What kind of snow lotus did you buy? Wrong answer, you shouldn't buy any kind of snow lotus

Produced by: Science Popularization China

Author: Liao Xinfeng (Kunming Institute of Botany, Chinese Academy of Sciences)

Producer: China Science Expo

True and false snow lotus

Anyone who has read Jin Yong's martial arts novels probably knows about the Tianshan Snow Lotus (Saussurea involucrata), which only grows in the high altitude areas of the Tianshan Mountains in Xinjiang. It is as white as a lotus and is endowed with the power to bring the dead back to life in the martial arts world. Its magical effects in the novels have led many people to be very curious about it. In recent years, more and more people have begun to pick snow lotus, resulting in a sharp decline in the number of Tianshan Snow Lotus, which has now become an endangered plant.

Tianshan Snow Lotus is not as beautiful as everyone imagines. It is like a "big cabbage"

(Image source: inaturalist.org)

However, the sharp decline in the number of Tianshan snow lotus has not reduced people's curiosity and enthusiasm for snow lotus. People who travel to the southwest and the Qinghai-Tibet Plateau often encounter another kind of "snow lotus" that is said to be collected locally. The dried flowers of these "snow lotus" can be bought for only three or five yuan, which may make people confused: the legendary rare and life-saving magic medicine is sold at a cabbage price? In fact, this short, compact and hairy plant is likely to be a snow rabbit.

The snow lotus sold in Tibetan areas is basically wild-collected snow rabbits, not a legitimate commodity.

(Image source: provided by the author)

Snow lotus and snow rabbit both belong to the genus Saussurea, but they belong to two different subgenera. The difference between the two is also very significant. We can see the difference just from their plant morphology:

Snow lotus with bracts (above) and snow rabbit with small fruits (below), both types of plants are used as snow lotus

(Photo source: provided by Shanshan)

Snow lotus builds greenhouse, snow rabbit wears woolen pants

Many people find it difficult to distinguish between snow lotus and snow rabbit because both grow high in the mountains and have evolved unique bract structures to resist the cold.

The difference is that snow lotus has evolved a transparent bract structure . The inflorescence is hidden inside these bracts. The bracts themselves are translucent light yellow and contain pigments such as flavonoids, which can absorb destructive ultraviolet rays and protect the inflorescence inside. At the same time, the transparent structure can also transmit visible light and infrared light, which brings a significant warming effect to the inflorescence on sunny days, building a greenhouse on the mountains for snow lotus. Therefore, snow lotus is also called an alpine greenhouse plant.

Tangut Saussurea and alpine greenhouse plants warming structure diagram, bracts retained and not retained, the temperature changes are obvious after the sun comes out

(Image source: Reference 1)

Snow rabbits have evolved a wool structure. They have adopted another way to keep warm. The bracts that wrap the inflorescence are densely covered with wool, and the bracts wrap the entire plant tightly, which looks very warm, so they are called wool plants . The wool of snow rabbits has multiple functions. Not only does it keep warm, it can also reflect the strong ultraviolet rays in the mountains to prevent the snow rabbits from being burned, and it can also isolate the rain and dew from the mountains.

The wool structure of the jellyfish snow rabbit

(Image source: Reference 2)

Both types of "snow lotus" evolved from the same ancestor of the genus Saussurea. The bracts under the inflorescence may have simply served as a pollinator under the flower, or used to physically protect the entire inflorescence.

Saussurea starata

(Photo source: provided by Shanshan)

But the miracle of them is that this structure is not suitable for high-altitude cold environment, but under the background of high mountains, their bracts have been continuously evolved and gradually adapted to the high-altitude cold environment. However, the ideas of their bracts evolution are completely different: snow rabbits use the cotton wool of bracts to keep warm, crawling on the ground like a rabbit, curled up, and wrapped tightly; snow lotus uses bracts to build a small "greenhouse" for itself, so it can stand tall and slender even at high altitudes.

The wool structure of the jellyfish snow rabbit

(Photo source: provided by Shanshan)

The warming effect of the bracts allows them to stand tall.

(Photo source: provided by Shanshan)

What is even more incredible is that the bract structure of snow lotus actually evolved twice in parallel in the genus Saussurea, which means that the genus Saussurea may have failed countless times when it charged to higher mountains, but the method of using bracts to build a greenhouse allowed them to successfully land twice and eventually take root in the colder mountains.

For snow lotus, this is both good news and bad news. The good news is that the origin and evolution of snow lotus are more diverse than we thought, and each species represents a new evolutionary branch with unlimited potential; the bad news is that every time we lose a snow lotus on the mountains, we may lose not only a species, but also the evolutionary hope of a branch.

