Re:Purple-Based Foliage
- To: Multiple recipients of list <i*@rt66.com>
- Subject: Re:Purple-Based Foliage
- From: I*@worldnet.att.net (IrisFan)
- Date: Wed, 8 Jan 1997 18:46:20 -0700 (MST)
Yaaarrrgh! We are charging off on this before I mounted my soapbox and
declaimed. I have been temporarily embarrassed by my Internet provider and
didn't get a chance to plug one of my favorite subjects.
That purple based foliage confers a survival/reproductive advantage is
nearly a given. Years of anecdotal evidence is overwhelmingly in support of
this conclusion.
I believe we are missing the boat when we assume that the advantage lays in
hardiness/cold hardiness. There is a 'survival' advantage conferred by the
purple pigmentation versus lack of this pigmentation, however, this
advantage has only a secondary linkage to temperature.
My theory of the function of purple iris foliage pigmentation has not been
tested. It would not be difficult to do and would be an excellent subject
for a dissertation.
I theorize that the purple pigment is a weak bacteriostat/fungicide.
In support:
The pigmentation occurs at the point of maximum pathogen attack -- the leaf
fan--rhizome junction.
Rapid plant growth induces tears in the leaf base where it joins the
rhizome. The tears provide an entry point for pathogens carried in by rain
induced soil splash. These tears occur in the purple pigment zone. The
pigmentation reduces the viability or eliminates the pathogens.
Rot, both fungal and bacterial is a less frequent occurrence in iris
cultivars that have purple leaf bases.
The iris-l survey moderated and collated by Sharon should show if an
advantage does, in fact, accrue to purple pigment cultivars.
Kitchen table chemistry (at the most a Com. college chem lab) should
conclusively show whether the purple iris pigmentation exhibits activity.
Any takers?
