Himantoglossum robertianum is a bulbous plant. It flowers from January to April. The bulb is edible when cooked.
When the flower is fertilized by a suitable pollinator (eg. Bomblus spp.), the perianth parts shrivel and drop while the inferior ovary enlarges with the developing seeds forming an elongated, ovate fruit capsule which have bulging longitudinal ridges. The bract remains covering partially the ovary. When ripe, the fruit capsule opens up and releases the thousands of tiny and light seeds, which can be dispersed away by wind. Success of seed germination is very low, as in many Orchids.