Diversity and Its Implications of Curcuma Subgenus Hitcheniopsis (Zingiberaceae) with a New Record for Vietnam

Curcuma subgenus Hitcheniopsis (Zingiberaceae) comprises species valued for ornamental and medicinal uses in Southeast Asia, yet no comprehensive assessment has been conducted in Vietnam. This study provides the first integrative evaluation of Hitcheniopsis in Vietnam, combining species distribution modeling, field verification, herbarium examination, and Ornamental Value Index (OVI) analysis. Ten species were confirmed, including a new national record, C. rhabdota, with voucher specimens establishing its verified presence and extending the known range. Predicted habitat maps highlighted southern Vietnam and adjacent regions as suitable areas, guiding targeted surveys and conservation planning. Flowering occurred from April to September, with species occupying habitats from deciduous dipterocarp to dry evergreen forests. OVI analysis identified C. rhabdota, C. alismatifolia, and C. thorelii as species of high ornamental potential, supporting their use in horticultural breeding and potted ornamental production. Conservation assessments revealed that the endemic C. leonidii and C. pygmaea are Critically Endangered, C. rhabdota is Vulnerable, and C. sparganiifolia is Endangered, emphasizing the urgency of habitat protection and sustainable management. By linking verified diversity, phenology, ornamental value, and habitat modeling, this study establishes a novel, distribution-based framework for research, conservation, and sustainable use of Curcuma subgenus Hitcheniopsis in Vietnam and Southeast Asia.