Stellenbosch University Botanical Garden, South Africa

Common name: Waterklawer, Watersuring

Family: Oxalidaceae (Wood-sorrel)

Distribution: Piketberg to Cape Peninsula and Worcester

Habitat: Seasonal pools along slow-moving streams

IUCN Red list: Critically endangered

National red list: Critically Endangered

Life form: Geophyte (bulb, corm or tuber - seasonally dormant)

Comments: This aquatic geophyte grows only in vernal pools in the Western Cape. Vernal pools are ecologically distinct from its surrounding areas and can be separated from other vernal pools by more than 100 km. These habitats have been severely transformed by human activity, which has been detrimental to many of the species which occur in it. Oxalis natans’ restriction to these seasonally wet habitats makes it very vulnerable to habitat loss. This species is also very sensitive to any change in water-flow in its habitat, which possibly contributed to the extinction of many populations. Very few populations are known to still exist. For long there was only two known populations, one of which occurred on a highly disturbed site. In 2020, two other populations were found, which is very good news for the future of this Critically Endangered species.