vascular bundle

[Peter Stevens]

>It is an open question whether gametophytes have vascular tissue - 
>probably not, but...

Vascular bundles in levaes usually do not have cambium, they are 
closed (no cambium develops); when vascular bundles develop in the 
stem of broad-leaved angiosperms, they often/usually have cambium 
(such vascular bundles are called "open"), but not all broad-leaved 
angiosperms have separate and recognisable vascular bundles; in 
monocots and things like Ranunculaceae the cauline vasular bundles 
are also closed.

P.

>The purpose for asking this term was, that they are present in all 
>kinds of organs and not just limited to the leaves.
>
>In leaves mid veins are representing the vasculature and the leaf VB 
>is a part of that network of vasculature and as Dave pointed out 
>there are many other parts as well.
>
>My suggestion is to include this term. If agreed, the other question 
>would be, where should we place it, it's not just a tissue, but 
>contains a lot of tissue types. Thus it is an organized structure or 
>a region in an organ.
>
>The proposed structure is
>i = instance of
>p = part of
>
>
>Sporophyte
>--p--vascular bundle
>-----i--leaf VB
>-----i--stem VB
>-----i--root VB
>-----i--stamen VB
>-----p--xylem
>-----p--phloem
>-----p--cambium
>--p--shoot
>-----p--stem
>--------p--stem VB
>-----p--leaf
>--------p--root VB
>--p--root
>-----p--root VB
>
>I am not sure....
>
>#1
>Its true that that the three terms xylem, phloem and cambium are not 
>always part of VB.
>
>But as we know the PART of relationship we have suggests that, a 
>child is a partof but not always a partof parent term. Thus this 
>lineage seems correct.
>
>#2
>Do gametophytes also have VB?
>
>
>
>Suggested definitions for VB are
>
>by Fahn: A strand of conducting tissue
>
>By Essau: A strand like part of the vascular system composed of 
>xylem and phloem. occurs in stem, leaf and flower.
>
>By Dickison: A strand like association of primary xylem and phloem 
>that extends throughout the plant body.
>
>http://www.cogsci.princeton.edu/cgi-bin/webwn?stage=1&word=vascular+bundle
>a unit strand of the vascular system in stems and leaves of higher 
>plants consisting essentially of xylem and phloem
>
>
>
>If that is an accepted structure then we may need a further 
>instantiation of the terms xylem, phloem and cambium, because as of 
>now these are the generic terms. But that is a topic for another 
>request to be sent on the mailing list.
>
>
>Thanks
>Pankaj
>
>
>
>
>Anuradha Pujar wrote:
>
>>
>>Hello,
>>
>>These are just a couple of references, please have a look.
>>
>>
>>http://www.plantphysiol.org/cgi/content/full/129/3/1019
>>
>>http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14630956
>>
>>http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15258165
>>http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14614507
>>http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12615934
>>http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=2102372
>>
>>anu
>>
>
>--
>************************
>Pankaj Jaiswal, PhD
>G15-Bradfield Hall
>Dept. of Plant Breeding
>Cornell University
>Ithaca, NY-14853, USA
>
>Tel: +1-607-255-3103
>      +1-607-255-4109
>Fax: +1-607-255-6683
>http://www.gramene.org
>************************