Stapelianthus Choux ex White & Sloane
This genus is found exclusively on the island of Madagascar, and is named for the genus Stapelia which is not found there, and the Greek 'anthos', flower. The plants are clump forming perennials with slender cylindrical stems. Characters of the stems and flowers indicate a close relationship with the genus Huernia, but flower morphology more favours the genus Tavaresia.
Stapelianthus decaryi
The thin stems of this species from the south of the island, are a dark grey green and 6 ribbed. Its tiny leaf rudiments dry to form small spines.
The stems of this procumbent creeping species have a tessellated, uneven surface. The species forms a complex with S. madagascariensis and S. montagnacii, all three species being found only in the south west of the island.
Stapelianthus madagascariensis
A procumbent creeping species from southern regions of the island
Stapeliopsis Pillans
Named from Stapelia and the Greek '-opsis'; similar to. The genus is confined to South Africa and Namibia. From my experience the Namibian species seem to be particularly difficult to cultivate in northern Europe.
Stapeliopsis neronis
The purple marbling on the blue green four angled stems make this species from southern Namibia and the Northern Cape particularly attractive.
Recently given species status this plant with sharply four angled stems from the Western Cape was previously Stapeliopsis saxatilis ssp stayneri. The plant shown is PVB1263 from Grasrug, Infanta, 5km north of the Breede River mouth.
Stathmostelma K.Schum.
A genus of around 30 tuberous rooted perennial shrubby species with a distribution across tropical Africa closely related to both Asclepias and Gomphocarpus. The name derives from the Greek 'stathmos' plumb line and 'stelma' crown or garland, for the straight appendages of the inner corona segments.
Stathmostelma gigantiflorum
Coming as it does from seasonally inundated meadow lands in Tanzania, this species likes plenty of water in the growing season.
Stephanotis Thou.
Derived from the Greek 'stephanos', crown and 'otis' ear, referring to the crown of stamens which have outgrowths fancifully like ears. In the subfamily Marsdenieae the genus is distributed in Madagascar, southern Asia east to Malaysia and in Peru, the genus consists of 15 species of woody climbers with leathery textured leaves and jasmine like tubular flowers.
Stephanotis floribunda
From the island of Madagascar, this species is an evergreen climber which would grow to 5 meters or more but can be maintained at about 60cm (2ft) by winding it around a low support. The plants can survive a winter temperature around 10°C, but much prefer a temperature above 13°C. They also benefit by the addition of some extra peat in the compost mix.
Stomatostemma N.E.Br.
The name derives from the Greek 'stoma' mouth and 'stemma' wreath for the growths on the corona at the mouth of the corolla tube. The genus in the Periplocoideae has only two species, seemingly linked only by similarities in the corona morphology, as Stomatostemma pendulina is a shrubby non-succulent species whilst Stomatostemma monteiroae is a succulent tuberous rooted liana which in cultivation will flower at as little as 10 cm in length. S. pendulina is found only in Mozambique, whilst S. monteiroae can also be found in Botswana, South Africa, Swaziland, Zambia and Zimbabwe.