Are the plants on the Hong Kong regional flag called Bauhinia or Bauhinia?

As soon as it approaches July 1 every year, the Bauhinia will enter people's field of vision. Bauhinia × blakeana belongs to the genus Bauhinia of Leguminosae, the genus name is in memory of the Swiss-French botanist Bauhin brothers. The Chinese name "Bauhinia" describes its nearly round leaf apex bifid in the shape of sheep's hoof.

Bauhinia, alias Hong Kong orchid. Picture: Ianare / wikipedia

In China, there are many Bauhinia plants commonly used for ornamental cultivation, in addition to Bauhinia, B. purpurea and B. variegata are often used for street greening in the south. The names recorded in the Flora of China are different from those accepted by Hong Kong and Taiwan. for example, the "Bauhinia" in the population of Hong Kong corresponds to the "safflower Bauhinia" in the mainland. Hong Kong's "safflower Bauhinia" refers to the "Bauhinia" in the mainland.

In order to make it easier to understand, this article will introduce them according to the translated names of the Hong Kong version.

The trick to distinguish them: look at the flowers

Safflower Bauhinia (B. p.) is a tree or erect shrub, widely cultivated in subtropical areas of the world for ornamental use. The word "purpurea" means "purplish red", describing its more or less purplish red petals.

Safflower Bauhinia B. p. Slightly purplish red flowers (well, I know some people want to complain that it's too "slightly", but safflower Bauhinia is very light.) Picture: Dinesh Valke / flickr

Among the three kinds of Bauhinia, the color of safflower Bauhinia is the lightest, the petal stalk of the flower is obvious, and most of its stamens degenerate with only three fertile stamens (the other two are all five), so it is the easiest to distinguish from the three.

Palace powder Bauhinia B. v. And B. × b. The distinction between them is a little more troublesome.

Bauhinia generally does not bear fruit after anthesis, two of the five fertile stamens are obviously shorter, and the raceme is very short. But the reliability of these three features is limited, because: look at the fruit-you may also encounter a palace powder that has not yet entered the fruit stage, look at the stamens-the palace powder sometimes has two shorter stamens, look at the inflorescence-you really can't see it when it's not close enough.

Bauhinia, fertile stamens are three long and two short, and the whole inflorescence is compact. Picture: Pauk / flickr

However, the characteristics of petals are more obvious. The central adaxial petal of the palace powder Bauhinia is broad, with bright purple lines intermingled with yellowish green markings-a feature described by the addition of the word "variegata".

The palace powder Bauhinia, five fertile stamens are almost the same length, and the central adaxial petals are broad and striped. Picture: Krzysztof Ziarnek, Kenraiz / wiki commons

On the other hand, the central paraxial petals of Bauhinia Bauhinia are dark purplish red from the middle to the base, without markings (the word "blakeana" is added to commemorate the 12th Governor of Hong Kong, Sir Bree and his wife, who love plant research, regardless of their characteristics).

From left to right: general safflower Bauhinia B. P. with long petal handle and three fertile stamens; palace pink Bauhinia B. v. (generally light) with wide adaxial central valve and mottled veins; Bauhinia bauhinia B. × b., with two obviously short stamens in the middle and below the central adaxial valve. Picture: ArcherEmiya;australianseed.com;wikipedia

The design on the Hong Kong regional flag abstracts the five stamens and five petals of Bauhinia chinensis.

So, when will it bloom?

What? How can you tell when it doesn't blossom?

Why don't we wait for them to blossom...

A tree of bauhinia. Picture: J.M.Garg / wikipedia

Safflower Bauhinia B. p. The florescence is usually in autumn and winter, while the palace powder Bauhinia B. v. And B. × b. It may blossom at any time throughout the year, lasting for a very long time, and the heyday is generally concentrated in late winter and early spring. At that time, the scene of a tree with purple clouds covered with green clouds is very spectacular.

Especially if a row of bauhinia has blossomed. Picture: TreeWorld Wholesale / flickr

Why are they so alike?

In fact, the similarity of Bauhinia flowers is not very high, the flower type of the genus has a series of changes from radiation symmetry to bilateral symmetry, but also has a rich color. So why are these three kinds of Bauhinia so similar?

The leaves of Bauhinia and the leaves of Bauhinia are all very similar to those of Bauhinia. Picture: Mokkie / wiki commons

Because Bauhinia is a natural hybrid of Bauhinia Gongfen and Bauhinia safflower (B. v. × p. "Blakeana"). Because of reproductive isolation, the pollen abortion of Bauhinia, as a hybrid offspring, is unable to complete fertilization, which explains why it does not bear fruit after anthesis.

Beauty is beautiful, Bauhinia is "flowering but not real". Picture: Dinesh Valke / flickr

Safflower Bauhinia can bear fruit normally, and the shape of the fruit well maintains the characteristics of Leguminosae-pods, a type of fruit developed from a single carpel ovary (specifically belonging to the dehiscence of a dry fruit in a single fruit). All kinds of pods belong to this type of fruit, regardless of whether they are flat or bulging, whether they are segmented, how many beans are inside, and whether they are dehiscent after maturity.

This article is for the 2015 year of species Calendar, from the author of species Calendar @ ArcherEmiya.

All the fun is here.

Let me show you more about plants.

Calendar Niang today's avatar

Leguminous soybean