Stapelia leendertziae

Stapelia leendertziae — commonly known as the Black Bells Stapelia — is one of the most dramatic and sought-after species in the genus. Native to the rocky, arid regions of South Africa, it produces tall, upright, ribbed stems of rich green that form attractive clumping mounds reaching 20–30 cm in height. Its defining feature is its extraordinary flower: a large, deeply lobed, bell-shaped bloom in deep burgundy to near-black, with a velvety, hair-fringed texture that is unlike almost anything else in cultivation. A true collector's specimen and a guaranteed conversation piece.

Note on fragrance: Like all Stapelia, S. leendertziae flowers emit a carrion-like scent to attract fly pollinators. The odor is brief and localized — most noticeable when the flower first opens — and is widely considered a worthwhile trade-off for such a spectacular bloom.

Care Guide

Light

Full sun to bright indirect light is ideal. S. leendertziae thrives in a south- or west-facing window with several hours of direct sun daily. Strong light produces compact, robust stems and encourages blooming. In lower light, stems become etiolated and elongated, and flowering is significantly reduced. Outdoors in summer, it appreciates full sun with some afternoon shade in the hottest climates.

Water

Water thoroughly during the growing season (spring–summer), allowing the soil to dry out completely between waterings. Highly drought-tolerant, it stores water in its succulent stems. In fall, begin reducing watering. In winter, water sparingly — once a month or less — to mimic its natural dry season. Overwatering, especially in cool or low-light conditions, is the primary cause of stem rot and plant loss.

Humidity

Prefers low to moderate humidity, consistent with its arid native habitat. Average household humidity (30–50%) is ideal. Avoid high-humidity environments, which increase the risk of fungal issues and stem rot. Good air circulation is important.

Temperature

Thrives between 60–90°F (15–32°C) during the growing season. Tolerates brief dips to 40°F (4°C) when kept dry, but is not frost-hardy. A cool, dry winter rest period (50–60°F / 10–15°C) with minimal watering encourages blooming the following season.

Soil & Potting

Use a fast-draining cactus and succulent mix amended with extra perlite or coarse sand. Excellent drainage is non-negotiable — always use a pot with drainage holes. Terracotta or unglazed ceramic pots are strongly recommended, as they allow excess moisture to evaporate through the walls. Given its taller, more upright growth habit, a slightly deeper pot suits S. leendertziae well.

Fertilizer

Feed with a low-nitrogen, phosphorus-rich succulent fertilizer (quarter strength) once a month during the growing season (spring–summer). Do not fertilize in fall or winter. Avoid high-nitrogen formulas, which promote soft, rot-prone growth.

Blooming

Produces spectacular, large bell-shaped flowers in deep burgundy to near-black — deeply lobed and fringed with fine hairs for a velvety, almost otherworldly appearance. Blooming typically occurs in late summer to fall on mature plants. A cool, dry winter rest followed by increased watering and warmth in spring is the most reliable bloom trigger. Flowers last several days and are a truly remarkable sight.

Propagation

Propagate easily by separating offsets (pups) from the base of the plant, or by taking stem cuttings. Allow cut ends to callous for 2–3 days before placing in dry cactus mix. Root under warm, bright conditions with minimal watering until established.

Toxicity

Mildly toxic if ingested — as a member of the milkweed family (Apocynaceae), it contains compounds that may cause gastrointestinal irritation in pets and humans. Keep out of reach of pets and children.