Fl. forming a double triangle, 120 mm wide; perianth segments broadly ovate, shouldered at base, blunt, only slightly mucronate, brilliant greenish yellow, with greenish white at base, spreading, plane, with midrib showing, of heavy substance, overlapping half; the inner segments narrower and a little inflexed; corona funnel-shaped, lightly ribbed, creamy white, with brilliant greenish yellow at rim, mouth expanded and even, with rim notched and dentate.