Spiranthes alticola

At this time of the year there are not many orchids flowering in South Australia but one that is just finishing is Spiranthes alticola. The genus Spiranthes, commonly known as Ladies Tresses, is found throughout Australia, Eurasisa and the Americas.The following description is an extract from South Australia’s Native Orchids 2011 DVD which is available from the Native Orchid Society of South Australi. 

Spiranthes alticola D.L.Jones

Swamp Spiral Orchid

Etymology: The name alticola means high dweller, referring to its distribution in Eastern Australia, in west Victoria and South Australia’s South East.  It also grows near sea level.

Synonyms: Previously included in Neottia australis R. Br., S. sinensis (Pers.) Ames and S. australis R.Br.

 

 

(These two pictures show the variation in colour.)

Description: Leaves 3-5, narrow lanceolate, shiny, erect at the base, to 15 cm long. Flower stem to 45 cm tall, slender, flexible, with several sheathing bracts.  The flowers are numerous in a dense spiral, pink with a white labellum, rarely all white.  Segments are 6-10 mm long, sepals somewhat triangular, petals lanceolate, together forming a short tube, the tips free and recurved, and the lateral sepals divergent.  Labellum with a broad, decurved crisped, pellucid mid-lobe, side-lobes erect small.  The flowers are faintly fragrant.

spiranthes-alticola-leavesrwl-92

(Leaves of Spiranthes alticola)

Flowering: Dec – Jan – Feb.

Similar Species: S. australis, S. sp. Late selfing-white.

Distribution: SL, KIx, SE; NSW, Vic, Tas.

Confined in South Australia to a few high rainfall, near coastal, often mountain locations, southward from the Adelaide Hills in the Southern Lofty region, extinct on Kangaroo Island, (one record only), and South East; also in New South Wales, Victoria and Tasmania.

Habitat: Restricted to peaty bogs and swampy creek-sides, often in locations that are inundated throughout winter; in some areas surviving in paddocks grazed by stock.

Distinguishing Features:  S. australis, which is from the eastern states and is not strictly a swamp plant, has smaller darker pink flowers with a narrow labellum.

  • The two South Australian forms treated here are regarded as distinct species as where they are sympatric they begin flowering at different times and do not intergrade. S. alticola is the more delicate of the two.

Notes:  The best specimens are found on mowed firebreaks adjacent to swamps.  When vegetative reproduction produces two clonal plants next to each other the spiral arrangement of one is often a mirror image of the other.  See Gallery.

Native bee pollinators work the spikes from the bottom upward but as the stigma becomes receptive well after the pollinia have matured this mechanism helps ensure outcrossing.

Plants do well in cultivation if kept moist over summer.

Conservation Status:

Status in Legislation: Not listed nationally, rare in South Australia.

Suggested Status: Rare in South Australia but more common in the Eastern States

 

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