Cornus hongkongensis ssp. gigantea (Hand.-Mazz.) Q.Y.Xiang — Large-flower Hong Kong dogwood

Introduction

Large-flower Hong Kong dogwood is one of the most visually distinctive subspecies of Cornus hongkongensis. It occurs from central-southern China into northern Vietnam and is characterized by relatively large, thick, often obovate leaves together with larger inflorescences and broad, suborbicular involucral bracts (Xiang & Boufford 2005; Deasy et al. 2026).

Tree TSAR retains it at subspecies rank as part of the seven-lineage hongkongensis structure. Its conspicuous morphology makes it easier to recognize than some neighboring subspecies, but that morphological distinctness is still interpreted within the broader evergreen species complex rather than as sufficient evidence for species rank.

Horticultural and Agricultural Uses

Subsp. gigantea has clear ornamental potential because its larger leaves and broad bracts accentuate the display typical of C. hongkongensis. Wild-collected Vietnamese and Chinese accessions are present in specialist collections, where performance depends heavily on winter minimum temperatures and provenance (Deasy et al. 2026).

Named plants and accessions should retain collection data rather than being reduced to generic C. hongkongensis. That preserves both horticultural information about hardiness and taxonomic information about this geographically structured subspecies.

Conservation Concerns

There is no routine independent global conservation assessment for ssp. gigantea. The parent species is Least Concern, but this large-leaved southern lineage occupies only part of the species’ range.

Protection of humid subtropical and montane forest in southern China and northern Vietnam, together with provenance-rich ex situ collections, provides the most relevant conservation framework while the internal taxonomy of C. hongkongensis remains under active study.

Additional Information

Plants of the World Online search (opens in a new tab) — Kew search for the accepted subspecies.
Trees and Shrubs Online — Cornus hongkongensis (opens in a new tab) — Morphology, distribution, and cultivated accessions.

References and Further Reading

Deasy M, Crowley D, Aldridge J, Chişu R (2026) Cornus hongkongensis. Trees and Shrubs Online. https://www.treesandshrubsonline.org/articles/cornus/cornus-hongkongensis/ (opens in a new tab)

Royal Botanic Gardens, Kew (2026) Cornus hongkongensis ssp. gigantea (Hand.-Mazz.) Q.Y.Xiang. Plants of the World Online. https://powo.science.kew.org/results?q=Cornus%20hongkongensis%20subsp.%20gigantea (opens in a new tab)

Xiang Q-Y, Boufford DE (2005) Cornus. In: Wu ZY, Raven PH, Hong DY (eds) Flora of China, Vol. 14. Science Press, Beijing & Missouri Botanical Garden Press, St. Louis, pp. 206–221. https://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=108042 (opens in a new tab)