Biology:Holothrix micrantha

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Short description: Orchid endemic to Gauteng, last seen in 1925

Holothrix micrantha
Holothrix micrantha.jpg
Holothrix micrantha specimen
Scientific classification edit
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Orchidoideae
Genus: Holothrix
Species:
H. micrantha
Binomial name
Holothrix micrantha
Schltr.

Holothrix micrantha is an orchid endemic to Gauteng, South Africa which was last seen in 1925. It is listed on the Red List of South African Plants as "Critically Endangered" and is regarded as possibly extinct— a result of the long absence since it was last recorded given searches have been undertaken in suitable habitat.[1]

Description

It is described as closely resembling Holothrix incurva but smaller, having a denser spike and petals of less than 5mm.[2] The scape has long, straight hairs without bracts; sepals with a few hairs at the tips; petals are undivided with carnose tips; leaves are pilose and withered at flowering; lips carnose divided into five linear, acute lobes; spur broadly conical, curved.[2]

Holothrix micrantha flowers between September and October.[2]

Distribution

Rudolf Schlechter located this species in 1893 on grassy cliffs above Heidelberg at an altitude of around 1800m.[3] Two other possible observations were located from Modderfontein and from a marsh in Killarney; although neither of these have been confirmed.[2] Urban expansion is blamed for destroying subpopulations, however, intact habitat remains in the Suikerbosrand nature reserve; other threats include inappropriate fire management as well as alien invasive plants.[1]

References

  1. 1.0 1.1 1.2 Mills, L.; von Staden, L. (2016). "Holothrix micrantha Schltr.". South African National Biodiversity Institute (SANBI). http://redlist.sanbi.org/species.php?species=2841-18. Retrieved 9 January 2020. 
  2. 2.0 2.1 2.2 2.3 Immelman, Kathleen (1979). A revision of the South African species of Holothrix Rich. ex Lindl. (Orchidaceae) (Master Thesis). University of Cape Town. hdl:11427/18105.
  3. Schlechter, R. (1898). "Revision der Gattung Holothrix. (Fortsetzung)". Österreichische Botanische Zeitschrift 48 (12): 441–448. doi:10.1007/BF01672773. ISSN 0029-8948. 

Wikidata ☰ Q15483671 entry