Galanthus leaves (vernation). In the era of molecular phylogenetics this characteristic has been shown to be unreliable and now seven moleculary defined clades are recognised corresponding to the biogeographical distribution of species. New species continue to be discovered. Most species flower in winter, before the vernal equinox (20 or 21 March in the Northern Hemisphere), but some flower in early spring and late autumn. Snowdrops are sometimes confused with the two related genera within the tribe Galantheae, snowflakes "Leucojum" and "Acis". All species of "Galanthus" are perennial petaloid herbaceous bulbous (growing from bulbs) monocot plants. The genus is characterised by the
Galanthus nivalis (flowering stalk), which bears at the top a pair of bract-like spathe valves joined by a papery membrane. From between them emerges a solitary, pendulous, bell-shaped white flower, held on a slender pedicel. The flower consists of six tepals, also referred to as segments. The outer three are larger and more convex than the inner ones. The inner flower segments are usually marked on their outer surface with a green or greenish-yellow V- or U-shaped mark (sometimes described as "bridge-shaped") over the small sinus (notch) at the tip of each tepal. The inner surface has a faint green mark covering