Nettle (Urtica spp.)
Flowering: June - August
Nettles are herbaceous plants with typical stinging hairs containing formic acid. They have large elliptic and toothed leaves. Nettles are very common, they are found both in woods and in open lands (wastelands, gardens, parks, meadows or vegetable gardens). They are indicative of soil rich in nitrates. The main species found in Belgium are the greater nettle (Urtica dioica) and the lesser nettle (Urtica urens).
Pollen is released in large quantities in the air when the male flowers suddenly split open. But it does not seem to play an important role in allergy.
The Urticaceae family also includes the genus Parietaria (the pellitory). The pellitory pollen is highly allergenic in Mediterranean regions. In Belgium, this plant does very seldom grow here.