Pachypodium saundersii – Pachypodium Saundersa
Pachypodium saundersii is one of the most distinctive caudiciform succulents of southern Africa and also one of the few mainland representatives of a genus that is otherwise mostly associated with Madagascar. The genus name comes from the Greek words pachys (thick) and pous, podos (foot), referring to the swollen, water-storing base of the stem. The specific epithet commemorates Sir Charles James Renault Saunders (1857–1931), a colonial official and plant collector from Natal, who collected the type specimen in the Lebombo Mountains in 1891. The species was described by Kew botanist Nicholas Edward Brown; for some time, it was treated as a subspecies of Pachypodium lealii from Angola and Namibia, but Plants of the World Online now recognizes it as a distinct species.
In English, the plant is known as kudu lily and Lundi star, after the Lundi (Runde) River in Zimbabwe. It reached collectors relatively late, but quickly gained a reputation as one of the most rewarding pachypodiums: it grows faster than most Madagascan species, tolerates container cultivation well, forms a thick caudex early, and flowers regularly. It is a plant for enthusiasts of succulents, caudiciforms, and succulent bonsai who can provide it with plenty of sun in summer and a dry, cool winter dormancy.
Botanical description and plant habit
Pachypodium saundersii is a low, succulent shrub 0.5–1.5 m tall, although plants in the wild are sometimes wider than they are tall, spreading to 1–2 m in diameter. The base of the plant consists of a large, tuberous, often irregularly flattened caudex with smooth, silvery-gray or light brown bark, from which one to several thick, fleshy stems emerge. The stems branch and taper upward, and are covered along their entire length with pairs of sharp, straight spines 2–7 cm long, which are modified stipules; the spines persist for years and give the plant a rugged, defensive appearance.
The leaves are alternate, clustered at the ends of the stems, shortly petiolate, elliptic or obovate, 3–8 cm long, glossy, dark green on the upper surface and lighter beneath, with a prominent midrib. The plant is seasonally deciduous: during the dry, cool season, the stems remain bare, and all assimilation takes place in the greenish bark of young growth. The light color of the bark is not accidental; it reflects part of the solar radiation and protects the water-storing tissues from overheating. The plant sap is colorless to slightly milky and, as in all members of the dogbane family, highly poisonous.
Growth rate and development
Compared with other species in the genus Pachypodium, this species is considered relatively fast-growing. Young plants develop a noticeably thickened base already in their first season, and with high temperatures, plenty of light, and regular watering, they can double in size within a few months. In subsequent years, height growth slows, while the caudex steadily thickens and develops character; ten- to twenty-year-old specimens grown in pots usually reach 30–60 cm in height, with a caudex several centimeters in diameter. Unlike many Madagascan pachypodiums, this species readily branches on its own, even without damage to the growing tip.
The annual development cycle is strictly seasonal. In spring, as temperatures rise, the shoots produce new leaves and the plant enters a period of intensive growth lasting throughout the summer. In autumn, when the days become shorter and cooler, the leaves turn yellow and fall, and the plant enters dormancy lasting about three months. This rhythm is embedded in the species' physiology and should not be disrupted: plants kept warm and moist in winter become weak, grow elongated, and fail to flower. Pachypodium saundersii is a long-lived plant; specimens several decades old are known both in nature and in collections.
Flowering and propagation
The flowers appear at the shoot tips in dense clusters of several to more than a dozen blooms. They are large for the size of the plant, about 5 cm in diameter, funnel-shaped, with five broadly spreading, slightly twisted petals. They are white with a pink or purple flush, strongest on the outer surface of the petals and in the bud; the flowers are delicately fragrant and attract insects, especially butterflies and moths. In South Africa, the plant flowers from autumn to early winter, while in cultivation in the Northern Hemisphere it most often flowers from late summer into autumn, often after shedding its leaves, making the bare, spiny shoots crowned with white flowers particularly striking.
The fruit consists of paired, horn-like, spreading follicles several centimeters long. When mature, they split along one seam and release numerous small, flattened seeds with a tuft of whitish hairs at one end. The hairs act like parachutes and enable wind dispersal over considerable distances, allowing the plant to colonize rock crevices in hard-to-reach places. In cultivation, the plant is propagated primarily from seeds; stem cuttings root less readily, and plants grown from them do not develop as attractive a caudex as seedlings.
