Thelymitra holmesii Nicholls

Slender Blue Swamp Sun-orchid

Victorian Naturalist 49: 263, t. 26 (1933) APNI

Taxonomic status:Accepted

Occurrence status:Present

Establishment means:Native

Flowering stem erect, straight, 18–75 cm tall, 1–2.6 mm diam., green to purplish. Leaf linear to linear-lanceolate, attenuate, (7–)15–35 cm long, 3–10 mm wide, fleshy, canaliculate, ribbed abaxially, sheathing at base, light to dark green with a purplish base. Inflorescence 1–9-flowered, open. Sterile bracts usually 2, rarely 3. Perianth segments lanceolate to ovate, (6–)8–11(–15) mm long, deep purplish blue to mauve. Column slender, 4.5–6.5 mm long, pale to dark mauve to pinkish; mid-lobe expanded into hood over the anther, tubular, compressed dorsally, gently curved, yellow with a purplish to black collar, apex deeply bilobed; lateral lobes converging or more or less parallel, 1–1.5 mm long, digitiform, porrect at base curving gently upwards, each with a sparse shaggy toothbrush-like arrangement of cream or yellow hairs terminating in front of mid-lobe. Anther inserted about mid-way along column, shortly beaked. Flowers Oct.–Dec.

CVU, DunT, EGL, GipP, Glep, Gold, GGr, HSF, OtP, OtR, Strz, VVP, WaP, Wim. Also SA, Tas. Rare but widespread, usually solitary, confined to winter-wet and swampy areas, also in disturbed sites such as mown firebreaks, roadside embankments or lightly grazed plains. Flowers Oct.-Dec. (mainly Nov.). Grows in and around swamps, in soaks or besides streams in open forest, woodland, heathy woodland or heathland on moist water-retentive soils.

Flowers are self-pollinating and only open on warm, humid days.

Forming putative hybrids with Thelymitra ixioides, which are morphologically similar to T. ×truncata.

Thelymitra holmesii has been confused with T. peniculata, but the latter grows in drier habitats, generally flowers earlier and has more or less terminal white hair tufts on the lateral lobes of the column.

Source: Weber, J.Z.; Entwisle, T.J. (1994). Thelymitra. In: Walsh, N.G.; Entwisle, T.J. (eds), Flora of Victoria Vol. 2, Ferns and Allied Plants, Conifers and Monocotyledons. Inkata Press, Melbourne.
Updated by: Val Stajsic, 2018-02-16
Hero image
Distribution map
life Life
kingdom Plantae
phylum Tracheophyta
superorder Lilianae
order Asparagales
family Orchidaceae
genus Thelymitra
Higher taxa


Source: AVH (2014). Australia's Virtual Herbarium, Council of Heads of Australasian Herbaria, <>. Find Thelymitra holmesii in AVH ; Victorian Biodiversity Atlas, © The State of Victoria, Department of Environment and Primary Industries (published Dec. 2014) Find Thelymitra holmesii in Victorian Biodiversity Atlas
  Bioregion Occurrence status Establishment means
Wimmera present native
Glenelg Plain present native
Victorian Volcanic Plain present native
Gippsland Plain present native
Otway Plain present native
Warrnambool Plain present native
Goldfields present native
Central Victorian Uplands present native
Greater Grampians present native
Dundas Tablelands present native
East Gippsland Lowlands present native
Highlands-Southern Fall present native
Otway Ranges present native
Strzelecki Ranges present native

State distribution

Distribution map
Western Australia
South Australia
New South Wales
Australian Capital Territory