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Related to protostele: eustele, siphonostele


 (prō′tə-stēl′, prō′tə-stē′lē)
n. Botany
A stele that forms a solid core of xylem encased by phloem.

pro′to·ste′lic (-stē′lĭk) adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(ˈprəʊtəˌstiːl; -ˌstiːlɪ)
(Botany) a simple type of stele with a central core of xylem surrounded by a cylinder of phloem: occurs in most roots and the stems of ferns, etc
ˌprotoˈstelic adj
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˈproʊ təˌstil, -ˌsti li)

the solid stele of most plant roots, having a central core of xylem enclosed by phloem.
pro`to•ste′lic, adj.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
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References in periodicals archive ?
The anatomy was simple, the central strand of sclerenchyma of the algal progenitors becoming a strand of tracheids forming the earliest type of stele, the protostele. The predecessors of sieve tubes were elongated parenchymatous cells which differentiated around the central strand.
It is doubtful whether the terminology used to describe the Matteuccia apex would be as appropriate in analyzing structurally similar shoot apices of ferns with protosteles or ferns with highly dissected or polycyclic steles.