Drosera capensis

Drosera capensis (), the Cape sundew, is a perennial rosette-forming carnivorous herb in the flowering plant family Droseraceae. It is native to the Cape region of South Africa, where it grows in permanently wet, nutrient-poor habitats. Its elongated, roughly oblong leaves are held semi-erect and have a distinct petiole. It is quite a variable plant with several recognised growth forms, some of which form a short stem. As in all sundews, the leaves are covered in stalked glands that secrete sticky mucilage. These attract, trap, and digest arthropod prey, obtaining nutrients that supplement intake from the substrate in which the plant grows. D. capensis has dramatically mobile leaves that curl around captured prey, preventing its escape and facilitating digestion.

First recorded in the late 17th century, D. capensis was one of the five Drosera species included in the first edition of Carl Linnaeus' Species plantarum. A relatively large, 'showy' species that flowers readily and is considered very easy to grow, it was cultivated in Europe as a curiosity from the mid-18th century and is now one of the most widely-grown sundews. It has also been extensively studied, including as a potential source of bioactive compounds of pharmacological interest, and was the first sundew to undergo whole-genome sequencing. Although often uncommon and localised in its native range, it has become naturalised in several countries following deliberate introductions, and is listed as an invasive species in New Zealand.

Characteristics

Habit

D. capensis is a perennial herb forming a rosette typically 10–15 cm (4–6 in) in diameter, although occasionally up to 30 cm (12 in). Its narrow, oblong leaves are held semi-erect. As in all sundew species, the laminae are covered with stalked glands ('tentacles') that secrete a sticky mucilage. These attract, trap and digest insects and other arthropods as 'prey'. New leaves grow from the centre of the rosette and the remains of old leaves gradually form a short stem, typically around 4 cm (1.6 in) in length but sometimes as long as 15 cm (5.9 in). The roots are sparse, thickened, and attain a length of about 15–20 cm (6–8 in), rarely branching. In summer, the plant produces one or two relatively tall inflorescences, each with between 15 and 30 flowers. The petals are typically pale purple.