Re: African irises?
- Subject: Re: African irises?
- From: i*@easynet.co.uk (Ian Black)
- Date: Tue, 5 Mar 96 15:16:59 MST
Robert Turley wrote:
>
>There seems to be some confusion concerning the the genus Moraea and Dietes.
> They would appear to be synonyms. In other words, they are the same group
>of plants with two names. According to John E. Bryan, BULBS, (Oregon
>publication) Volume 1, A-H, p. 161, "Dietes is a native to South Africa, Lord
>Howe Island, and Australia. Many authorities include this genus in Moraea
>but others separate it because the rootstock is a rhizome, not a corm as in
>Moraea. This seems to me a reasonable division and so the genus is listed
>here separately. The foliage of these plants is evergreen whereas in Moraea
>it is deciduous".
This sent me scuttling off to look in the monograph on Moraeas, which
incidentally is called "The Moraeas of Southern Africa", by Peter Goldblatt.
In the section on systematics, he writes - "The african cormous & bifacial
leaved genera of Irideae are probably derived from ancestral stock similar
to the small modern genus Dietes. that has often in the past been included
in Moraea. Dietes also has Iris-like flowers but it differs from Moraea in
its unifacial sword-shaped leaves of the basic type found in Iridaceae, and
in having a rhizome, both these features considered unspecialised. In
addition, all Dietes species are evergreen, a characteristic that is also
probably primitive. Dietes fits very well the concept of a very primitive
genus of tribe Irideae and it is probably close to the lines that give rise
to Iris in the northern hemisphere and to Moraea in Africa. Of the two,
Iris is perhaps the less specialised, since most species have a rhizome and
unifacial leaves, and technically Iris differs from Dietes in its deciduous
habit (n.b. - don't tell that to the I. foetidissima that keeps trying to
infest my garden - Ian) and in having the tepals united in a tube. Some
species of Iris are more specialised ... but the less specialized species
are closer to Dietes than to Moraea."
If true, it's interesting to consider that these plants may resemble the
fore-runners of modern Iris species.
Ian
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Ian Black Alton, Hampshire, UK - ianblack@easynet.co.uk
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