Fl. 127 mm wide; perianth segments broadly ovate, blunt, prominently mucronate, deep golden yellow, spreading, somewhat creased, overlapping half; the inner segments only a little narrower, square- shouldered at base, slightly inflexed; corona funnel-shaped, strongly ribbed towards the mouth, slightly darker in tone than the perianth, with mouth expanded and frilled, rim deeply crenate.
There are no photos of "Portmarnock" in Daffseek.