Impatiens L. (Balsaminaceae) includes ca. 900 species widely distributed in tropical, subtropical and temperate areas (Chen et al. 2007). The Impatiens species are widely used as ornamental plants in botanical gardens. The Indochina region (incl. Vietnam, Laos, and Cambodia) should be an area of diversity for Impatiens in Southeast Asia, but many species are still undescribed, since the family has attracted little attention during the more than seventy years since it was last inventoried by French botanists. So far, there are ca. 45 Impatiens species recorded for the flora of Vietnam.
While investigating the diversity of the flora of Vietnam, botanists from Vietnam National Museum of Nature, Vietnam National University of Forestry, Thu Dau Mot University collected an unfamiliar specimen of Impatiens that is not regarded to any previously known Impatiens species in Vietnam, but its morphological characters completely match with those of Impatiens siculifer – a previously known species from China and India. Therefore, we here report Impatiens siculifer as a new record for the flora of Vietnam. A full description together with information on habitat, ecology and distribution is presented.
Impatiens siculifer is similar to I. stenantha Hook. f. in having an erect, glabrous stem, elliptic-lanceolate leaf blade, coarsely crenate leaf margin, 3–5 flowered axillary inflorescences, yellow flowers, and long curved spur, but distinct from the latter in having persistent floral bracts, narrowly oblong lateral sepals, and a thickened abaxial mid-vein on the upper petal.
The results were published on Acta Phytotaxa Geobotany 70 (1): 63–66 (2019), doi: 10.18942/apg.201817.
Figure: Morphological characters of Impatiens siculifer
Do Van Truong, PhD
Vietnam National Museum of Nature, VAST