Stipe (botany)

Inbotany,astipeis a stalk that supports some other structure.The precise meaning is different depending on which taxonomic group is being described.

• 
  The long stipe of aHelicteresflower.
• 
  remains as each flower forms a fruit.

Hexagonal stipe bases of the fernCyathea medullaris

An orchid's stipe, with pollinia

The stipe of a brown alga

In the case offerns,the stipe is only thepetiolefrom therootstockto the beginning of theleaftissue, or lamina. The continuation of the structure within the lamina is then termed arachis.

In flowering plants, the term is often used in reference to a stalk that sometimes supports a flower'sovary.Inorchids,the stipe or caudicle is the stalk-like support of thepollinia.It is a non-viscid band or strap connecting the pollinia with the viscidium (the viscid part of therostellumor 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 thethallusof amushroomor aseaweed,and is particularly common amongbrown algaesuch as kelp. The stipe of a kelp often contains a central region of cells that, like thephloemof vascular plants, serves to transport nutrients within the alga.

See also

• Rachis
• Stipe (mycology),the stalk supporting the fruiting body of somefungi.