Fl. forming a double triangle, 95mm wide; perianth segments 37mm wide, ovate, blunt, pale lemon yellow, spreading, plane or with margins incurling, smooth and of heavy substance; the inner segments narrower; corona 10mm wide, cup-shaped, ribbed, white, mouth straight and wavy, with rim crenate.
Named for a river in Belize.
There are no photos of "Sibun" in Daffseek.