Chionodoxa was distinguished from the genus Scilla by two features: the tepals are joined at their bases to form a tube rather than being free; and the stamens have flattened stalks (filaments), which look almost like a cup in the centre of the flower.
The key difference between Chionodoxa and Scilla lies in their floral structures. Specifically, Chionodoxa's tepals are fused together to form a tube, while those of Scilla remain separate. This is further highlighted by the flattened stamen stalks in Chionodoxa, which resemble a small cup.