KUNMING _ The Yunnan Tropical Plant Institute of the Chinese Academy of Sciences near Menglun, Mengla County in Xishuangbanna offers such a fascinating glimpse into the plant world that I have visited it twice.
My trips gave me the chance to gain a deeper insight into the distinctive charm of the institute's famous botanic garden. Established in 1959 by the late noted botanist Cai Xitao, it was the first tropical plant garden in the country. 
Nurturing about 3,000 species of tropical and subtropical plants including many rare and endangered species, it might also be one of the largest.
My first visit was in the dry season in Xishuangbanna, which usually extends from September to May.
Guided by a pretty local Dai girl, I made a one-hour trip to the core area of the garden which covers 1,000 hectares on an island shaped like a gourd. Under the scorching sunshine, the trip was exhausting.
I visited the plum garden and the arboretum. The plum garden, with a big pond embellished with beautiful lotuses, impressed me very much.
But there were too many tourists and guides strolling around, which dashed my hopes of communing with nature and savouring the charm of the beautiful garden.
Recently I made another trip to Mengla in the wet season. I decided to choose the guesthouse of the plant institute at the centre of the botanic garden for a one-night stay, giving me the chance to stroll around the garden after dusk and in the morning.
When I checked in at the guesthouse, the Science and Technology Exchange Centre of the institute, at 5:00 pm, it was raining heavily.
From the balcony of my second-floor room, I had a good view of the garden with its lushly growing plants.
After dinner, it stopped raining, so I decided to explore the garden by myself.
Unlike the first time, the garden was empty and tranquil. After the rain, the air was clear and refreshing. I could distinguish the flavours of the soil, the leaves of some trees, and flowers of plumeria obtusa.
Along the well-paved road, I walked to the plum garden. This time the trees looked different. With tall and straight trunks and tidy crowns, they looked really graceful. 
There is a lane stretching from the plum garden into the arboretum. Walking along it, I saw human-size vines, dark green ferns, various sago cycas trees and huge banyan trees with numerous air roots hanging down to the ground.
As the screen of darkness fell, fireflies floated out of the forest in their thousands, giving off flashes of light in the darkness.

Listening to the croaking of frogs in the forest and following the fireflies back to the guesthouse, I really felt I was communing with nature this time.
Next morning, I was woken by the whistles of peacocks and gibbons who had made their home in the garden. So I went for another walk and found the extraordinary beauty of various tropical and subtropical plants and flowers.
I saw rock-like Stephania epigaea, some species of the Palmae family with stalactite-like fruits hanging down from the trunk, weird-looking bamboos and colourful flowers.
The purple flowers of the passion fruit impressed me tremendously. With tender skin and a graceful shape, the flowers looked too beautiful to be real.
Photographer Yang Shizhong focused his lens on these unique plants and captured the distinctive charm of the botanic garden.

(Photos: top: Wax palm; next to top: Palm)
 

Mimosa

Scarlet banana