Satyrium rhodanthum Schltr.
Common names: None recorded
The Critically Endangered Satyrium rhodanthum grows into a tapering, majestic beauty with flamboyant pink or red flowers.
This exuberant orchid grows in moist grasslands to heights of about 250 to 400 mm. The plant has 2, upright or expanding leaves which are near the base on a barren shoot that grows once flowering has occurred. The stem is clothed by sheaths which occur when the stem is enveloped by the tubular part of the leaf.
The inflorescence is concentrated with about 10 to 25, striking bright pink to crimson flowers. The existing bracts are egg-shaped, bent downwards abruptly and somewhat tapering gradually to a sharp point. The lower bracts are longer than the flowers when compared to the upper bracts, which are shorter. The sepals and petals are about 13 mm long and bent downwards. These organs are connivent but not fused. The sepals situated at the middle are marginally thicker than the others, and those situated on the sides, vary in shape, from longer than broad, to slender with parallel margins for most of the length.
The protruded part of the flowers, where the petals and sepals attach forming a tube, is hollow and convex. The flap is flat, almost square-shaped, but blunt, and bears soft, nipple-like projections. It contains margins that are toothed. Spurs (which are slender, threadlike, hollow extension of the perianth that contains nectar) are present and bent abruptly downwards. The spurs are twice the length of the ovaries. Stigma flaps are either wedge-shaped or almost square-shaped. They are 2-liped and have a beak-like projection.
According to SANBI’s Red List of South African plants, Satyrium rhodanthum is currently listed as CE (Critically Endangered), as it is only known from one location where it is threatened by housing development. This species is threatened by the decline of its preferred habitat type — Mistbelt grasslands, due to housing and forestry expansion. The Custodians of Rare and Endangered Wildplants (CREW) programme, has been monitoring this species to gather much needed data.
Distribution and habitat
Satyrium rhodanthum is restricted to a portion of the Mistbelt grasslands in KwaZulu-Natal near Ixopo, where sugarcane farming and cultivated forests are prevalent. The region is characterized by mountainous terrain affiliated with an intermittent Eastern escarpment fashioned by igneous intrusions. Satyrium rhodanthum occurs in damp grasslands at altitudes between 700–1 100 m.
Derivation of name and historical aspects
Satyrium is a genus of orchids, founded by the Swedish botanist, taxonomist and orchid aficionado, Olof Swartz (1760–1818). The name Satyrium originates from Greek mythology. Satyr refers to group of divine entities that roamed and inhabited much of the forests and mountains environments. It is considered to be a hybrid between human and animal, in which the torso and upper parts of the body resembles that of a human and the lower parts of the body resemble that of a horse or goat. The Satyrs are also distinguished by their goat-like horns. It is reasonable to assume, that the name Satyrium, may refer to the identical horn-like appendages which arise from the lip of the flower, which is a distinguishing characteristic of the genus.
Satyrium rhodanthum was first described by the German botanist and orchid taxonomist, Friedrich Richard Rudolf Schlechter (1872–1925), who dedicated his life to the Orchidaceae and Asclepidaceae families. The very first specimen collected was by a German horticulturist, August Gottlieb Hans Rudatis (1875–1934), on the 12 October 1904, in Alexandra District. The species name rhodanthum, is of Latin origin, meaning with ‘rose-coloured flowers’. This is understandably a reference to the colour of the inflorescence.
Satyrium rhodanthum is a terrestrial orchid which persists in the summer-rainfall region of South Africa. Orchids are illustrious for their extremely specialized pollination systems. Although birds as a pollinating agent, is uncommon in orchids; it was recently determined that the genus Satyrium is pollinated by birds, distinguishing it from other orchid genera. Satyrium rhodanthum like many others in the genus, are pollinated by Amethyst sunbirds, who are attracted to the plant because of its attractive floral colours, odourless nature and high concentrations of diluted nectar.
Satyrium rhodanthum has an extended nectar tube which enables the birds to extract nectar with ease. The pollen accumulates in the sectile pollinia which stores massulae (the yellow, dry and cone-shaped pollen microspores). Pollination occurs from the morning till mid-afternoon. The fruit of Satyrium rhodanthum become apparent approximately six weeks after pollination has occurred.
There is no record of traditional, economic or medicinal uses thus far.
Growing Satyrium rhodanthum
Satyrium rhodanthum, like most Satyrium species, can be challenging to grow. It has recently come to the attention of South African horticulturists and gardening enthusiasts, that soils utilized from previously grown terrestrial orchids, have the potential to facilitate the development of species from the genus Satyrium. These soils contain a type of fungi that assists with the germination and the nourishment of the young Satyrium species. People who are unable to obtain soils with the fungal component can utilize well-drained terrestrial compost. This is fundamental for the development of species, because the plant needs a sufficient amount of both air and water. The soil must be placed in a partially shaded garden pot. It is important that the growing environment is more or less consistent with the natural conditions to which the plant is accustom. Water should be added when necessary during the growing phase, however, you should be cautious, to not over saturate the pot with water and allow the plant to accumulate water on the leaves, which could serve as a chalice, and may facilitate the decay of the leaves. The soil in the pot should dry out before replenishing the plant’s water supply.
Satyrium rhodanthum grows predominantly in summer rainfall areas. In the winter months it is essential that the plant be kept in a cool, dry environment. Satyrium rhodanthum begins to develop in September–October, and flowers in the summer months (November–December). This is apparent as advances in the inflorescences and the succulent leaves become evident. The leaves develop after flowering.
- Johnson, S. & Bytebier, B. 2015. Orchids of South Africa: a field guide. Penguin Random House South Africa.
- Kurzweil, H. & Linder, H.P. 1999. Orchids of southern Africa. Balkema, Rotterdam.
- Shaw, C.S., & Escott, B. KwaZulu–Natal Vegetation Type Description Document for Vegetation Map 2011: kznveg05v2_1_11_wll. shp.
- Scott-Shaw, C.R. & Victor, J.E. 2005. Satyrium rhodanthum Schltr. National Assessment: Red List of South African plants version 2014.1 . [Accessed on 2015/07/21]
- http://plants.jstor.org/stable/10.5555/al.ap.person.bm000007503 . [Accessed on 2015/07/22]
- http://plants.jstor.org/stable/10.5555/al.ap.person.bm000042646 . [Accessed on 2015/07/22]
- http://www.africanorchids.dk/orchidoideae/tribe-diseae/subtribe-satyriinae/satyrium . [Accessed on 2015/07/22]
- http://davesgarden.com/guides/botanary/go/9260/ . [Accessed on 2015/07/22]
- http://www.academia.edu/3114658/OLOF_SWARTZ_A_250_YEAR_ANNIVERSARY. [Accessed on 2015/07/24]
- http://www.pantheon.org/articles/s/satyrs.html . [Accessed on 2015/07/24]
- http://bugs.bio.usyd.edu.au/learning/resources/Mycology/Plant_Interactions/Mycorrhizas/Orchid/orchidFunction.shtml . [Accessed on 2015/07/24]
SANBI, Custodians of Rare and Endangered Wildflowers (CREW) programme – KZN Node
Plant Type: Orchid
SA Distribution: KwaZulu-Natal
Soil type: Sandy
Flowering season: Early Summer
Flower colour: Red, Pink
Aspect: Morning Sun (Semi Shade)
Gardening skill: Challenging