How Did the Bauhinia, a Sterile Flower, Become the Symbol of Hong Kong?

When the the bauhinia flower flag rose over the handover ceremony on 1 July 1997, it was greeted by applause, marking Hong Kong’s transition into the postcolonial era. But some were nonplussed. The flower is a sterile hybrid, and Richard Saunders, author of Portraits of Trees of Hong Kong and Southern China, suggests that this means it is “arguably an inauspicious symbol for a city built on mixed Chinese and British heritage.”

There’s no denying its beauty. Scientifically known as Bauhinia blakeana, it is known for its profuse, large crimson-purple flowers with dark veins extending to the paler margins during its flowering period, which stretches anywhere from eight to ten months, from September to June. That makes the semi-evergreen tree an ideal ornamental plant in the urban landscape, especially during the gloomy winter months.

But the more you consider this plant, the more its choice as a symbol of Hong Kong seems unlikely. Although it is abundant in Hong Kong, its parents have no ties with the city at all. In 2005, Saunders traced the hybrid origin of Bauhinia blakeana by comparing its breeding system with those of other bauhinias, and confirmed that Bauhinia blakeana is the result of hybridisation between the largely sympatric species Bauhinia purpurea (commonly known as Purple Camel’s Foot) and Bauhinia variegata (commonly known as Camel’s Foot Tree) – both, according to the Hong Kong Herbarium, are exotic species, meaning they aren’t native to Hong Kong.

Bauhinia purpurea, characterised by its light pink petals and three stamens, traces its roots to southeastern Asia and is found throughout India, ascending to an altitude of 1,300 metres in the Himalayas. Similarly, Bauhinia variegata, with white or spotted petals and five stamens, originates from eastern Asia such as India and China. Both parent plants are capable of autogamy and xenogamy, which means that they can self-fertilise and be fertilised by pollen from a flower on a genetically different plant. The fruits of both plants take the form of elongated pods that burst open to release seeds when the pods ripen. As the parent plants overlap partially in their flowering periods and geographical habitats, and since they share the same range of bee and butterfly species as pollinators, it is feasible for Bauhinia purpurea and Bauhinia variegata to interbreed.

The result is the similar looking but completely sterile Bauhinia blakeana, which fails to set seeds and drop long pods like its parents do. Kwan Hoi-shan, a molecular biologist and a core member of the Bauhinia Genome project, says this isn’t uncommon in hybrids. “On the most basic level, the pollens of Bauhinia blakeana are degenerated and therefore cannot fertilise the ovules,” he says. As a result, the tree cannot produce mature fruits.

What this means is that Bauhinia blakeana can only be reproduced through horticultural practices such as grafting and rooting of cuttings. “Bauhinia blakeana shouldn’t even be called a species,” remarks Kwan. “It’s only an artificially maintained cultivar.” This means that each Bauhinia blakeana offspring in Hong Kong comes from a part of its parent, sharing the same genetic material, as well as that of its great-great-grandparent: the first Bauhinia blakeana in the city. The flowers you see around the city today are effectively clones of the same flowers seen by Hongkongers a century ago.

So how on earth did the daughter plant of non-indigenous parents become so common in Hong Kong? Kwan explains. “Back in the 1880s, when Hong Kong was still a British colony, French Catholic missionary and plant collector Jean-Marie Delavay chanced upon a Bauhinia blakeana plant close to a shore near by Pok Fu Lam while hiking,” he says. Delavay took a cutting and propagated it near Béthanie, the sanatorium run by the Paris Foreign Missions Society. Several years later, a cutting was offered to the Botanical Gardens.

It was there that the plant was properly documented and received its name Bauhinia blakeana, after 17th-century French-Swiss botanists Gaspar and Jean Bauhin, and Henry Blake, a keen botanist who later served as the governor of Hong Kong. As the average lifespan of Bauhinia blakeana is around 50 years, Saunders postulates that the hybridisation of the first locally discovered Bauhinia blakeana occurred between 120 and 170 years ago.

In the beginning, Bauhinia blakeana was a rare plant in Hong Kong. Yet after the tree in the Botanical Gardens withstood a typhoon in 1906, it was chosen to propagate new trees. Since 1914, it has been extensively planted as an ornamental across Hong Kong. Kwan estimates that there are tens of thousands of bauhinia trees around the city today, planted by a variety of government departments and private housing estates. Bauhinia blakeana has also become popular in other parts of the world such as Australia, California and Florida, where the trees thrive in full sun.

And of course, it also features prominently on Hong Kong’s flag and in its official crest. In 1987, the Basic Law Drafting Committee initiated the design competition for the new Special Administrative Region’s flag and emblem. Hon Bing-wah, a Bronze Bauhinia Star-winning artist and the headmaster of Hong Kong Chingying Institute of Visual Arts, was invited to be one of the judging panel members.

He still recalls it as a daunting process. Judges had to review 7,000 submissions from across the city, as well as from Hongkongers living overseas. He says the most difficult part was to look for something that best represented the abstract concept of “One Country Two Systems,” the governing philosophy that would allow Hong Kong to maintain its own legal, economic and educational systems for 50 years after the handover.

“We had to avoid certain shapes like the crescent which could be religiously sensitive,” says Hon. “A triangle enclosing a circle that suggests Lion Rock wasn’t lively enough. A sailboat couldn’t represent the whole of Hong Kong’s diverse communities. A dolphin wasn’t appropriate enough, while a dragon had varied resonances across cultures.” To add to the challenge, Hon and his team weren’t only looking for aesthetically pleasing designs, they had to opt out those that resembled the flags of other countries, which, if adopted, would have “subjugated Hong Kong to another round of ‘colonisation.’”

A blossoming bauhinia blakeana flower

They settled on a plant because nature was seen as “neutral.” The bauhinia had already been selected in 1965 as the city’s official flower, so it seemed like an obvious choice. But it was already used in the logo of the Urban Council—Hong Kong’s now-defunct city council—so Hon and his team had to give the design a twist. “Inspired by the auspicious spiral patterns found in Chinese paper cutting aesthetics, we arranged the bauhinia flower’s five petals like a windmill, incorporating movements to symbolise that Hong Kong is an energetic city which never stops progressing forward,” he says.

A star in each of the flower’s five petals is a direct reference to the five stars in the flag of the People’s Republic of China, which represent the four Marxist social classes under the rule of the Communist Party of China. Hon says it suggests Hongkongers’ embrace of their motherland, but others may see it simply as a reminder of China’s sovereignty over the territory.

After three years of selection, drafting, refining and consultation, the bauhinia emblem and flag designs were approved on 17 February 1990, ready to supplant the colonial Blue Ensign flag in 1997. The bauhinia also made its way onto Hong Kong’s coins, gradually replacing the Queen’s profile after 1993. Last year, the bauhinia was added to the enhanced watermarks of Hong Kong’s banknotes. It has also been the subject of artworks such as Ellen Pau’s “Emergence,” a sound art piece based on the DNA of Bauhinia blakeana, in her exhibition What About Home Affairs? that explored home and identity in February this year. All these examples testify Bauhinia blakeana’s unbreakable cultural and historical ties with the city.

Hon shrugs off the suggestion that there is a problem with the symbolism of a sterile flower representing Hong Kong. “Its sterility is never a problem,” he says. “If it cannot reproduce by pollination, it’ll thrive in another way.” It’s hard to ignore the beauty of tens of thousands of Bauhinia blakeana flowers blossoming during the coldest season, flourishing against all odds since the first rare individual was created, found and propagated.