Colchicum questions

Jim McKenney
Fri, 03 Jun 2005 16:55:56 PDT
John Grimshaw's comments about Colchicum byzantinum have really lit a little
fire here: he has in passing commented on something which touched on a
little mystery in my garden which has baffled me for years. 

Perhaps we should call this the "other" mystery with respect to Colchicum
byzantinum. The primary mystery about this plant concerns its origin: the
plant grown under this name in the early seventeenth century cannot be our
plant: that plant set copious, large seeds. Our plant is almost certainly
not the one grown by Clusius, although there must be some very close

But here's what really interests me: I've had Colchicum byzantinum, or what
I think is C. byzantinum, in my garden for decades - the first plants were
obtained back in the '60s of the last century. However, the plants I have
now don't seem to fit exactly the description in Bowles - in particular, the
flowers are bigger than expected and have narrower segments. This has long
bothered me, and one response to this uncertainty has been to obtain
additional plants under this name now and then. 

In particular, I have purchased from local dealers (where I could see the
plants blooming dry on the shelves) plants which are well described by
John's description "broad segmented". 

Curiously, that is not the end of the story. Those "broad segmented" flowers
are soon replaced by flowers with narrower segments. This happens in the
initial year, and also in subsequent years there are typically few if any of
the broad segmented flowers. 

Why this should be has long puzzled me, and perhaps someone else has noticed
this and has a good explanation. I can think of several possible
explanations, but have no evidence to choose among them. For instance,
perhaps the form of the flower is influenced by temperature. It's a lot
warmer in Maryland in September when these plants bloom here than it is in
the UK. Presumably, it's warmer yet in Angelo's Apulia. 

Another possibility: has anyone investigated the cytology of C. byzantinum?
Is it triploid or aeuploid ("aneuploid")? I know that sometimes when a plant
has two groups of cells at different ploidy levels, one or the other of the
groups sometimes overwhelms the other. A plant that starts out as primarily
tetraploid but with some diploid cells will sometimes undergo a
transformation as the diploid cells out-compete the tetraploid cells - with
the result that the plant eventually emerges as a diploid. Perhaps something
similar is happening with Colchicum byzantinum.  

Thanks, John, for mentioning that others have observed the two different
"forms" of Colchicum byzantinum (if in fact they are two forms of the same

Jim McKenney
Montgomery County, Maryland, USA, USDA zone 7, where Angelo's plants with
their big corms and wide, narrow-segmented flowers sound a lot like my

More information about the pbs mailing list