Common allergenic weeds

In general, weeds are a large group of plants that can grow in agricultural land and damage its quantity and quality by competing with the main plant. Therefore, it should be remembered that weeds are not useless or harmful in principle, and only because they grow unintentionally in an inappropriate place (such as agricultural and agricultural lands) are considered weeds from the point of view of agriculture.
Many of these weeds in Iran and the world are used for food, fodder, medicine and even ornamental purposes, so it might be better to call these plants weeds or unwanted plants. 
Weeds in Iran are very diverse and consist of different genera or families.
The pollen of some species of these plants are allergenic for humans and cause respiratory allergies.
The most important family of weeds in Iran that causes respiratory allergies (allergic rhinitis or asthma) is the Amarantaceae family. 

Persian name: saltwort,
scientific name: Salsola kali,   
common English name: common saltwort tumbleweed, Russian thistle   
. Different species of Salsula are scattered in the salty and desolate soils throughout the regions of Iran in summer and autumn.
The results of studies conducted by researchers in Iran show that among different plants, the pollen of Salsula species is one of the most common causes of respiratory allergies in Iran.
Various allergens from this plant such as Sal k 5, Sal k 4, Sal k 3, Sal k2, Sal k 1 have been identified as factors causing allergies in patients, among which Sal k 3 and Sal k 4 allergens have been identified by researchers in Iran. It has been identified for the first time in the world and registered in the World Bank of Allergens (WHO/IUIS). 
Pollination period: summer and early autumn

Persian name: Wild Rooster Crown
Scientific name: Amaranthus retroflexus   
Common English name: Redroot Pigweed   
Distribution: Amaranth genus is an important member of the Amaranthaceae family. Different species of this genus include wild cocklebur (A. retroflexus), white cocklebur (A. albus), weed cocklebur (A. graecizans) and green cocklebur (A. viridis) as weeds throughout Iran. They grow among agricultural lands, home gardens and gardens. According to the studies conducted in Iran, wild rooster pollen is considered one of the most allergenic plant pollens in the country, and a high percentage of people with seasonal allergies are sensitive to the pollen of this plant. 
Pollination period: summer and early autumn

Persian name: Selma Tere, Selmak
Scientific name: Chenopodium album   
Common English name: Goosefoot Lamb’s Quarter    
Distribution: The genus Chenopodium is an important member of the Amaranthaceae family. Different species of this plant, including C. album and C. murales, are generally grown as common weeds in agricultural lands, summer gardens, and home gardens throughout Iran. According to the studies conducted in Iran, salma tere pollen is one of the most allergenic plant pollens in the country, and a high percentage of people with seasonal allergies are allergic to this plant’s pollen.  
Pollination period: mid-summer to early autumn

Persian name: Kochia, ornamental broom, fiery bush, Qazvini broom
Scientific name: Bassia (Kochia) scoparia 
Common English name: Kochia Burningbush   
Distribution: Kochia is an important member of the Amaranthaceae family. This herb-shrub plant grows in different parts of Iran. Its common species 
is the ornamental broom (K. scoparia). This plant is green in color, which changes to red in autumn,
that’s why it is called fireweed or burningbush. 
According to the studies conducted in Iran, Kochia plant pollen is one of the most allergenic plant pollens in the country, and a
high percentage of people with seasonal allergies are sensitive to the pollen of this plant. 
Pollination period: from late spring and summer

Persian name: Dermene, Yushan, Terkh
Scientific name: Artemisia Spp   
Common English name: sagebrush Wormwood Mugwort   
Distribution: The genus Dermene has about 200 to 400 different species.
Wormwood is grown as a weed in many parts of Iran, and its common species are common wormwood (A. vulgaris) and wormwood (A. absinthium). According to the studies conducted in Iran, the pollen of Darmeneh plant is one of the allergenic plant pollens in the country, and a significant number of patients with seasonal allergies show sensitivity to the pollen of this plant. 
Pollination period: late summer to early fall

Persian name: Atriplex, salmaki, wild spinach, garden spinach, saltbush.
Scientific name: Atriplex Spp.   
Common English name: Orache Saltbush.   
Distribution: Atriplex or salmaki is a member of the Amaranthaceae family. It is a brackish plant and grows as a bush and sometimes a shrub in the desert and dry areas of Iran and is often planted for desertification.
Among the important species of this plant, we can mention A. lentiformis and A. leucoclada. 
According to the studies conducted in Iran, Atriplex plant pollen in dry areas is one of the allergenic plant pollens in the country.
Pollination period: summer to early autumn

Farsi name: Barhang, Barteng
Scientific name: Plantago spp   
Common English name: Fleawort Plantain   
Distribution: Different species of this plant include deer horn plantain (P. coronupus), spear head plantain (P. lanceolata) and egg plantain ( P. ovate) grow as a weed throughout Iran. According to the studies conducted in Iran, the pollen of Barhang plant species is 
one of the most important allergenic plant pollens in the country and is one of the main causes of allergic respiratory reactions in patients with seasonal allergies. Pollination period: mid-summer to early autumn

Persian name: Rumex, sorrel.
Scientific name: Rumex Spp.   
Common English name: Sorrel Duck.   
Distribution: This herbaceous plant is scattered in different parts of Iran. Common species of this plant are called sorrel (R. acetosella) and (R. crispus). 
Pollination period: late summer to early fall