The Cape Sundew (Drosera capensis) is a charming carnivorous plant, with its long, narrow leaves covered by reddish tentacles that glisten like dewdrops under the light. Native to South Africa, this species presents a visual spectacle as it precisely captures insects. Among collectors, it stands out not only for its exotic beauty but also for its easy maintenance and its generous propagation. The Drosera capensis reveals itself as a living gem, combining delicate beauty with the relentless operation of a natural trap.
It is one of the easiest carnivorous plant species to grow, tolerating a wide range of light and humidity conditions. Additionally, its self-pollination ability and abundant seed production facilitate propagation, allowing collectors to expand their collections with relative ease. The diversity of shapes and colors available, such as the ‘Alba’ variety with white flowers and the intensely red ‘All Red’ variety, further increases its appeal among exotic plant enthusiasts.
Originally from the southwestern region of South Africa, Drosera capensis is endemic to the Cape Province. Its natural habitat includes wet areas such as marshes, stream banks, and zones of permanent infiltration, often associated with the fynbos biome, characterized by shrub vegetation and acidic soils poor in nutrients. These environments are ideal for the development of carnivorous plants, which compensate for the soil’s nutrient scarcity by capturing and digesting insects. The plant prefers locations with high humidity and direct or partial sun exposure, conditions that favor the production of the essential sticky mucilage for its feeding.
The botanical name Drosera capensis has an etymological origin reflecting distinctive characteristics of the plant and its geographical location. The genus “Drosera” derives from the Greek “drosos”, meaning “dew”, in reference to the shiny droplets of mucilage that cover the leaf tentacles, resembling morning dew. The specific epithet “capensis” indicates the plant’s origin, referring to the Cape region in South Africa, where the species is native. This nomenclature was established by Carl Linnaeus in 1753, when the species was formally described in the work “Species Plantarum“.
Drosera capensis, or Cape Sundew, is a perennial herbaceous species, with a basal rosette growth habit and no prominent erect stem formation, although older individuals may develop a short central stem from which the leaves emerge in a spiral. Its roots are filiform, sparsely branched, and relatively shallow, primarily serving to anchor the plant and absorb water, but they have a limited role in mineral nutrition since the plant relies on the digestion of insects to meet its nitrogen and other essential nutrient needs. The root system is adapted to poor and moist soils, being tolerant to low oxygenation environments.
The growth of Drosera capensis is slow and continuous, focusing on the sequential production of new leaves from the apical meristem. The plant lacks branches and maintains a compact structure, which facilitates its adaptation to high light environments and limits water loss. The leaves are linear-lanceolate, ranging from 1.6 to 4.7 inches (4 to 12 cm) in length and about 0.2 to 0.4 inches (0.5 to 1 cm) in width, with revolute margins in some individuals. The adaxial surface of the leaves is covered with specialized glandular trichomes, called tentacles, regularly arranged along the leaf blade. Each tentacle has a spherical apical gland that secretes a viscous mucilage, rich in digestive enzymes such as proteases, phosphatases, and esterases.
The capture mechanism of the Cape Sundew is classified as active, with a slow response to mechanical stimulus. When an insect lands on the leaf and contacts the tentacles, they initiate a gradual movement of the leaf blade rolling towards the center, thereby increasing the contact area with the prey. Simultaneously, the mucilage traps the animal, while digestive enzymes begin to break down the macromolecules present in the prey’s body tissues. The released nutrients, especially nitrogenous compounds, are absorbed by specialized epidermal cells. The digestive process can last from a few days to a week, depending on the size and composition of the captured insect, after which the leaf partially returns to its original position.
Flowering in Drosera capensis usually occurs at the end of spring and during the summer, particularly under conditions of intense lighting and when the plant reaches maturity, which may be between the first and second year of cultivation, depending on environmental conditions. The inflorescence is a scorpioid cyme, with up to 15 flowers alternatively arranged along an erect floral stem that can reach between 8 and 12 inches (20 to 30 cm) in height. This stem develops from the center of the rosette, allowing the flowers to position themselves above the carnivorous leaves, thereby preventing potential pollinators from being accidentally captured.
The flowers are hermaphroditic (monoecious), actinomorphic, with radial symmetry, and have five free petals, usually of a light pink to lilac color, although cultivars such as ‘Alba’ feature white flowers. Each flower remains open for only one day, but the sequence of opening along the cyme can extend the flowering period for several weeks. The stamens are arranged in groups of five, with dorsifixed anthers that release pollen by longitudinal dehiscence. The ovary is superior, tricarpellate, trilocular, with axial placentation and a trilobed stigma.
Drosera capensis is self-pollinating, though it also accepts cross-pollination under favorable conditions. Self-pollination is facilitated by the proximity of the stamens and stigma during the end of the anthesis. After fertilization, the ovary develops into a dehiscent dry capsule, which opens through valves to release the seeds, generally within three to four weeks after flowering. The seeds are small, fusiform, with a reticulated surface and black color, showing high viability and germination facilitated in moist and illuminated substrates.
Drosera capensis has several cultivated forms that highlight its natural and ornamental variations, being very popular among collectors and nursery growers. Among the main varieties and cultivars available on the market are:
- ‘Alba’: characterized by the absence of anthocyanins, which gives its leaves a uniform green tone and the flowers a pure white color.
