All life on earth depends on plants. They feed us, they clothe us and more than 40% of our medicines are derived from them. Plants can modify weather systems, count and even communicate with each other. There are currently around 369,000 vascular plant species known to science, with around 2000 new plant species being described each year. However, 21% or 1 in 5 plant species is currently threatened with extinction.
Above: One of the last wild populations of Lachenalia viridiflora (CR) growing on a housing plot for sale in its West Coast home.
A recent study published in the journal Nature, Ecology and Evolution by researchers from Royal Botanic Gardens Kew and Stockholm University found that 571 plant species became extinct over the last 250 years, an extinction rate 500 times higher than would happen without human influence. This crisis if not addressed is something that will have a cascade effect, leading to extinctions of other life forms dependent on those species including animals, birds and pollinating insects.
Top: One of the last populations of Gladiolus jonquilliodorus on the Cape Peninsula. Above: Watsonia humilis (CR) at its last wild home on the Cape Flats, threatened by industrial development, illegal dumping and alien plant invasion.
One of main hotspots for plant extinctions was found to be South Africa’s Western Cape, second only to Hawaii. The Western Cape has lost a total of 37 plant species. However, these are just the plant extinctions that we know about, with the real numbers including lesser known taxa likely far higher.
Above: Haemanthus pumilio (EN), suffering from ongoing habitat loss from transformation for agriculture and wetland drainage.
Far more plant species are also threatened with extinction in the Cape Floristic Region, being pushed towards the brink by habitat loss from urban development, alien plant invasion, transformation for agriculture, overgrazing, water pollution and inappropriate fire regimes.
Top: One of the last Gladiolus aureus (CR) in the wild on the southern Cape Peninsula. Above: Moraea aristata (CR).
One such example is Gladiolus aureus, also known as the Golden Gladiolus. It is Critically Endangered in the wild and likely one of the most threatened species on the Cape Peninsula with less than 10 individuals remaining. Its habitat on the southern Peninsula has become highly degraded due to gravel quarrying and alien plant invasion and material for ex-situ conservation is currently held in only one botanical garden. This beautiful bulb is teetering on the brink. The Critically Endangered Protea odorata is in a similarly perilous state, with only three individuals remaining in the wild and efforts to cultivate it ex-situ having mixed results.
Above: Moraea melanops (EN), endemic to Critically Endangered Overberg Renosterveld and threatened by habitat loss from transformation for agriculture, overgrazing and runoff from agricultural chemicals.
So what can we do to turn the rising tide of losses? First we need to know as much as we can about our threatened species. Where do they grow and what habitats do they prefer? Where do they call home? Our partners at the Custodians of Rare and Endangered Wildflowers, supported by dedicated citizen science volunteers. Why not get involved? We also need to build capacity in the conservation sector, training the upcoming botanists and conservationists of the future so that they know, can identify and care about our flora.
Above: Restored population of Serruria furcellata (CR) following numbers of this species being reduced to one wild individual.
Once we know where our imperilled species are found, we need to conserve their home and habitats. We all have the power to lobby against inappropriate developments where we live as well as encouraging our local governments to prioritise clearing alien vegetation, both for conservation and for water security. Consider donating to South Africa’s conservation nonprofits who tirelessly work for our biodiversity. There are many local community groups volunteering for conservation action so why not join them? Every conservation action makes a difference.