We have not personally grown this rather new introduction from China. Our photos and cultural information have been provided by our friend Rizanino (Riz) Reyes.
From Western China, this is a late August / early September here in the Pacific Northwest. Bulbs like a rich, moist, but well drained planting site. The blooms are strongly recurved and down facing. Color is a deep cantaloupe orange usually with green but sometimes black nectarines. The late Ed McRae was working with this species towards producing his “black heart” Aurelian hybrids. Often confused with L. henryi, L. rosthornii has extremely long filaments. Riz reports that it has a light "gentle" fragrance.
Photos contributed by Riz Reyes.