow flowers.
Yellow Fumitory (Corydalis Lutea) - Graceful masses of delicate pale green leaves dotted with spurred yellow flowers.