Stipule

The stipules ( stipules or stipules ) are leaf-like outgrowths of the leaf ground of many plant species, ie the lowermost part of a foliage leaf, to which it is attached to the stalk. They are an important determining feature. Some plant families lacking stipules.

In the dicotyledons, the stipules right and left of the sheet substrate always come in pairs, before. On the right picture you can see a piece of the dog rose (Rosa canina ), in which the two stipules are fused with the leaf axis. In the monocots, the stipules are seemingly leaf axils. In the grasses they are designed as small cuticle ( ligule ) at the upper end of the leaf sheath.

The stipules may be formed very different:

• In some leguminous plants ( Fabaceae, Order Fabales ), the stipules about the shape of the normal leaflets, or, as in the tendrils pea ( Lathyrus aphaca ) they take on the photosynthetic function of the leaves, as the leaf blade is transformed into tendrils.
• In the black locust (Robinia pseudoacacia), the stipules are converted into thorns.
• In most Rötegewächsen and Cunoniaceae the stipules of adjacent sheets are fused into a single entity in against or quirlständiger leaf position, in this case one uses the term Interpetiolarstipeln. In some Rötegewächsen this can also be fused together to form a sheath-like structure, so that one speaks of Intrapetiolarstipeln.
• The Knöterichgewächsen the side sheets to a membranous sheath ( Ochrea ) are fused, which includes the stems.
• For most native to Europe Rötegewächsen the stipules have the same shape as the constant against leaves, which Scheinquirle arise.