Lemna Minor also known as Duckweed is an aquatic plant. Leaves of this remedy are used homeopathically. This is an excellent remedy for blocked nose and nasal inflammation.
Lemna Minor is used curatively for-

Nose

Loss of smell
Putrid smell
Abundant discharge which is mixed with mucus and pus
Post nasal discharge in cold
Nasal polyps which causes nasal obstruction

Mouth

Putrid taste in mouth on waking up in the morning
Dryness of throat

Abdomen

Diarrohea
All complaints are worse in cold damp weather especially heavy rains

Dose – As prescribed by physician. Can be taken along with other allopathic medicines.

Side effects- None

Precautions

Maintain half an hour gap between food/drink/any other medicines and homeopathic medicine.
Avoid any strong smell in the mouth while taking medicine e.g. camphor, garlic, onion, coffee, hing.

Use under medical supervision.