A serendipitous discovery that led to identification of a new species of garden balsam in Kerala

Named Impatiens neo-uncinata, it bears morphological resemblances to Impatiens uncinata. However, it differs from the latter in the size of the flowers, basal and distal lobes, the dorsal petal and pollen

Impatiens neo-uncinata: a frontal view of the flower. Photo: Special Arrangement

A small plant with attractive milky-white flowers with red stripes discovered in the Western Ghats has now been identified as a rare, wild cousin of the popular garden balsam.

Researchers stumbled upon the herb during a floristic survey in the Agasthyamala biosphere reserve in Thiruvananthapuram district. They initially took it for Impatiens uncinata, a familiar species of the genus Impatiens, to which the garden balsams also belong.

But a closer look had prompted a detailed scientific study, which eventually resulted in the plant being labelled a new species of Impatiens (family Balsaminaceae).

S. Arya, assistant professor, PG and Research Department of Botany, PSG College of Arts and Science, Coimbatore, and V.S. Anil Kumar, Principal, Government College, Kasaragod, who were instrumental in its discovery and identification have named it Impatiens neo-uncinata.

Impatiens neo-uncinata | Photo Credit: Special arrangement

A paper written by them in the scientific journal Phytotaxa highlights the herb’s serendipitous discovery, its distinguishing characteristics and botanical importance. What makes Impatiens neo-uncinata special is that it has been reported only from a single locality at an elevation ranging from 1,000 to 1,250 m, and that too in a very few numbers.

Its remote location and low population have prompted the researchers to recommend that it be categorised as ‘Endangered’ using IUCN criteria.

On closer examination

The researchers had noticed the plant growing near streams and wetlands. “We initially took it for Impatiens unicinata, as there were morphological similarities. But the differences soon became evident when the plant was subjected to a closer examination,” Dr. Arya said.

“The new Impatiens population can be easily distinguished from the field by snowy white flowers with red stripes and comparatively large flowers. Detailed study of specimens showed that it was different from all other known species of Impatiens and consequently described here as a species new to science,” their paper in Phytotaxa said.

While Impatiens neo-uncinata bears morphological resemblances to Impatiens uncinata, it differs from the latter in the size of the flowers, basal and distal lobes, the dorsal petal and pollen. Size-wise, Impatiens neo-uncinata is a herb that grows up to 20 cm in height, with simple or branched stems. It grows in open areas of evergreen forests, particularly wetlands. Flowering and fruiting occurs from August to December.

The genus Impatiens has over 1000 species distributed in the tropics and sub-tropics. In India, the Himalayan and the north-eastern regions account for the highest diversity of Impatiens. The southern arm of the Western Ghats stands second in that respect.