Hong Kong Orchid Tree

Scientific Name : Bauhinia × blakeana Dunn
Common Name : Hong Kong Orchid Tree
Chinese Name : 洋紫荊, 紅花羊蹄甲, 豔紫荊
Family : CAESALPINIACEAE
Local distribution status : Native species

Anecdotes on plants

Origins	Hong Kong. First discovered in Pok Fu Lam in 1880s by the fathers of the Mission Etrangérès in Hong Kong, who had cut the branches for transplanting.
Applications	The flowers of Hong Kong Orchid Tree are large and eye-catching, which contribute to its popularity as a horticultural tree species. However, the species is infertile, and can only be propagated through artificial means such as grafting.
Relationship with Hong Kong	Citizens in Hong Kong are familiar with Bauhinia x blakeana Dunn, since it is the city flower of Hong Kong. It has also been adopted as the symbol featured on the Flag and Regional Emblem of Hong Kong Special Administrative Region.
Meaning of name	The species epithet “blakeana” in its scientific name was adopted for memorializing the 12th Governor of Hong Kong, Sir Henry Arthur Blake and his wife for their contribution on botanical research and the Hong Kong Botanic Gardens (the current Hong Kong Zoological and Botanical Gardens). Hong Kong Orchid Tree was identified as a new species and named by the then Superintendent of the Botanical and Forestry Department S. T. Dunn in 1908.
Parents of Hong Kong Orchid Tree	According to modern molecular studies, the species is a crossed hybrid. Its female parent is the Purple Camel's Foot (Bauhinia purpurea L.) while the Camel's Foot Tree (Bauhinia variegata L.) is the paternal plant.

Traits for identification

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Remarks

Scientific name above is based on Hong Kong Herbarium website : https://www.herbarium.gov.hk/en/hk-plant-database/plant-detail/index.html?pType=species&oID=8328

Scientific names from other databases
― Flora of China : Livistona chinensis Bauhinia × blakeana Dunn
― Plants of the World Online : Bauhinia × blakeana Dunn

Reference

• Agriculture, Fisheries and Conservation Department (AFCD). (2018). A Photographic Guide to Common Urban Trees of Hong Kong. 3^rd edition. Agriculture, Fisheries and Conservation Department, Hong Kong. ISBN: 978-988-12021-3-0.
• eFloras. (2008). Bauhinia × blakeana Dunn. Flora of China. [Online Edition]. Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA. Retrieved 3^rd March 2020, from: http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=250094082
• Hong Kong Herbarium, Agriculture, Fisheries and Conservation Department & South China Botanical Garden, Chinese Academy of Sciences. (2007-2011). Bauhinia × blakeana Dunn洋紫荊. Flora of Hong Kong. [Online Edition]. Retrieved 3^rd March 2020, from: https://www.herbarium.gov.hk/FloraOfHK/Species/8328/8328_S_E.pdf
• Jim, C. Y. (2006). Bauhinia Trees: from Obscurity to Celebrity. Chan, W. C. [Chinese Translation]. Cosmos Bookstore Ltd. & Friends of the Country Parks, Hong Kong. ISBN 988-211-328-1.
• Lai, P. (2016). A Historical Account of Our City Flower, Bauhinia x blakeana. Special Topics. Knowledge Sharing. Knowledge Database. Greening, Landscape and Tree Management Section, Development Bureau. Retrieved 14^th December 2020, from: https://www.greening.gov.hk/en/knowledge_database/special_topics.html#paragraph1
• Lau, C. P. Y., Ramsden, L. & Saunders, R. M. K. (2005). Hybrid origin of "Bauhinia blakeana" (Leguminosae: Caesalpinioideae), inferred using morphological, reproductive, and molecular data. American Journal of Botany, 92(3), 525-33. [doi: 10.3732/ajb.92.3.525]. Retrieved 3^rd March 2020, from: https://www.researchgate.net/publication/51201005_Hybrid_origin_of_Bauhinia_blakeana_Leguminosae_Caesalpinioideae_inferred_using_morphological_reproductive_and_molecular_data
• Mak, C. Y., Cheung, K. S., Yip, P. Y. & Kwan, H. S. (2008). Molecular Evidence for the Hybrid Origin of Bauhinia blakeana (Caesalpinioideae). Journal of Integrative Plant Biology, 50(1), 111-118. Retrieved 3^rd March 2020, from: http://www.jipb.net/EN/10.1111/j.1744-7909.2007.00591.x
• Shiu-Ying Hu Herbarium. (2020). Bauhinia × blakeana Dunn 洋紫荊. Factsheet. Taxonomical Archive System. Wu Jieh Yee Charitable Foundation Native Plant Resources and Database in Hong Kong. Retrieved from 3^rd March 2020, from: https://syhuherbarium.sls.cuhk.edu.hk/collections/factsheet/bauhinia-x-blakeana/
• 中國科學院仙湖植物園。（2010）。《深圳植物誌》（第2卷）。北京 : 中國林業出版社。國際標準書號 : 978-7-5038-5884-0。
• 中國科學院植物誌編輯委員會。（1959-2004）。〈紅花羊蹄甲Bauhinia blakeana Dunn〉。《中國植物誌》。[網上版本]。於2020年3月3日擷取自 : http://www.iplant.cn/info/Bauhinia%20blakeana?t=z
• 中國科學院華南植物園。（2003）。《廣東植物誌》（第5卷）。廣州 : 廣東科技出版社。國際標準書號 : 978-7-5359-3322-X。
• 包滿珠。（2011）。《花卉學》。北京 : 中國農業出版社。1998年第1版，2011年第3版。國際標準書號 : 978-7-109-16416-1。
• 電子版香港法例。（2017）。〈文件 A602 《區旗及區徽條例》〉。《電子版香港法例》。於2020年12月14日擷取自 : https://www.elegislation.gov.hk/hk/a602!en-zh-Hant-HK?INDEX_CS=N