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SA botanist discovers new species of iris in the Langeberg
Author: Wiida Fourie-Basson (Faculty of Science)
Published: 03/10/2022

​South African botanist Brian du Preez (29) has discovered a beautiful new species from the Iridaceae family high up in the Langeberg Mountains of the Western Cape, South Africa.

The name of the new species, Geissorhiza seracina (common name: Cherry Satin flower), is inspired by the deep cherry-pink colour of its petals – with seracus meaning cherry.

Brian says he was hiking a two-day long trail of 40 km with friend and mentor, Prof Peter Linder, on the Boosmansbos Wilderness trail to Grootberg, when he first found the plants in early December 2021.

“I took photos, but did not collect a specimen. It was only when I got back home and sent the photos to Dr John Manning, an expert on the Iris family, that we realised it is likely a new species," he explains. Dr John Manning works at the Compton Herbarium at the South African National Biodiversity Institute (SANBI).

A week later Brian went back up the mountain, hiking 34 kilometres in nine hours, to collect a herbarium specimen for examination and description of the morphology of the species. Some bulbs were collected for ex situ conservation in the Stellenbosch University Botanical Garden.

Together with another leading expert on the Iris family, Prof Peter Goldblatt, senior curator at the Missouri Botanical Gardens in St Louis in the USA, they recently published a description of the new species in the South African Journal of Botany.

Brian says it is one of his most exciting finds over the past ten years: “New Iridaceae species are rarely found, and I mostly find new legume species. It is not often that a new species turns out to be so beautiful".

Brian is currently pursuing a PhD-degree in botany at the University of Cape Town (UCT) under the supervision of Prof Muthama Muasya (UCT) and co-supervisor Prof Léanne Dreyer at Stellenbosch University (SU).  

With the latest discovery, the number of Geissorhiza species from South Africa now stands at 106, of which 24 were discovered since 1985. While the genus is taxonomically relatively well-understood, new species continue to be discovered in outlying or less accessible parts of the Greater Cape Floristic Region. 

For now, this beautiful species is known only from this one locality.

On the photos above, Brian du Preez and the newly-discovered Cherry Satin flower.