According to Thad Howard in his book, Bulbs for Warm Climates, Rigidella is a genus of bulbs from Mexico and Guatemala and are allied to Tigridia and can be hybridized with T. pavonia. The flowers either open in the morning or afternoon, closing at night. They are hummingbird pollinated, and thrive in cultivation in zones 8-10 if summers are cool. They also do well in zones 5-7 if dug and stored in winter. They do not do well where summers are hot and dry. R. flammea grows on cliffs and ledges in the state of Michoacan in Mexico. It's a robust species with flowers opening in the afternoon and closing at sunset. Flowers are scarlet with the interior spotted purplish against a yellow background. Leaves appear after flowering. It is a high-elevation plant that needs cool alpine conditions. Hope this helps. Marilyn Pekasky