I see the "Bawanghua" again! Why can't I get rid of this guy?

Recently, news of the "encirclement and suppression" of Canada goldenrod has been reported again in various places. When the autumn and winter seasons change, the fruits of this flower enter the ripening period, and countless seeds are scattered by the wind. If timely action is not taken, the difficulty of subsequent removal will increase sharply.

Canada goldenrod

Image source: www.minnesotawildflowers.info

Canada goldenrod is a frequent visitor to the "blacklist" of the flower world, as no grass grows wherever it goes. It poses a major threat to the balance of native ecosystems and seriously infringes on biodiversity, hence the notoriety of "plant killer" and "flower queen".

What is particularly troublesome is that its reproductive capacity is amazing, comparable to that of cockroaches, and its vitality is extremely tenacious, making it impossible to eliminate or eradicate it!

0 1 Goldenrod is gorgeous and practical

In the huge family of Asteraceae, in addition to the enchanting and colorful ornamental chrysanthemums, there is also a unique type of wild flowers. They are single upright plants, tall and slender, with clusters of yellow flowers on their branches. Because of their simple and distinct characteristics, they are hastily but vividly called "Goldenrod".

Goldenrod is a perennial herb that can grow up to 2 meters tall with an upright stem and few branches. Its flowers are small and bright, arranged in a cone-shaped inflorescence, like a carefully woven work of art. The flower language of this plant is "flowers bloom and wealth comes", implying prosperity and abundance. Whenever it blooms, it seems to convey happiness and good wishes to the world.

Goldenrod not only has a high ornamental value, but also contains rich medicinal value. In terms of ornamental value, it is often used in the layout of courtyards and flower beds to add natural beauty. It is also a popular standard flower in the fresh cut flower market, and it complements flowers such as baby's breath, each with its own characteristics.

In terms of medicinal use, its inflorescences and leaves are rich in various trace elements that are beneficial to the human body. They have many functions such as detoxification, swelling reduction, and treatment of rheumatoid arthritis, and have attracted much attention in the medical community.

As an important genus in the Asteraceae family, Solidago has a wide variety of plants, totaling more than 100 species, most of which are distributed in the Americas, with a few scattered in Europe and Asia.

In my country, there are currently six known species of Solidago, three of which are native species, including Solidago, Solidago obtuse and Solidago dasyphylla; the other three are introduced species, namely Solidago canadensis, Solidago talla and Solidago rugosa.

Among them, Canada goldenrod has become the most well-known one with its unique charm and wide distribution.

0 2 “Bawanghua” has extraordinary advantages

Canada goldenrod first thrived in southern Canada, hence its name; later, its footprints expanded to the United States, Mexico, Japan and other countries. In 1935, during the Japanese invasion of China, this species was introduced to Taipei, my country, and gradually spread to Jiangsu, Shanghai and other places. Since the 1980s, it has rapidly expanded throughout my country and has become a very harmful invasive species. It has been listed in the first level of the "List of Alien Invasive Species in China (Second Batch)" and is classified as a malignant invasion.

The main harm of Canada goldenrod is the serious damage to the local ecological balance and biodiversity. It has extraordinary advantages in reproduction, environmental adaptability and competition for living space.

Its reproductive capacity is amazing. Canada goldenrod not only reproduces sexually through flower seeds, but also relies on underground rhizomes to achieve asexual reproduction , quickly giving birth to a large number of new plants. The underground rhizomes reproduce rapidly, and even some of the rhizomes can survive, truly achieving the goal of "if you don't remove the roots, the grass will grow again in the spring breeze."

In addition, it has a huge number of seeds, with a single plant producing more than 20,000 seeds; the seeds are light and have pappus, making them easy to be blown away by the wind or attached to other objects, and have a strong ability to spread.

In terms of environmental adaptability, Canada goldenrod is not afraid of severe cold and remains lush when other autumn weeds wither or stop growing.

The most troublesome thing is its ability to occupy living space. The roots of Canada goldenrod secrete allelopathic substances, which interfere with or inhibit the growth of surrounding plants, causing the number of adjacent plants to decrease or even become extinct, truly achieving the goal of "no grass grows wherever it goes." Canada goldenrod has become a veritable "dominant flower."

0 3 Differentiate from flowers and leaves

The nine sons of a dragon have their own merits, and the same is true in the plant world. Although Canada goldenrod and China's native goldenrod belong to the same goldenrod family, they show distinct differences in inflorescence structure and leaf morphology.

Looking closely at the inflorescence, Canada solidago stands proudly in a panicle on one side of the branch (often leaning upwards), and most of its inflorescence branches are elegantly curved; the native solidago surrounds the branch and blooms evenly in the form of a raceme, with the inflorescence branches standing upright, showing a completely different appearance.

The difference between Canada goldenrod (left) and Solidago in inflorescence

As for the leaves, the two are even more different. The leaves of Canada goldenrod are like sharp sword blades, lanceolate or linear lanceolate, with veins extending parallel to the leaf axis and smooth lines; while the leaves of the native goldenrod are oval, with veins and the middle part of the leaf showing a feather-like distribution, adding a bit of delicacy and softness.

The difference in leaf shape between Canada goldenrod (left) and goldenrod

In addition, the height and volume of the upright stems and the complexity of the branches on the top of the flowers also have their own characteristics. In short, Canada goldenrod is famous for its thick upright stems and luxuriant branches on the top; while the native goldenrod, although also belonging to the goldenrod, shows a simpler and more rustic style in these aspects. All these things show the wonder and diversity of nature's creation.

0 4 The oriole is not a "dominant flower"

Flower lovers are familiar with the "Yellow Oriole" fresh cut flower in flower shops. Yellow Oriole, also known as the lucky grass, quickly became popular at the beginning of this century with its small and exquisite yellow flowers and lively appearance. It once surpassed Gypsophila paniculata and became the top flower in the flower market.

However, due to its striking resemblance to Canada goldenrod, the yellow warbler was once mistakenly considered an alien invasive species, causing people to worry that keeping it would violate the relevant provisions of the "List of Alien Invasive Species in China". This misunderstanding undoubtedly cast a shadow on the yellow warbler.

Yellow oriole sold in the flower shop

In fact, the yellow warbler is just an artificially cultivated variety of Canada solidago (or tall solidago), mainly planted in Yunnan, Guangdong and other places. After in-depth research, experts found that the yellow warbler not only lacks sexual reproduction ability, but also does not release allelopathic substances. The ability of its seeds to spread under artificial cultivation conditions is also quite limited, and it has nothing to do with the "king flower".

Therefore, it is not appropriate to simply regard the yellow warbler as another name for Canada goldenrod. From a professional perspective, the yellow warbler can at best be called a "variant Canada goldenrod." This clarification undoubtedly justifies the name of the yellow warbler and relieves unnecessary worries for flower lovers who love it.

References

"The impact of the invasive species Solidago canadensis on soil properties", Lu Jianzhong, Qiu Wei, etc., Biodiversity, 2005

"Research Progress on Canada Solidago", Yin Liping, Tan Yongbin, Shen Guohui, Yao Hongmei, Weed Science, 2004

"Biological Characteristics of Canada Solidago and Its Control Measures", author Li Mingtao, "Agricultural Disaster Research", Issue 3, 2013

Author: Wei Deyong

Member of Guangdong Shenzhen Writers Association

Editor: Dong Xiaoxian

Reviewer: Liu Kun and Li Peiyuan