Re: SPEC: Gerald Darby
> I wonder if anyone has examined the origin of the dark purple stems of
> this cultivar and related plants like X Robusta "Beetroot".
I found a couple of wild I.virginica var. schrevei with distinctive purple
on the lower half of the foliage and, later, the bloom stalk. We posted a
query to the list after finding the first. My impression is that there are
genetic and environmental factors involved. The plants with the most
distinctive purple foliage were found in deeper water and were growing in a
floating mass of assorted wetland vegetation. Adjacent plants were all
green. After moving a purple plant to the garden, the color has persisted
but is not quite as distinct on the newer leaves. Still something of a
mystery, but I think it is safe to say that I.virginica may contribute to
the dark foliage.
Coastal South Carolina, zone 8b