Why can flood-tolerant trees still stand tall and upright even when soaked in water?

Recently A Quan sent Squirrel Jun a photo of a spring outing at East Lake. The original intent was to show off the legendary Canon green (it is said that Canon cameras are unbeatable for photographing plants, with built-in Canon green), but Squirrel Jun was immediately captivated by the pond cypress trees in the background. So handsome! Standing in water yet with off-the-charts good looks, this tree absolutely had to be talked about, and so today's article came to be.

Wherever pond cypresses grow, they always unabashedly display the beauty of a primeval forest, constantly giving off the breath of moist pine resin. Standing among them feels like traveling back to Jurassic Park, for fear that a few Compsognathus might dart out from behind the trees and ambush you. By the way, pond cypresses are truly clever and highly capable; their shadows can be seen in swamps and wetlands. And they stand in the water all year round. Aren't you afraid of getting your "feet" swollen from soaking?

The pond cypress has its own wonders: missing someone is a breathing pain, and knee roots are breathing roots!

As for pond cypresses standing in water yet still full of green, this brings us to their special ability. Here we need to introduce a concept: knee-root plants. That's right, our pond cypress is just such a plant, and it is thanks to this special root system that it can reproduce and thrive. So-called knee roots are also a kind of breathing root, and in plant root classification they are also categorized as a type of modified root. Just like the breathing roots hanging down from the branches and trunks of banyan trees, only the pond cypress's knee roots grow in a different location. At present, plants with knee roots are not common; the most typical are pond cypress, bald cypress and water pine.

Knee roots are mostly seen on the roots of plants growing in swampy, damp zones. Because the environment is humid and air is pitifully scarce, the plants all fall into a panic of suffocation. The swamp water slowly flows past the roots, ceaselessly, which seems highly poetic, but for the plants it is a catastrophe: being submerged in water causes severe oxygen deficiency in the root system.

So knee-root plants, in order to avoid root suffocation and death, make a physiological stress response at the roots that are in full contact with water: the roots grow a batch of reverse cells so that the roots grow toward the water surface. Other tree species keep sending their roots deeper downward, while these strive to grow vertically upward until they emerge from the water and breathe fresh air.

Knee roots are very interesting, with shapes of every description: some look like bamboo shoots emerging from the soil, some like stalactites formed in karst caves, and some are so funny they look like Buddha's feet. Knee roots are mostly dark brown or brownish red, and their internal structure is very ingenious, with many well-developed air passages that transport air at all times, ensuring the plant's respiration and sustaining life, while also storing and transporting nutrients to ensure growth.

In these places, pond cypresses form scenery in all four seasons, but unfortunately you still don't know about them!

In warm spring at Dayan Pond, pond cypresses meet egrets

At Dayan Pond Reservoir in Chengchi Village, Ketan Town, Lujiang County, Anhui, more than 20,000 pond cypresses have been planted, restoring the water-forest ecological environment. Birds gather and frolic in the dense pond cypress groves, presenting a scene of ecological harmony. When pond cypresses sprout and egrets perch and breed, the scenery must be very beautiful. Next year I will definitely go again.

In summer roaming General Mountain, pond cypresses accompany the boardwalk

Nanjing General Mountain Scenic Area can proudly call itself "Nanjing's Jiuzhaigou" and "Jinling's first scenery." Its most unique view is the winding cypress bridge, with clear water and secluded woods. Tall and upright cypress trees rise one by one from the lake surface. The water is calm and clear as a mirror, and the cypress grove looks as if it were planted upside down in the heavenly court.

In cold autumn at Dalian Lake, pond cypresses play with light and shadow

Dalian Lake National Wetland Park is located near Xicen and Liantang in Qingpu. Pond cypresses stand in the water, water and trees blend, and the scenery of trees in the water and also on the bank catches the eye. The morning sunlight plays with light and shadow on the treetops, while slanting halos bounce off the water like a mirror.

In winter remembering Zhuzhen, pond cypresses play with ducks

Zhuzhen, a small town in the northwest of Luhe, Nanjing, borders Lai'an County, Anhui. It is a newly developed ten-thousand-mu forest park, where there are patches of peach trees, chestnuts and rapeseed; these sights are a matter for early spring each year. What must not be missed in winter is a stretch of pond cypresses at the reservoir of the Zhima Ridge scenic spot. Few people go there, patches of pond cypresses stand in the water, and ducks play in the water among the pond cypresses, offering a distinctive charm.

Squirrel Jun has recently been extremely envious of friends in the south. A few days ago A Quan said: "Squirrel Jun, quick, look at the moss all over the ground, and the little grass has sprouted too!" Then look at the green space downstairs from me, not a blade of grass. When spring is warm and flowers bloom and the south has already begun a new season in which peaches, apricots and plums are hopelessly hard to tell apart, the fallen petals of plum blossoms in the north have only just been swept away; when friends in the south begin wandering through seas of rapeseed flowers, the winter jasmine in the north has only just tied up its little braids; now tulips and hyacinths in the south are blooming in competition and drawing countless people to stop and admire, while in the north the mountain peaches have only just whitened the treetops.

Welcome to follow Plant Fan; Squirrel Jun is still here to enjoy nature and flowers and plants together with you!