On 13 Apr 07, at 1:25, DaveKarn@aol.com wrote:

A possible explanation is implicit in what follows:

I have the tetramerous form of the bright yellow "Beauverdia
sellowiana", aka "Ipheion sellowianum", now considered (iirc)
Nothoscordum sellowianum. As this also came to me from Don Elick, now
many years ago, I value it greatly. I have always kept it out of
doors with only slight winter protection, at best a covered coldframe.

One winter ten or fifteen years ago, we had a serious cold spell, as
we sometimes get thanks to outflows through river valleys of icy
Arctic air from the interior of the continent. My poor Beauverdia/
Ipheion/Nothoscordum got caught in it and froze quite solid. [Memory
fails me, but I think I either had forgotten to cover the coldframe
or had left the pot simply sitting out in the open, possibly with
overhead protection from rain.]

The plant stopped growing. For some years, every spring I would unpot
it and examine the tubers. The larger ones (size of a garden pea)
remained sound, while the smaller ones gradually disappeared. But
there was no active growth whatsoever.

No foliage, no root development, year after year. As everyone reading
can imagine, despair reigned, as the bulbs were irreplaceable.

Somewhere on the internet, I ran across a mention of the importance
of warmth to South American amaryllids and decided to experiment. I
had nothing to lose the way things were going with fewer bulbs left
every year. I took the pot into the house and put it by a large south-
facing window where it would bake in full sun nearly all day long and
the soil would warm up much more than outside. (Remember that we have
quite cool summers here -- air temperature over 70F is unusual and
cause for the population shedding all the clothes the law allows, or
even more.)

The experiment was a success and the Beauverdia/Ipheion/Nothoscordum
started to grow actively. Ever since I have been careful to give it
winter protection from sub-freezing temperatures and it remains
actively alive, though it doesn't flower all that often.

I speculate (emphasis on *speculate*) that this plant is native to a
fairly warm climate, that when exposed to serious cold it goes
dormant and the dormancy can only be broken by exposure to warmth --
70F being insufficient.

A patch of a wild ipheion (or relative!) that goes dormant for a
season then returns in full vigor after a year below ground may
simply be reacting to a spell of unusually cold weather in a normally-
warm climate.

One infers that the native habitat, though warm, has infrequent
spells of much colder weather than normal, and this behavior is an
evolutionary adaptation allowing survival through short periods
(several years even) of lower temperatures than normal.

I await comments from Alberto Castillo on the subject.