Origin and Habitat: Toliara, Southwestern Madagascar.
Type locality: Near Tulear.
Habitat: It grows in thickets of Didierea madagascariensisSN|11208]]SN|11208]] on limestone substrata.

• Stapelianthus hardyi Lavranos

• Stapelianthus montagnacii (Boiteau) Boiteau & Bertrand
• Stapelia montagnacii Boiteau
• Stapelianthus hardyi Lavranos
• Stapelianthus montagnacii f. cristata hort.

Notes: Stapelianthus hardii forms a complex with Stapelianthus madagascariensisSN|19215]]SN|30460]] and Stapelianthus montagnaciiSN|19215]]SN|19215]], all three species being found only in the south west of Madagascar. In particular it is difficult to separate it from Stapelianthus montagnaciiSN|30460]]SN|19215]]. Both then share the same thicker stems, the darker colour of the corolla and the outer corona lobes that are only bifid in their upper third. Stapelianthus hardyi distinguishes for the somewhat darker, deeply bowl-shaped flower, slightly thicker corolla, longer papillae on the corolla with spherical apical "bristle" and slightly larger pollinia. However population with intermediate characteristic between the two are known and the most suitable arrangement is to place S. hardyi and S. montagnacii together.

Bibliography: Major references and further lectures
1) Werner Rauh, Herman Schwartz “Succulent and xerophytic plants of Madagascar” Volume 2 Strawberry Press, 1998
2) Boiteau, P. & J. Bertrand: "Stapelianthus montagnacii et Bertrand comb. nov." Cactus (Paris) 26:116 1950
3) Boiteau: Bull. Trimestriel Acad. Malgache n.s., 24:83.1942
4) James Cullen, Sabina G. Knees, H. Suzanne Cubey “The European Garden Flora Flowering Plants: A Manual for the Identification of Plants Cultivated in Europe, Both Out-of-Doors and Under Glass” Cambridge University Press, 11/Aug/2011
5) Hermann Jacobsen “A handbook of succulent plants: descriptions, synonyms, and cultural details for succulents other than Cactaceae", Volume 1 Blandford Press, 1960
6) Bruyns, P.V. & C. Klak: “Revision of the Madagascan Endemic Stapelianthus (Apocynaceae) Based on Molecular and Morphological Characters.” Annals of the Missouri Botanical Garden 91(3):410-437. Oct., 2004
7) Bruyns, P.V. "Stapeliads of Southern Africa and Madagascar" Volume I Umdaus Press, Hatfield, South Africa Pages 257 - 259 2005
8) Focke Albers, Ulrich Meve “Illustrated Handbook of Succulent Plants: Asclepiadaceae” Volume 5 Springer, 2002
9) Sajeva, Maurizio and Costanzo, Mariangela. "Succulents: The Illustrated Dictionary" Portland, Ore.: Timber Press, 1994.
10) James Cullen, Sabina G. Knees, H. Suzanne Cubey “The European Garden Flora Flowering Plants: A Manual for the Identification of Plants Cultivated in Europe, Both Out-of-Doors and Under Glass” Cambridge University Press, 11/Aug./2011

Cultivation and Propagation: Stapelianthus hardyiSN|19217]]SN|19217]] is a xerophytic plant adapted to dry soils, but despite its provenance it is without doubt an easy species to grow and not difficult as commonly supposed only bearing in mind that this species benefits from slightly warmer winter than others.
Growth rate: It is a relatively rapidly growing and easily flowering species that will make large clumps given the best conditions. Most plants will offset readily, and clumps can be produced in a few years.
Soils: It likes very porous mineral cactus mix soil, pH 7,5 to 8,5 (mildly alkaline), but can become too elongated if compost is too rich.
Repotting: This plant needs plenty of space for its roots, repotting should be done every other year or when the it has outgrown its pot. Use pot with good drainage.
Watering: It needs regular watering, especially during the hottest summer days; provide also some light watering if the green house temperatures in winter are elevated. Either excessive or very scarce watering can induce rot.
Fertilization: Feed with a high potassium fertilizer in summer.
Frost Tolerance: For safe cultivation it is best to avoid freezing temperatures (minimum 5° C). In the rest period no high atmospheric humidity!!
Sun Exposure: Best for half-shade but grow well in full sun and full shade too. Tends to bronze in strong light, which encourages flowering, but is likely to suffer from sun scorch or stunted growth if over exposed to direct sunlight during the hottest part of the day in summer.
Diseases: This species is relatively resistant to cryptogamic diseases than others and is quite resistant to the “Balck spot” disease of Asclepiads. Rot it is only a minor problem with Stapelianthus hardyiSN|19217]]SN|19217]] if the plants are watered and “aired” correctly. If they are not, fungicides won't help all that much.
Uses: It is an excellent plant for container growing. Cascading, clustering, great for a hanging display. Stems may possibly become purple and limp in winter, but revitalize in early spring. It always looks good and stays small. It look fine in a cold greenhouse and frame or outdoor in a rockery.
Propagation: Seeds and cuttings. Cuttings will root only in hot weather. Cuttings must be kept very dry to root. Seeds germinate readily if they are sown when fresh.