Re: SPEC-X: HOLDEN'S CHILD
- Subject: Re: [iris-talk] SPEC-X: HOLDEN'S CHILD
- From: B* S*
- Date: Thu, 21 Feb 2002 11:23:42 -0500
On 2/20/02 9:23 PM, "Randy Squires" <randysiris@juno.com> wrote:
> <hensler@povn.com> writes:
>> With a name like HOLDEN'S CHILD I'd guess it was out
>> of HOLDEN CLOUGH but would prefer to find out for certain what the
>> registration says.
>
> Christy,
> Holden's Child (S. Tiffney R '88) Wide apogon hybrid, 27" M.
> Dark red purple (RHS 83A/B) with flanges on hafts; solid stalk
> Holden Clough X self introduced '91
>
> BTW... Holden Clough (D. Patton '71) Chrysographes hybrid, 26" L.
> Yellow veined purple, giving a rich brown appearance; form resembles
> I. pseudacorus.
> I. chrysographes X I. pseudacorus.
The parentage of HOLDEN CLOUGH is hardly settled. Although the plant first
appeared in a row of chrysographes seedlings (evidently the only evidence
for that plant being a parent), the variety is very strongly I. pseudacorus
in most of its characters, and doesn't at all resemble chrysographes. While
pseudacorus crosses readily with many other members of the Laevigata
section, no other hybrids with Sibericae are known to be in existance (the
BIS species book does list hybrids with prismatica and siberica, without
comment, but curiously does not list any with chrysographes). Many
pseudoacorus hybrids are listed in the SIGNA 1999 checklist, but I did not
go through and read the entries for each one to see if any
pseudacorus/Sibiricae hybrids are still around, if they ever really existed.
HOLDEN CLOUGH has 37 chromosomes (explaining its near-sterility).
Pseudacorus has 34, and chrysographes 40. Thus a true
pseudacorus-chrysographes hybrid would be expected to have 37 (17 +20). For
a while there was concensus that the other parent was I. foetidissima, based
on plant characteristics. Foetidissima also has 40 chromosomes, and so is a
reasonable candidate on those grounds. Foetidissima is a somewhat isolated
species of uncertain relationships but it has been suggested that it is an
aberrant member of the Spuria section. Some have also suggested I.
versicolor as the other parent; versicolor has been counted at 72, 84 and
108 or 105 chromosomes, so chromosome evidence would seem to militate
against this idea. Other crosses of pseudacorus and versicolor have not
produced plants that look like HOLDEN CLOUGH.
A hypothesis that has never been put forward before, to my knowledge, is
that HOLDEN CLOUGH is a pure pseudacorus in which the violet veining of the
signal area has spread over the whole flower. If the chromosome count is
correct, one might suppose that the 3 extra chromosomes came about as a
result of a meiotically unbalanced gamete which nonetheless was functional.
This is another of those issues that probably could be resolved by DNA work,
but is unlikely to be so in the near future.
Bill Shear
Department of Biology
Hampden-Sydney College
Hampden-Sydney VA 23943
(434)223-6172
FAX (434)223-6374
email<wshear@email.hsc.edu>
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