Stapelia GIGANTEA

Stapelia GIGANTEA - Giant stapelia, Zulu giant, Carrion plant, Stapelia gigantea.

Stapelia is a genus of succulent plants in the family Apocynaceae, belonging to the stapeliad succulent group and comprising several dozen species distributed predominantly in Southern Africa and adjacent arid regions. Representatives of the genus occur in dry shrubland communities, savannas, rocky places, among grasses and low vegetation, where they receive bright light, good ventilation, and rapid soil drying.

The plants develop as low perennial succulents with fleshy branching shoots. The stems are usually four-angled or multi-angled, green, gray-green, brownish-green, or slightly blushing red in the sun, with toothed ribs and reduced leaves in the form of tiny scales. The root system is comparatively shallow, which is why stapelias are particularly sensitive to heavy, wet soil.

Flowers in stapelias are large or medium-sized, star-shaped, fleshy, often with spots, stripes, wrinkles, hairs, and a complex velvety surface. In many species, the flowers have a distinctive scent that attracts fly pollinators. After pollination, paired follicles form with numerous flat seeds equipped with a silky pappus for wind dispersal.

Giant stapelia has very large flowers. They sometimes reach 35 cm (14 in), the petals are more acute, and the flowers are light greenish-yellow, covered with numerous fine transverse reddish stripes. Special whimsical appeal is lent to the flowers by long hairs along the petal margins. The shoots are sturdy, erect, up to 20 cm (8 in) high and 3 cm (1.2 in) thick, with strongly developed wing-like angles bearing small, sparsely spaced denticles.

Stapelia seeds are flat, brown or dark brown, equipped with a long silky pappus that is carefully removed before sowing.

Before sowing, seeds can be soaked for 2-4 hours in a weak solution of potassium permanganate or biofungicide with the addition of a growth stimulant: SUPERthrive, HB-101, Aminozol, Epin, or Zircon. A sterile mineral seed-starting substrate based on cactus soil, fine perlite, and washed sand is used. Seeds are distributed over the surface, lightly pressed down, and covered with a thin layer of sand or sifted substrate about 1-2 mm (0.04-0.08 in).

The sowing is carefully moistened from a spray bottle, covered with a transparent lid or placed in a mini-greenhouse. Temperature is maintained at 22-26 °C (72-79 °F); lighting requires bright diffused light without direct overheating. Ventilation is carried out daily for 10-15 minutes, condensation is removed, and the substrate surface is kept slightly moist, but not wet.

The first shoots may appear in 7-14 days; usually germination takes 2-4 weeks, and under cool conditions can extend to 6-8 weeks. After shoots appear, the cover is gradually opened slightly, and seedlings are kept under bright diffused lighting, moderate warmth, and cautious watering. Pricking out is performed after seedlings strengthen and small fleshy shoots begin growing, when the plants are already convenient to transfer with a small clump of substrate.

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For Stapelia, bright diffused lighting with gentle morning or evening sun is used. East, southeast, and well-lit west windows are best suited, while on a south window in summer, protection from overheating and direct midday rays is required. With a lack of light, shoots stretch out, become thin, and set flower buds poorly, while under sharp overheating they can suffer sunburn.

During active growth, a temperature of 20-28 °C (68-82 °F) is maintained; with good ventilation, the plant tolerates summer heat. Wintering is preferred bright and cool, at 10-15 °C (50-59 °F), with very infrequent watering. The minimum safe temperature for a container plant is about 10 °C (50 °F) when kept dry. Cold, damp soil quickly causes rot of roots and shoot bases.

Watering is carried out cautiously, after complete drying of the soil. In the warm season, the plant is watered moderately, but without persistent dampness, and excess water from the drip tray must be drained after 15-20 minutes. During the cool dormant period, watering is curtailed sharply and performed only upon noticeable wrinkling of the shoots. Water must not linger at the base of the stems, and misting is generally not required.

The substrate used is very loose, mineral, and fast-drying: commercial cactus and succulent mix, coarse sand, fine gravel, pumice, zeolite, brick chips, perlite, and a small amount of leaf mold. A drainage layer at the bottom is mandatory. Pots are chosen shallow, wide, stable, with drainage holes, as roots in stapelias are usually shallow and especially sensitive to waterlogging.

Transplanting is carried out in spring, usually once every 2-3 years or after heavy expansion of the clump. Careful potting-on is used, removing old, damaged, or decayed shoots. After transplanting, the plant is kept for 5-7 days without watering. Fertilizer is applied only during the period of active growth once every 4-6 weeks with a weak solution of cactus and succulent fertilizer low in nitrogen. Excess nitrogen is undesirable because it causes soft watery growth and elevates the risk of rot.

Propagation in culture is most often carried out by stem cuttings. Cuttings are taken from mature shoots, dried in shade for at least several days, and for large cuts - up to 1-2 weeks, until the cut surface becomes completely dry. Then the cuttings are planted into dry or barely moist mineral substrate, and the first waterings are carried out very cautiously, only after rooting begins.