Holothrix is a genus of 55 species in the Orchidaceae family that occurs in Africa. Species are tuberous and have minute flowers and one or two often hairy, round to oval leaves that grow flat on the ground. Stems are usually hairy. Petals and lips are often multilobed. Flowering usually occurs in spring or summer, but there are species that grow in winter rainfall, summer rainfall, and both.
Holothrix aspera is found in deep sandy soils or rock pavements from Namaqualand and the western Karoo to Swellendam, South Africa. It is a winter rainfall species that grows to 10 cm. and has two round leathery leaves that are pressed to the ground. The white flowers on hairy spikes have a lip that is divided into 5 to 7 rounded lobes, with a short curled spur. Photo 1 taken by Mary Sue Ittner in the Komsberg of what she believes is this species. Photos 2-3 taken September 2011 near Carolusberg in Namaqualand by Cameron McMaster.
Holothrix incurva is found in damp crevices and ledges in cliffs at 1500 to 2900 meters in the summer rainfall Drakensberg Mountains in South Africa. It has yellowish hairy sepals and a hairy leaf and stem. The lip of the flowers is deeply divided into 5 slender lobes. Photos taken by Cameron McMaster at Sentinel Peak. In one of the photos this species is pictured with Hesperantha scopulosa.
Holothrix scopularia is found on exposed, often rocky, grassland at higher altitudes in the Eastern Cape of South Africa in the Drakensberg Mountains. It grows to 34 cm. and is covered in spreading hairs. The inflorescence is dense with small white to dull yellow or pink flowers all arranged on one side. The lip is deeply divided into 5 to 11 slender lobes. Photos taken by Mary Sue Ittner and Cameron McMaster on Naude's Nek in the Drakensberg.
Holothrix thodei grows in moist rocky grassland or rock crevices from 1500-2600 meters in the summer rainfall Drakensberg Mountains in South Africa. It has hairy leaves and yellowish to brownish green flowers with a short 3-lobed lip and a stem with long downward pointing hairs. It blooms January through March. Photos taken by Cameron McMaster at Aurora Peak, Maclear.
Holothrix villosa is found on sandstone and granite slopes and pavements. It is widespread, occurring from Namaqualand, the Western, Southern, and Eastern Capes and the Western Karoo of South Africa to Zimbabwe. It therefore occurs in both summer and winter rainfall areas. It has 2 basal ovate hairy leaves and green flowers in a dense raceme. Photos taken near Caledon in the Overberg by Cameron McMaster.
For more information on this genus consult the Holothrix page on the South African Biodiversity Institute web site.