The bulbs of Narcissus longispathus begin to sprout leaves and floral scapes in late February. Each individual bulb produces one scape, which bears a single, distinctive, bright yellow flower that blooms between March and late April to early May. The flower lasts for around 17 days (3) (4) (8).
The flowers of Narcissus longispathus are ‘self-compatible’, meaning that the flowers may be pollinated using pollen from the same flower, or from another flower on the same plant. More frequently, however, Narcissus longispathus is pollinated by small, solitary bees, such as Andrena bicolour, which inadvertently transfer pollen between different plants as they forage (4) (6) (8).
Narcissus longispathus develops fruits between April and May, which are usually shed by early June. The seeds are buoyant and have a thick coating, which means that while most seeds fall directly to the ground beneath the parent plant, some seeds may be dispersed by water (4). The flowers and fruits of Narcissus longispathus are often eaten by the caterpillar larvae of Trigonophora flammea, and by beetles such as Tropinota squalida (8).