The long stipe of a Helicteres flower ...
In flowering plants, the term is often used in reference to a stalk that sometimes supports a flower's ovary. In orchids, the stipe or caudicle is the stalk-like support of the pollinia. It is a non-viscid band or strap connecting the pollinia with the viscidium (the viscid part of the rostellum or beak).
A stipe is also a structure found in organisms that are studied by botanists but that are no longer classified as plants. It may be the stem-like part of the thallus of a mushroom or a seaweed, and is particularly common among brown algae such as kelp. The stipe of a kelp often contains a central region of cells that, like the phloem of vascular plants, serves to transport nutrients within the alga.