Urticaceae
Parietaria*
This is a family of herbaceous plants and small bushes, that includes 45 genus and 1,000 species, and that usually grow in warm and tropical zones. In Spain, the most important genus from an allergological point of view stet Nettle (Urtica dioica) and Wall Pellitory (Parietaria judaica). Parietaria is so called because it grows in cracks or at the base of walls, stones, etc.
The pollen of Urticaceae is small (13-19 µm) spheroidal, spiculated, and has 3-5 pores. Pollens from Urtica and Parietaria are indistinguishable with an optical microscope.
The period of pollinisation is very long, from February to November. It is a very dominant pollen in all the Mediterranean area (Spain, Italy, France, Greece, Turkey, etc.), and it affects adults significantly more than children.
Parietaria judaica**
Parietaria*
Parietaria judaica**
Parietaria*
Optical microscope pollen view:**
Electronic microscope pollen view**
** Photos (c) Menarini, S.A. – Hospital Clínico de Barcelona