This variety is particularly appreciated by collectors due to its more delicate appearance and subtle contrast with other forms of the species. - ‘All Red’: notable for its intense reddish coloration throughout the plant, a result of a high concentration of anthocyanins in the leaves and tentacles. This form is visually striking and often featured in carnivorous plant shows and exhibitions.
- ‘Narrow Leaf’: features thin, elongated leaves with a more upright growth.
- ‘Wide Leaf’: has broader and more robust leaves, with a compact stature.
The Drosera capensis, or Cape Sundew, is capable of responding to mechanical stimuli in a relatively sophisticated manner, even without a nervous system. Physiological studies have shown that the tentacles react not only to touch but also to the presence of organic compounds on the surface of insects, intensifying movement and the secretion of digestive enzymes. It can also differentiate between non-food stimuli, such as raindrops or plant debris, thereby conserving energy.
Another notable characteristic is its impressive ability to sustain its population in controlled environments, with spontaneous seed germination frequently observed around adult specimens in cultivation pots. Although desirable in cultivation, this prolific nature can turn the plant into an invasive species in ecosystems outside its native distribution, as reported in areas of Australia and New Zealand where it was introduced inadvertently and began competing with local flora. For this reason, its introduction in natural areas should be avoided, and responsible cultivation encouraged among collectors.
When cultivated indoors, the Cape Sundew stands out for its constant flowering cycle and the curious dewy appearance that makes it one of the favorites among decorative carnivorous plants. In its native region, it is commonly grown outdoors, particularly in waterlogged areas of gardens or along the edges of bodies of water, where it can successfully grow partially submerged. In addition to its value as an ornamental plant, it is traditionally used in South African folk medicine, where extracts from the plant are used to relieve symptoms of mild respiratory infections, such as cough and bronchitis, although these uses still require scientific validation.
Drosera capensis, also known as Cape Sundew, presents relatively simple cultivation requirements, contributing to its growing popularity among carnivorous plant enthusiasts. Regarding light requirements, this species demands abundant light to maintain vibrant coloration and to ensure effective mucilage production. It should be grown under direct sunlight for at least four to six hours per day or in environments with intense artificial lighting, such as full-spectrum LED lamps. A lack of light results in elongated leaves, faded pigmentation, and reduced capture efficiency. Often, it may even reduce the plant’s ability to produce its mucilaginous droplets.
The species adapts well to subtropical and temperate climates, tolerating moderate temperature variations. The ideal range is between 59°F (15°C) and 82°F (28°C), but the plant can survive temperatures down to 41°F (5°C) without permanent damage. In colder regions, cultivation should be done in greenhouses or indoors, protected from frost. The ideal substrate is nutrient-poor, acidic, and well-drained. Recommended mixtures include equal parts of sphagnum peat and washed quartz sand, possibly enhanced with perlite for better aeration. Topsoil, organic compost, or conventional fertilizers should not be used, as excess minerals can lead to root necrosis.
Planting should be done in plastic pots or other non-porous materials, with drainage holes, and kept on trays filled with distilled or deionized water, preferably by capillarity. Watering should be constant, keeping the substrate always moist. Tap water irrigation should be avoided, except in areas with low hardness and without chlorine and fluorine. Cape Sundew does not require staking, foliar or soil fertilization. Instead, nutrition occurs through the capture of insects, with occasional exposure to small arthropods like fruit flies or ants being sufficient. In enclosed environments, such as terrariums, the addition of small freeze-dried prey or live food from breeding facilities can complement their diet.
Pruning is generally unnecessary, but dried or damaged leaves can be carefully removed to prevent the accumulation of decomposing organic matter. General maintenance involves ensuring a clean environment, good air circulation, and constant lighting.
Flowering does not compromise the vitality of the plant, but it can be controlled if there is an interest in focusing energy on vegetative growth. The use of fertilizers or growth regulators is not necessary.
Regarding environmental resistance, Cape Sundew tolerates moderate temperature variations and direct sunlight exposure, provided there is high relative humidity in the air. It withstands gentle winds but may experience leaf desiccation under hot and dry winds. It is not tolerant to drought, being sensitive to prolonged dehydration. Exposure to frost may cause foliar death, although the root survives in protected substrates.
The species is little susceptible to pests, but it can suffer from aphids, scale insects, and fungi in poorly ventilated environments or with excess stagnant moisture. Fungal diseases such as powdery mildew and rot may occur, particularly in pots with compacted or contaminated substrate. Prevention includes good ventilation, appropriate lighting, and removal of dead leaves. In case of infestation, and when manual removal is not possible, it is recommended to use insecticides and fungicides specific for sensitive plants, preferably organic or in minimal dilutions. Products such as soaps or detergents should never be used on Cape Sundews, as these substances harm the mucilaginous droplets on the plant, dissolving them.
Propagation of Cape Sundew is simple and efficient through seeds, by dividing clumps or by regeneration from leaves. Sowing should be done in moist, sterile substrate, with seeds dispersed on the surface, without coverage, kept under constant light and high humidity. Germination usually occurs between 10 and 30 days after sowing. Division of adult plants is recommended at the end of the flowering period, carefully separating the rosettes formed at the base. Propagation by leaves can be done by detaching a healthy leaf, which, placed on moist substrate and under good light, can emit shoots within two to four weeks. The average time to first flowering, from germination, ranges from six to twelve months, depending on cultivation conditions.
