Mid-summer marks that time of the year again when the dangerously beautiful Formosa lily (Lilium formosanum) is in full display. Eye-catching as they may be, these perennial lilies are no saints, at least not here in South Africa where they have established themselves to the effect of being classified as a Category 1b invasive alien species (IAS). As such, it is illegal to propagate, plant or trade these lilies and wherever possible, they must be removed and destroyed in the proper manner.

Formosa lilies, beautiful yet highly invasive.

The lily has a showy white trumpet-shaped flower, decorated with alluring maroon stripes along the outside of the tube, that sit atop an erect stem. Moreover, they exude a delightful fragrance. It then comes as no surprize that these lilies have made their way from Taiwan (formerly the island of Formosa) to gardens in various countries across the globe.

But why have they been listed as invasive here and how are they a threat to a critically endangered grassland? Species are dubbed “invasive aliens” when they have been introduced, or have spread, beyond their natural range to the point where they threaten local biodiversity. A plant species’ invasive potential hinges on the fact that it lacks natural enemies and that it is easily able to out-compete indigenous plants for resources such as space, light, water and nutrients. In the long run, IAS’s disrupt the functioning of ecosystems and can be extremely costly to control or remove.

Seed pods before becoming completely dried. A single pod disperses vast amounts of seeds.

The Limpopo Province’s only critically endangered vegetation type, i.e. Woodbush Granite Grassland (WGG), has not been spared the Formosa lily invasion. Though the WGG ecosystem is an acclaimed hub of biological diversity, it is an ecosystem at risk of irreversible transformation with an estimated less than 6% of its original extent remaining. The conservation of WGG lies at the heart of the Friends of the Haenertsburg Grasslands (FroHG). In this very special grassland, the crucial control of IAS is implemented by Jessica Letsoalo’s Hlole Project, which is funded by the National Department of Environmental Affairs.

Members of the Hlole Project working hard to clear an area of invasives.

As a registered NPO, FroHG relies entirely on donations and appreciates any contributions. Visit www.frohg.org for more information.