The revered science author died during treatment at Square Hospital around 4am on Friday. He was 88 years old.
"He was undergoing kidney dialysis. He had been suffering from a number of old age complications including lung infection," Mokarram Hossain, a nature writer, said quoting Sharma's family.
Sharma was put under intensive care at BIRDEM Hospital on Aug 30 with a severe bout of pneumonia. He was moved to Square Hospital after his health deteriorated on Thursday.
The author had somewhat recovered from the lung disease but succumbed to the ailment of his kidneys.
His body will be kept at the mortuary in Square Hospital, said wife Debi Sharma. The family will decide where to perform the last rites after their daughter Sreyashi Sharma's return from London, she said.
Before that, his body will be taken to Bangla Academy and Central Shaheed Minar for the people to pay tribute, she told reporters at their home at Dhaka's Siddheshwari.
"We were together for 55 years. I had become a part of all his thoughts. If I see him from a distance, and not as someone so close to me, I'll still say he lived a pure and saintly life."
Sharma was born in 1929 in Sylhet's Moulvibazar. His father Chandrakanda Sharma was a Kabiraj, or a practitioner of herbal medicine. It was his father's work that first introduced young Sharma to the world of nature.
He graduated with honours from Kolkata City College and got his masters from Dhaka University. He later taught botany at Karimganj College, BM College and Notre Dame College.
Sharma, who would dedicate his life to trees, went on to write more than a dozen books on the role of nature in human life. He received the Bangla Academy award in 1987 and the Ekushey Padak in 2015.
He had borrowed poetic expressions from Jibanananda Das, Jasimuddin and folklores such as the 'Maymensingh Gitika' to describe to his readers the many species of plants, flowers and fruits.
One of his famous books is 'Shyamoli Nishorgo' or 'Green Nature'.
Others include 'Samajtontre Bosobas' or 'Living in Socialism', 'Jiboner Shesh Nei' or 'No End To Life', 'Phoolgulo Jeno Kotha or 'Each Flower Is A Word' and 'Biggan Shikkha O Daiboddhotar Nirikh' or 'Science Education and Our Responsibilities'.
A leading advocate for nature-friendly cities, he worked tirelessly to nourish and create green patches within capital Dhaka.
"I will not be here one day, but these trees are here to stay. They'll provide the oxygen people need to breathe. There is no greater joy than this in life," he had famously told a programme.