Caladenia cardiochila
Tate Thick-lip Spider-orchidFlowering plant 10–30 cm tall. Leaf 6–10 cm long, 3–8 mm wide, sometimes dotted red at base. Flowers 1 or 2; perianth segments 1.7–2.5 cm long, yellowish green with red stripes, sometimes wholly reddish; dorsal sepal c. 3 mm wide, erect or recurved; lateral sepals 3–5 mm wide, deflexed, hardly divergent and sometimes crossing, asymmetrically lanceolate, sometimes abruptly acuminate; petals c. 2 mm wide, spreading to deflexed, similar to sepals but narrower. Labellum curved forwards, cordate or broadly ovate, 3-lobed, 9–12 mm long and 8–10 mm wide (when flattened), yellowish-green with red markings (mostly on margins, veins and mid-lobe), lateral lobes more or less flat or curved slightly upwards, tip deflexed or slightly decurved; margins thickened and dark brown around mid-lobe, more or less entire; lamina calli in 2 or 4 crowded rows not or hardly extending onto mid-lobe (usually occupying less than two-thirds of labellum and finishing more than 3 mm from tip), stout and club-shaped, fleshy, dark-coloured. Flowers Sep.–Nov.
LoM, MuM, Wim, GleP, VVP, GipP, OtP, Gold, GGr, DunT. Also SA, NSW, Tas. Apparently confined to western Victoria from near-coastal heathy woodlands to mallee scrubs on well-drained sandy soils. Mapped records from eastern Victoria are the result of misidentification of the similar Caladenia tessellata.
Caladenia tessellata is similar to C. cardiochila but differs in having generally smaller flowers with the margins of the lateral lobes of the labellum conspicuously toothed towards the mid-lobe, and 2 of the 4–6 rows of lamina calli extending to within 1–2 mm of the labellum apex. The lateral lobes of C. cardiochila are usually entire, while the lamina calli are mostly congested in a band towards the base of the labellum and never extend to within 3 mm of the labellum apex. Clinal variation may indicate incomplete speciation of these two taxa or hybridization.
Caladenia cardiochila hybridizes with C. venusta and C. lowanensis yielding flowers with a similar morphology to C. ×variabilis.
Entwisle, T.J. (1994). Orchidaceae. In: Walsh, N.G.; Entwisle, T.J., Flora of Victoria Vol. 2, Ferns and Allied Plants, Conifers and Monocotyledons, pp. 740–901. Inkata Press, Melbourne.