Hullett discovered the plant Bauhinia hullettii (a synonym for Bauhinia ferruginea var. ferruginea) on Mount Ophir in Malaysia. The Bauhinia, an orchid-like plant with delicate flowers, became his passion. A variant of Bauhinia, known as Bauhinia blakeana, has been adopted by Hong Kong for its national flag. Bauhinia blakeana was adopted as the floral emblem of Hong Kong by the Urban Council in 1965. Since 1997 the flower appears on Hong Kong's coat of arm, its flag and its coins. A statue of the flower was presented to the people of Hong Kong by the People's Republic of China and is today to be found in Golden Bauhinia Square in Hong Kong. Although the flowers are bright pinkish purple in colour, they are depicted in white on the flag of Hong Kong. The origins of Bauhinia blakeana are not known. The plant itself is a cross of two variants. It is sterile and the trees we see today all over Hong Kong came from one plant discovered in Hong Kong in the 1880s, possibly the result of one of Hullett's many experiments in propagation.