Disa bracteata
{{Short description|South African plant species in the orchid family}}
{{Speciesbox
| image = Disa bracteata flowers.JPG
| taxon = Disa bracteata
| authority = Sw.
| synonyms = *Disa micrantha (Lindl.) Bolus
- Disa praetermissa Schltr.
- Monadenia australiensis Rupp
- Monadenia bracteata (Sw.) T.Durand & Schinz
- Monadenia micrantha Lindl.
- Monadenia praetermissa Schltr.
| synonyms_ref = {{GBIF |id= 2783736|taxon= Disa bracteata |access-date=26 September 2023}}|
}}
Disa bracteata, also known as the bract disa, leek orchid or the South African weed orchid is a species of orchid native to South Africa.{{cite web |title=A weed in waiting |url=http://www.viridans.com/INTRO/waitingweed.htm |access-date=2009-09-07 |work=Introduced Plants & Animals of Victoria |publisher=Viridans}}
Description
This tuberous geophyte that typically grows up to {{Convert|30|cm|in|abbr=on}} tall, although there are records of taller specimens.{{Cite book |last1=Manning |first1=John |url=https://www.sanbi.org/sites/default/files/documents/documents/strelitzia-29-2012.pdf |title=Plants of the Greater Cape Floristic Region : 1: the core Cape flora |last2=Goldblatt |first2=Peter |date=2012 |publisher=South African National Biodiversity Institute, SANBI |isbn=978-1-919976-74-7 |location=Pretoria |oclc=852384288}} The linear-lanceolate leaves are {{Convert|4-12|cm|in|abbr=on}} long.e-Flora of South Africa. v1.42. 2023. South African National Biodiversity Institute. http://ipt.sanbi.org.za/iptsanbi/resource?r=flora_descriptions&v=1.42 They have a rounded base and sharply pointed tips.{{Cite book |last1=Clarke |first1=Hugh G. |url=https://www.worldcat.org/oclc/1124073483 |title=Wild flowers of the Cape Peninsula |last2=Merry |first2=Corinne |date=2019 |publisher=Struik Nature |isbn=978-1-77584-640-6 |edition=3rd |location=Cape Town |oclc=1124073483}}
Flowers are present between September and November. They grow in a many flowered cylindrical inflorescence that is {{Convert|2-12|cm|in|abbr=on}} long. The bracts are slightly longer than the flowers themselves. The flowers are bi-coloured with greenish-yellow lower sections and helmet-shaped maroon upper sections. The helmet-shaped sepals are {{Convert|2.5-4.5|mm|in|abbr=on}} long. The shallowly triangular spur is {{Convert|3-4.5|mm|in|abbr=on}} long. The pendent lip has an oblong to oblanceolate shape. The anther is also pendent and has a large notch in the rostellum.
Distribution and habitat
This species is endemic to South Africa, where it is found in the Western Cape and Eastern Cape. It is found from sea level to an altitude of {{Convert|2000|m|ft|abbr=on}} in Fynbos, Renosterveld and Albany Thicket habitats. It does particularly well in disturbed habitats, such as roadsides, where it is more common and occurs in higher densities than in undisturbed sites.
Disa bracteata is invasive in Australia.{{cite web|title=South African weed orchid|publisher=Victorian Resources Online|url=http://vro.agriculture.vic.gov.au/dpi/vro/vrosite.nsf/pages/weeds_herbs_perennial_african_weed_orchid|access-date=2019-10-29}} It is one of the few orchid species which has become naturalized in Australia.{{cite web |author1=Clements, Mark |author2=Jones, David |date=13 June 2008 |title=Australian Orchidaceae: Current Genera and species list |url=http://www.anbg.gov.au/orchids |access-date=24 September 2013}} It was first recorded in Western Australia in 1944, in South Australia in 1988, and Victoria in 1994. There is also a single recording in Tasmania. At sites where D. bracteata has invaded, there have been up to 80 individuals found per square metre in the area. The similarity of environmental conditions in Australia and South Africa has allowed D. bracteata, as well as many other species native to South Africa, to become naturalised in various parts of Australia.{{Cite journal |last1=Konowalik |first1=Kamil |last2=Kolanowska |first2=Marta |date=2018-12-20 |title=Climatic niche shift and possible future spread of the invasive South African Orchid Disa bracteata in Australia and adjacent areas |journal=PeerJ |language=en |volume=6 |pages=e6107 |doi=10.7717/peerj.6107 |issn=2167-8359 |pmc=6304271 |pmid=30595982 |doi-access=free }}
Ecology
This species is known to be capable of self pollination.{{Cite journal |last1=Johnson |first1=S. D. |last2=Linder |first2=H. P. |last3=Steiner |first3=K. E. |date=1998 |title=Phylogeny and Radiation of Pollination Systems in Disa (Orchidaceae) |journal=American Journal of Botany |volume=85 |issue=3 |pages=402–411 |doi=10.2307/2446333 |jstor=2446333 |issn=0002-9122|doi-access=free }}
Conservation
This species is considered to be of least concern by the South African National Biodiversity Institute (SANBI).{{Cite web |last1=Foden |first1=W. |last2=Potter |first2=L. |date=2005 |title=Disa bracteata Sw. National Assessment: Red List of South African Plants version 2020.1 |url=http://redlist.sanbi.org/species.php?species=2759-185 |access-date=26 September 2023 |website=SANBI Red List of South African Plants}}
References
{{Reflist}}
External links
- {{Commons-inline|italic=1}}
- {{Wikispecies-inline|Disa bracteata|Disa bracteata}}
{{Taxonbar|from=Q5281159}}