Corybas confusus Lehnebach, 2016

Lehnebach, Carlos A., Zeller, Andreas J., Frericks, Jonathan & Ritchie, Peter, 2016, Five new species of Corybas (Diurideae, Orchidaceae) endemic to New Zealand and phylogeny of the Nematoceras clade, Phytotaxa 270 (1), pp. 1-24 : 9-10

1. Corybas confusus Lehnebach , sp. nov. ( Fig. 6A–C)

Type:— NEW ZEALAND. South Island: north-west Nelson, Kahurangi National Park, Salisbury Lodge, along the Potholes track, 16 November 2011, Lehnebach, Frericks & Moorhouse SP104126 (holotype: WELT).

Diagnosis:— C. confusus resembles C. obscurus in the dark maroon colour of the labellum but differs by its dark to light green dorsal sepal with obtuse to slightly retuse apex that extends beyond the labellum. It differs from C. trilobus by its widely ovate to cordiform, distinctly mucronate leaf and dark maroon labellum.

Terrestrial herbs, 12–30 mm tall at flowering. Leaf distinctly petiolate, petiole (2.8)7.5–12.5(31.4) mm long; lamina cordiform to widely ovate, (9.7)10.8–14.1(19.0) × (10.8)13.5–17.4(21.3) mm; margin entire; apex mucronate with mucro (0.1)0.8–1.5(2.2) mm long. Flower solitary, held erect on a peduncle (0.6)2.8–4.3(7.8) mm long; floral bract triangular to widely deltoid when flattened, (1)2.6–3.9(6.6) × (1.3)1.7–2.4(3) mm; dorsal sepal dark or light green, with red-maroon streaks and blotches towards the apex, arching over the labellum, concave to cucullate, narrow at the base and spathulate towards the tip, apex obtuse or slightly retuse; lateral sepals linear-filiform, whitish or red to maroon, (13.1)19.0–27.0(46.1) mm long; petals similar to the lateral sepals but longer, (27.0)36.9–49.7(75.0) mm long; labellum dark red to maroon with a pale green to yellowish centre, auriculate at base, aperture (0.8)1.8–2.3(3.0) mm in diameter; lamina deflexed, ca. 7–10 mm wide, with a central groove formed by an inwards folding of the lamina, extending downwards almost to the lower margin and sunken pit formed at the point where the lamina bends, upper margin incurving, mostly entire but finely erose or lacinate towards the lower margin, apex notched, inner surface covered with small hairs. Ovary (3.0)4.3–6.0(7.6) mm long. Column 2.1 mm long, straight, with truncate to emarginate wings at either side of the stigma.

Specimens examined:— NORTH ISLAND: Tongariro National Park, Whakapapa, sites along Whakapapanui stream, 16 October 2012, McGlynn SP104176 ( WELT) ; Tongariro National Park, Whakapapa, sample sites along Whakapapanui stream, 22 October 2011, McGlynn SP104402 ( WELT) ; Egmont / Taranaki National Park, Stratford plateau, 30 October 2012, McGlynn SP104180 ( WELT) ; Egmont National Park, Dawson falls, on Ridge track to Wilkies pools/ Waingongoro hut, 30 October 2012, McGlynn SP104403 ( WELT). SOUTH ISLAND: Kahurangi National Park , at the intersection of Gordons Pyramid route and Potholes track, 16 November 2011, Lehnebach, Frericks & Moorhouse SP104397 ( WELT). Kahurangi National Park , along Gordons Pyramid route, 16 November 2011, Lehnebach, Frericks & Moorhouse SP104398 ( WELT) ; Kahurangi National Park, along Potholes track, close to Sphinx Valley cave , 16 November 2011, Lehnebach, Frericks & Moorhouse SP104399 ( WELT) ; Arthur‘s Pass National Park, at the end of Otira Valley track, 12 December 2011, Lehnebach & Zeller SP104143 ( WELT) ; Arthur‘s Pass National Park, Kellys Creek, Carrol‘s hut track, 11 December 2011, Lehnebach & Zeller SP104400 ( WELT) ; Arthur‘s Pass National Park, Otira Valley , 12 December 2011, Lehnebach & Zeller SP104401 ( WELT) .

Distribution:— Endemic to NZ, both North and South Islands ( Fig. 6D). It may also be present in the Chatham Islands, but further study of fresh fertile material is needed to confirm its presence there.

Habitat:— Found in leaf litter under southern beech [ Fuscospora Heenan & Smissen (R.S.Hill & J.Read) (2013: 12–13) or Lophozonia Turczaninow (1858: 396) , Nothofagaceae ] forest, scrub or tussock in subalpine habitats, damp mossy subalpine open areas, 1000–1100 m.

Phenology:— Flowering October to early December; fruiting November to January.

Etymology:— The epithet confusus is a reference to the similarity between the flowers of C. confusus and C. obscurus and leaf shape to those of C. macranthus and C. orbiculatus .

Conservation status:— Corybas confusus is common in montane, sub-alpine and alpine areas of the North and South Islands. It is, therefore, regarded as ‘Not Threatened’ using the criteria of Townsend et al. (2008).