No matter what kind of snow lotus, it's better to stay in the mountains.

Whether it is the snow rabbit or the snow lotus, both plants are regarded as the mysterious Tianshan snow lotus, called "magic medicine", and are sought after by the public. On the one hand, it may be due to the exaggeration of the novel, and on the other hand, it may be because they are indeed used as folk medicine in the local area. Growing in high mountains and being difficult to domesticate and cultivate artificially also gives them a mysterious color.

But we should understand that this medicinal system is more of a habit and tradition, and it lags behind the development of contemporary medicine. It made sense in the past, but now we have better choices and we no longer lack the medicine with uncertain efficacy.

I believe that many people who buy the so-called snow lotus do not buy it for its medicinal effects. Many snow rabbits are bought as souvenirs. However, it is precisely this kind of harvesting and selling that has made the snow rabbits "dare not" grow taller, because once they grow taller, they will be conspicuous and will be harvested.

Research statistics show that although snow rabbits grow in the environment of high mountain scree, in areas where trade is serious and artificial picking is severe, the height of one type of snow rabbit - the cotton-headed snow rabbit - has declined significantly in the past hundred years, which means that the snow rabbits are getting shorter and shorter.

The height of the snow rabbit has been getting shorter over the past century. The vertical axis in the above and below figures is the height, and the horizontal axis is the time.

(Image source: Reference 3)

This change is not good for the snow rabbit itself. It needs to grow taller during the breeding season to attract more pollinators and complete the breeding process. But under the strong pressure of artificial selection, only those that grow short can be preserved. It is cruel to say that we humans only need a hundred years, or even a dozen years, to completely reverse the adaptive traits that a plant has evolved over millions or even tens of millions of years, and we don't have to take any responsibility.

Jellyfish snow rabbits, their habitat is originally an unreachable alpine drifting beach

(Photo source: provided by Shanshan)

Moreover, the process of picking snow rabbits is a devastating blow to the entire plant. Due to the harsh living environment of the gravel beach and the scarcity of nutrients, a snow rabbit needs to go through several years of dormancy and accumulation before it can emerge from the ground and bloom. The snow rabbit's flowers are hidden at the top of the typical fluffy leaves of the snow rabbit.

The bracts that are believed to have medicinal value are actually just the snow rabbit's adaptation to the high cold and strong ultraviolet environment. Its actual function is to allow the flowers hidden in the bracts and the subsequent seed development process to be in a suitable environment.

The flowers of the snow hare bloom at the top of the plant, attracting insects such as bumblebees for pollination.

(Photo source: provided by Shanshan)

The picking process does not distinguish the stage of reproduction of the snow rabbit. When the snow rabbit is picked, it may have just bloomed at the top and has no time to complete its reproduction and seed dispersal process. This is not important to the pickers, but it is a disaster for the snow rabbit. When the snow rabbit is uprooted, it has no organs for asexual reproduction in its habitat, and it has no second chance to return to its home.

Originally, the distribution of snow rabbits on the gravel beach was very sparse. Among the large number of seeds produced by snow rabbits, only a very small number had the opportunity to take root in the cracks of the rocks, and the subsequent growth process was very difficult and long. The wanton picking of humans, coupled with the high-altitude and cold environment, has caused much greater damage to these plants than in the plains.

Feathered snow rabbits grow in the cracks of the flowing gravel beach. After being harvested, there may be no chance for new feathered snow rabbits to grow in this area.

(Photo source: provided by Shanshan)

If this trend continues, maybe one day we won’t even see the little snow rabbits.

If the three-fingered snow rabbits that have already borne fruit are picked before they have finished spreading their seeds, their population will continue to decline, with no chance of survival.

(Photo source: provided by Shanshan)

Conclusion

Instead of taking the snow lotus away from their homeland for various gimmicks, it is a good idea to leave them all on the mountains to truly witness their miracles. We must know that it took them tens of millions of years and perhaps repeated failures to finally "climb" the mountains.

I hope that the snow lotus can still be preserved and bloom on the top of the mountain without having to carry the hope of helping humans come back to life, and it does not need to be taken back by us as a souvenir.

References:

[1]Nicholls, Henry. "Peak performer." New scientist 2939 (2013): 46-47. [2]Yang Y , Sun KH . The Ecological Significance of Pubescence in Saussurea medusa, a High-Elevation Himalayan "Woolly Plant"[J]. Arctic, Antarctic, and Alpine Research, 2008, 40(1):250-255.

[3] Law W, Salick J. Human-induced dwarfing of Himalayan snow lotus, Saussurea laniceps (Asteraceae)[J]. Proceedings of the National Academy of Sciences of the United States of America, 2005, 102(29):10218-10220.

[4] Zhang

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