Disa ferruginea also known as the cluster disa, is a species of orchid from South Africa.

Disa ferruginea
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Orchidoideae
Genus: Disa
Species:
D. ferruginea
Binomial name
Disa ferruginea
Sw.[1]

Description

edit

Disa ferruginea is a sturdy, reed-like terrestrial plant that typically grows between 200 and 450 mm tall. It has linear radical leaves that develop after flowering, while the dry cauline leaves form sheaths. The inflorescence is dense, with 1 to 40 flowers. The flowers themselves are bright red to orange, often with some yellow components. The median sepal has an apiculate tip, and a galea (hood-like structure) is 8 to 10 mm deep. The slender spur of the flower grades into the galea and measures 7 to 20 mm long. The lateral sepals project outward and are elliptic to narrowly elliptic, with apiculi that can reach up to 4 mm in length. The petals are spear-shaped and 5 to 7 mm long, while the lip is narrowly egg- to spear-shaped and 10 to 12 mm long.[2][3]

Distribution

edit

The species is endemic to the South-Western Cape of South Africa, specifically in the fynbos vegetation.

Habitat

edit

Disa ferruginea is occasionally or commonly found in dry to slightly damp areas, usually in the zone of the southeaster clouds, ranging from 400 to 1,500 m. It is pollinated by the mountain pride butterfly and hybridizes very rarely with D. graminifolia. The plant blooms between February and March, with fire serving as a stimulus for flowering.

Pollination

edit
 
Aeropetes tulbaghia, the cluster disa's only pollinator.

The species is exclusively pollinated by the mountain pride butterfly (Aeropetes tulbaghia). It does not produce nectar for the butterfly, instead deceiving it by mimicking the flowers of species that do produce nectar. In south-western Cape, a red-flowered form mimics the red reedpipe (Tritioniopsis triticea), while in the Langeberg Mountains, an orange-flowered form mimics the red hot poker (Kniphofia uvaria).[4]

Disa ferruginea is most closely related to either Disa porrecta or Disa gladioliflora, both of which also use deceptive mimicry to lure its pollinators. The former is another red-flowered and butterfly-pollinated species, while the latter is pink-flowered and pollinated by flies and Amegilla bees.[5][6]

References

edit
  1. ^ International Organization for Plant Information (IOPI). "Plant Name Details". International Plant Names Index. Retrieved 2022-10-13.
  2. ^ "Disa ferruginea Sw". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 13 October 2022.
  3. ^ "Name - Disa ferruginea Sw". Tropicos. Retrieved 2022-10-13.
  4. ^ Johnson, S. D. (1994-09-01). "Evidence for Batesian mimicry in a butterfly-pollinated orchid". Biological Journal of the Linnean Society. 53 (1): 91–104. doi:10.1006/bijl.1994.1062. ISSN 0024-4066.
  5. ^ Johnson, S. D.; Linder, H. P.; Steiner, K. E. (March 1998). "Phylogeny and radiation of pollination systems in Disa (Orchidaceae)". American Journal of Botany. 85 (3): 402–411. doi:10.2307/2446333. ISSN 0002-9122.
  6. ^ de Jager, Marinus; Newman, Ethan; Theron, Genevieve; Botha, Pieter; Barton, Madeleine; Anderson, Bruce (April 2016). "Pollinators can prefer rewarding models to mimics: consequences for the assumptions of Batesian floral mimicry". Plant Systematics and Evolution. 302 (4): 409–418. doi:10.1007/s00606-015-1276-0. ISSN 0378-2697.
edit