It is nearly orbicular, or reniform, and 1-5 cm.
"Studies of American Fungi. Mushrooms, Edible, Poisonous, etc."
George Francis Atkinson
Calyx superior, with 5 small teeth and a deciduous cover composed of many orbicular pieces joined below.
"The Medicinal Plants of the Philippines"
T. H. Pardo de Tavera
Corolla, 4 petals, orbicular, thick, fleshy.
"The Medicinal Plants of the Philippines"
T. H. Pardo de Tavera