Thelymitra holmesii
Nicholls Slender Blue Swamp Sun-orchidFlowering 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.
LoM, Wim, GleP, VVP, GipP, OtP, WaP, Gold, CVU, GGr, DunT, EGL, EGU, WPro, HSF, OtR, Strz, VAlp. 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.
Weber, J.Z.; Entwisle, T.J. (1994). Thelymitra. In: Walsh, N.G.; Entwisle, T.J., Flora of Victoria Vol. 2, Ferns and Allied Plants, Conifers and Monocotyledons, pp. 840–854. Inkata Press, Melbourne.