Environmental Requirements and Tolerance
The species’ natural range includes the eastern part of South Africa (KwaZulu-Natal, Mpumalanga, Limpopo), Eswatini, southern Mozambique and southern Zimbabwe, with its distribution centered in the Lebombo Mountains and the adjacent lowveld lowlands. Plants grow on rocky slopes and outcrops, often directly in rock crevices, in full sun among dry thickets and open woodlands. The climate in these regions is hot, with rainfall concentrated in summer and a distinct dry winter, during which nighttime temperatures drop, but frost is rare and short-lived.
This results in the following tolerance profile: the plant tolerates full sun, high temperatures, excellent drainage and long periods of drought extremely well, but reacts very poorly to constantly wet soil, especially in cool conditions. In cultivation, it is generally accepted that plants kept in dry soil tolerate brief drops to around 5 °C, while exceptionally large, fully dormant plants have even survived light frost; however, a safe winter minimum is 10 °C. The species is classified as USDA zone 10, and in zone 9b it can be grown outdoors in the ground only with protection and complete dryness. It has low humidity requirements and tolerates the dry air found in homes well.
Cultivation in Temperate Climates
In cooler regions of Europe, Pachypodium saundersii is grown exclusively in containers, following a cycle that mimics its natural conditions. From late spring to early autumn, the best location is in full sun outdoors, on a balcony, terrace or in the garden, protected from heavy rain; plants accustomed to indoor conditions should be gradually acclimatized to avoid sunburn. Throughout the season, the plant should be kept in mineral, very free-draining soil, such as a mixture of cactus soil with pumice, lava or gravel, in a pot with large drainage holes. Water thoroughly, but only after the soil has dried out completely; during warm, sunny weeks, you can feed it with diluted succulent fertilizer every 4–8 weeks.
In autumn, as the leaves turn yellow, gradually stop watering and move the plant to a bright, cool room at 10–15 °C, where it should overwinter almost completely dry. If cool overwintering is not possible, the plant can remain warm on a sunny windowsill, but it will usually retain some of its leaves and require occasional, sparing watering, preferably supplemented with grow lights. In spring, when new leaves appear, resume watering cautiously. Repot every 2–3 years at the beginning of the growing season, wearing gloves because of the spines and poisonous sap. The most common problems are root and stem-base rot after overwatering in cool conditions, as well as mealybugs and spider mites in dry, warm interiors.
Use in ornamental gardening
Pachypodium saundersii is a collector's plant and one of the most popular species used in succulent bonsai. Its natural tendency to form a thick, irregular caudex and branched, spiny shoots makes it possible to obtain an impressive specimen in a relatively short time. Plants are displayed in low, wide ceramic bowls with a mineral top layer, alongside rocks, in caudex collections next to adenium, Pachypodium lamerei, or Operculicarya. In warmer regions with a Mediterranean or subtropical climate, it is planted in rock and succulent gardens as an accent plant, where it eventually forms wide, flowering clumps. In Eswatini, the plant was sometimes used in folk medicine, including for toothache, although due to its toxicity this practice is not recommended.
Who this species is for
This species is suitable for enthusiasts of succulents, cacti, and caudex plants who want to grow a bonsai-style specimen from scratch, as well as for people with a very sunny location and the ability to provide cool, dry overwintering. It is a good choice for gardeners with some experience growing succulents who understand the principle of watering after the substrate has dried and respect the dormant period. Due to its spines and poisonous sap, it is not suitable for homes with small children or pets that tend to nibble on plants.
Summary
Pachypodium saundersii combines features that rarely occur together: an impressive caudex, relatively fast growth, moderate size, and regular, fragrant flowering. It requires sunlight, a mineral substrate, and consistent adherence to the growth-dormancy cycle, and in return remains an ornament of the collection for decades. On the Red List of South African Plants, the species is classified as Least Concern, although it has lost around one-fifth of its habitat in parts of its range due to invasive plants and collection from the wild. Therefore, growing specimens raised from seed is the best way to enjoy this plant without putting pressure on wild populations.
