On the day of Hong Kong's return, let's take a look at Hong Kong's district flowers

In a blink of an eye, half of 2022 has passed. Turning over the calendar, it is July 1st of another year. Today is the 101st anniversary of the founding of the Communist Party of China and the 25th anniversary of Hong Kong's return to the motherland.

When talking about Hong Kong, China, the "Bauhinia" will naturally come to mind. Feng Menglong of the Ming Dynasty used the story of Bauhinia to illustrate brotherhood. In many cities from the south of the Yangtze River to the north, Bauhinia is also a common urban greening plant.

Bauhinia rubra | Michelia

This Bauhinia is not that Bauhinia

However, if you have observed the Bauhinia flowers on the roadside in the north, you will find that... Hey, this is not what we said! How come these small flowers that are densely blooming on the tree trunks are nothing like the five large petals on the Hong Kong flag? In the Flora of China, the "Bauhinia" column reads: "The flowers are purple-red or pink, 2-10 or more in bunches, growing on old branches and trunks, especially on the trunks." In other words, it is the authentic Bauhinia in the north. So, what is the regional flower of the Hong Kong Special Administrative Region?

The real Cercis chinensis, with flowers densely blooming on the trunk | Michelia

It turns out that the "Bauhinia" of the Hong Kong Special Administrative Region has a different flower. In the Flora of China, the name of this plant is Bauhinia rubra, while in Hong Kong, China, people like to call it "Bauhinia bracteatum". Many people may not be able to tell the difference, and since then, these two plants have been confused.

Bauhinia blakeana belongs to the genus Bauhinia of the Fabaceae family. "Sheep's hoof" refers to the shape of the leaves. Their leaves are round and split into two at the tip, like sheep's hooves, hence the name Bauhinia - although I personally think it looks more like apples. When I was a child, I often used its leaves to fold rabbits to play with.

The leaves of the genus Bauhinia are generally in the shape of a sheep's hoof | Michelia

One of the important reasons why Bauhinia rubra was chosen as the district flower is that its type specimen was collected from Hong Kong. The so-called type specimen is the specimen used as evidence when botanists discover a new species. In other words, Bauhinia rubra was first discovered in Hong Kong, China.

Statue at Golden Bauhinia Square, Hong Kong | Michelia

The collector of this type specimen is Stephen Troyte Dunn, a British botanist who worked in Hong Kong, China in the early 20th century. According to Dunn's records, Bauhinia scabra was first discovered by several priests near a dilapidated house by the sea, and then some were propagated by cuttings. He himself collected this specimen in the Hong Kong Botanical Garden in 1905.

The holotype of Bauhinia blakeana | Hong Kong Herbarium

Dunn determined that this was a new species of the genus Bauhinia and named it blakeana in the formal paper he published, in honor of the 12th British Governor of Hong Kong, Henry Arthur Blake and his wife, who were said to be fond of plants and who were Dunn's early leaders. But I guess if Dunn knew the true origin of Bauhinia, he might not have used the leader's name...

Follow dad or mom?

When Dunn published his article, he had not seen the fruit of this plant. More than a hundred years have passed, and with its beautiful appearance, Bauhinia serrata has already been planted all over China, but almost no one has ever seen its fruit. So the question is, if Bauhinia serrata cannot produce seeds that can germinate, how did the first tree come about?

Bauhinia rubrum | Wikimedia Commons

It turns out that Bauhinia variegate is not native to the wild, but is a hybrid of two species of the genus Bauhinia - its parents are Bauhinia variegate and Bauhinia purpurea. It is said that the love between seabirds and fish is just an accident, but the accident of Bauhinia variegate and Bauhinia purpurea crossing species can actually leave a child. Although it is difficult to bear fruit, it has been planted all over the world through cutting propagation, which can be regarded as a successful result.

Bauhinia odorata (top) and Bauhinia odorata (bottom) | Michelia

In many cities in southern China, these three species of Bauhinia are important greening trees, and can be seen everywhere, on roadsides and in parks. At my alma mater, South China Agricultural University, any student who has taken a course in dendrology can tell the three species apart at a glance, even if they only look at their leaves.

The leaves of Bauhinia are split close to the middle | Michelia

The leaves of Bauhinia scabra are relatively large, with a diameter of nearly 15cm, and the tip can crack to nearly the middle. The leaves of Bauhinia scabra are small, generally not exceeding 10cm in diameter, and are relatively shy, with the tip generally only cracking to 1/4~1/3. As the child of the two, Bauhinia scabra takes the shape of its father and the size of its mother - its leaves can reach a diameter of 15cm, and the cracks are only to 1/4~1/3.

The degree of leaf cracking of Bauhinia odorata (above) and Bauhinia odorata (below) is similar | Michelia

When they bloom, it is easier to distinguish them. Although Bauhinia is the longest, its petals are the most slender of the three, usually pink or nearly white. It has only 3 stamens and blooms in autumn and winter, with leaves when it blooms. The petals of Bauhinia are broadly oval, pink to light purple, with dark spots on one of them; it has 5 stamens, blooms in early spring, and leaves fall when it blooms.

Bauhinia has narrow petals and 3 stamens (above); Bauhinia has wider petals and 5 stamens (below) | Michelia

The petal shape of Bauhinia rubra is between the two, wider than Bauhinia rubra and longer than Bauhinia rubra. The number of stamens is the same as that of Bauhinia rubra, which is also 5. Bauhinia rubra is thick-skinned and often blooms all year round, blooming most vigorously in winter. In addition, as mentioned above, Bauhinia rubra usually does not bear fruit, so when you see a Bauhinia tree full of pods, it goes without saying which one to pass first.

The petal shape of Bauhinia rubra is between the two, with 5 stamens | Michelia

In December, the red-flowered Bauhinia tree is in full bloom, and the Bauhinia next to it has already hung fruit pods | Michelia

Look, it's pretty easy to tell the three types of Bauhinia apart, right? Have you learned it? But to be honest, the name "Bauhinia" is still a little hard to pronounce. Perhaps because of this, many campuses and scenic spots that are full of Bauhinia prefer to use the name "Bauhinia" to promote it.

After the red Bauhinia blooms, the petals often fall all over the ground, which is a beautiful sight in winter in South China | Michelia

Whatever, the name is just a code name after all. As long as the Latin name is correct, everything is fine. So, let's just call it Bauhinia, and have fun admiring the flowers.

This article comes from the Species Calendar, welcome to forward

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