Molecular biomarkers for grass pollen immunotherapy

Table 4 Grass pollen seasons timing and temporal overlap in Europe[32,55-59]

Regions	Grass pollen seasons timing and temporal overlap with other types of pollen
Northern, Western, Central and Eastern Europe	Grass flowering period starts at the beginning of May, finishes at the end of July Some grass plants are in flower even in August, even September (e.g., Poland) Air concentration of grass pollen usually peaks in June; pollination occurs about two-three weeks earlier at sea level and thereafter in the mountain regions
	Birch (Betula spp): Western Europe flowering period starts at the end of March, Central and eastern Europe from early April until May (2-8 wk), Northern Europe from late April to late May Ash tree (Fraxinus spp): In Central and South-Eastern Europe flowering period may partially overlap (April to May) with grass pollen season
	Asteraceae weeds, such as ragweed Ambrosia artemisiifolia var. elatior and mugwort Artemisia vulgaris, pollen season in Central and Eastern Europe may last from July to August-September
	Plantain Plantago spp: Pollen season from May to September in Eastern Europe
Mediterranean regions of Europe	Different grasses are flowering between April and August
	Olive (Olea europaea): Pollen season lasts from April to June, in regions of Greece, Spain, and southern Italy, overlapping grass pollen season
	Plane (Platanus spp): Pollen season partially overlapping with grass season, from April to May, in Southern France or Spain
	Pellitory Parietaria spp: Pollen has a long persistence in the atmosphere in the Mediterranean region, from April to October, even longer (perennial)
	Asteraceae weeds: Pollinate from August to October, similar to Chenopodiaceae/Amaranthaceae pollen from salt-tolerant weeds significant also for semi-arid areas
	Plantain Plantago lanceolata: Pollen season from April to July in Northern Spain
European islands with special climate characteristics	Iceland (cold-temperate oceanic country): Some grass species and sorrel (Rumex spp) flower in June, both with peaks in July; a second peak of grass-pollen is possible in some years in August; pollen season tails off in September; birch pollen season is short, starting in the second part of May until the beginning of June
	Canary Islands (Spanish archipelago with subtropical climate): Long-range transport of Poaceae and Amarantaceae/Chenopodiaceae pollen from southern Iberian Peninsula and Morocco (mixed with Oleaceae tree pollen) and from the African Saharan sector and Sahel