Hi. Thanks for the query.. As per your complain black spots on tongue due to pollen allergy is not commonly seen and it can be more commonly seen in case of excessive intake of medication like antibiotics which can disrupt bacterial flora which can lead to fungal growth causing dark spots on tongue bismuth containing medicines,poor oral hygiene , dry mouth, long term intake of mouthwashes etc.. Condition is known as Black hairy tongue.. The black spots on tongue are commonly not an indication of anything serious but at times in very rare cases black spots on tongue can be caused due to malignancy of tongue.. In your case it can be associated with medication and improper oral hygiene so it is important for you to consult an oral physician and get evaluated and if medicines is the culprit consulting your physician and limiting the intake of medicines if possible can be done.. In case if it is not possible to reduce the medicine maintaining a good oral hygiene is to be done.. Do soda bicarb gargles.. Use a tongue cleaner to clean your tongue.. Gradually the black spots will start lightening.. Hope this helps.. Regards.. \