Euphorbia peplus L.
Petty spurge is a small, branched annual plentiful in gardens and arable fields. It is native and common throughout Britain. It appears indifferent to soil type and is recorded up to 1,500 ft.
The plant exudes a milky sap when damaged. The sap is a severe irritant if applied to the skin. The oil contained in the seeds is a drastic purgative. Petty spurge has caused poisoning among horses and cattle in Australia and sheep in New Zealand. The active principles in the seeds and foliage are not affected by drying.
Petty spurge flowers from April to November. The seed number per plant ranges from 260 to 1,200. Petty spurge may be found in fruit for 8 months of the year.
Seedlings emerge throughout the year except for the winter months but the main flush of emergence is from April to May. Most seed germinates within a year of shedding with just a few seedlings emerging in the following 5 years. Germination occurs at 5 to 10 mm depth in soil.
Seed recovered from house demolitions and archaeological digs and dated at 20, 25, 30 and 100 years old has been reported to germinate.
The seeds are dispersed explosively when ripe. Ants may aid with further dispersal.
Surface cultivations in spring and the tillage associated with root crops will keep petty spurge in check. It is important to prevent the weed seeding.
Updated October 2007.