2009年11月12日木曜日

snow drop

All species of Galanthus are perennial, herbaceous plants which grow from bulbs. Each bulb generally produces just two or three linear leaves and an erect, leafless scape (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 has no petals: it consists of six tepals, the outer three being larger and more convex than the inner series. The six anthers open by pores or short slits. The ovary is three-celled, ripening into a three-celled capsule. Each whitish seed has a small, fleshy tail (elaiosome) containing substances attractive to ants which distribute the seeds.[6] The leaves die back a few weeks after the flowers have faded.

The inner flower segments are usually marked with a green, or greenish-yellow, bridge-shaped mark over the small "sinus" (notch) at the tip of each tepal.

An important feature which helps to distinguish between species (and to help to determine the parentage of hybrids) is their "vernation" (the arrangement of the emerging leaves relative to each other). This can be "applanate", "supervolute" or "explicative". In applanate vernation the two leaf blades are pressed flat to each other within the bud and as they emerge; explicative leaves are also pressed flat against each other, but the edges of the leaves are folded back or sometimes rolled; in supervolute plants one leaf is tightly clasped around the other within the bud and generally remains at the point where the leaves emerge from the soil.[7

]Galanthus is a small genus of about 20 species in the family Amaryllidaceae commonly known asSnowdrops. They are among the first bulbs to bloom in spring, although certain species flower in late autumn and winter.

Snowdrops are sometimes confused with their relatives, snowflakes, which are Leucojum and Acisspecies; see below.


File:Galanthus nivalis.jpg



0 件のコメント:

コメントを投稿