This grower is sure of this plant identification.
autumn flowering snowdrop
Autumn snowdrop, Snowdrop
Galanthus reginae-olgae (Autumn snowdrop). This species is a perennial herb, the leaves are linear and grey-green. The flowers are single and will produce blooms of white-green in the autumn.
You can grow in humus-rich well-drained soil.
Grown for their pendant flowers, one on each slender stem between 2 basal leaves.