Fls 2 per stem, 75mm wide, facing upwards; perianth segments 30mm long, very broadly ovate, blunt, mucronate, greenish white 157D, spreading to somewhat reflexed, plane or a little concave, with margins incurling, with midrib showing, of membranaceous to heavy substance, overlapping half; the inner segments narrower, shouldered at base; corona 20mm long, cup-shaped, angled, greenish white 157D, with green (151C) at base, mouth expanded, ribbed and wavy, with rim crenate and narrowly flanged. Strongly scented. Mid-season.

Named in honor of Elvin McDonald, former director of Friends of the Des Moines (Iowa) Botanical Garden.