With thick, sessile leaf 20-40mm long, oblong with a short point, clasping the stem.
Sitting on a short stalk above the leaf, mostly green with a small area of blackish crimson at back of labellum throat. Flower compressed fore and aft, labellum narrow and deep, rounded to a small point which drops below the downward facing auricles. Sepals and petals project forward and outward.
August - September.
Calcareous siltstone, mudstone and limestone country; streamsides, damp seepages, roadsides. Taranaki and central North Island.
Part of the C. rivularis group. Several regional forms may be worthy of recognition as sub species. Northern forms may grade to C. rivularis according to Bruce Irwin. Within Taranaki hybridism between C. papa and C. iridescens has been seen, the most notable at Mangatote Viaduct where a very diverse range was noted in 10 m along a ditch (NZNOGJ 82:20).
Flower sits above leaf, mostly green with patchy maroon in the throat.