One of 2 basic morphologies of stele, the other being protostele. Siphonosteles are the more highly developed form, being characterized by a cylinder of xylem and phloem surrounding a pith. Siphonosteles can be subdivided into amphiphloic siphonostele and ectophloic siphonostele. Compare dictyostele and monostele.
Subjects: Plant Sciences and Forestry.