Nick Maclaren wrote:

| Could it be Ipomoea indica? ............

Nope. They are almost always dark blue, and little larger than a
common morning glory.

Ipomoea indica (formerly I. learii) flowers open an intense blue
taking on purplish tones after a few hours before becoming pinkish as
they fade. It's a perennial species with 10cms. wide flowers that
does not seem to set seed in this country at least and has to be
propagated by cuttings. I grow it outside, where it runs about for
7m. or more each year. I've noticed that under glass in more equable
temperatures, the blue coloration remains purer for longer with fewer
pinkish-purple tones. It would seem that the intensity of the blue is
temperature-dependent - the last flowers opening in December are
always pink with only the slightest hint of blue.

As to the plants Janet saw at Waterperrys, it's a fair bet they were
Japanese bred, Ipomoea nil variants. For many years, the Japanese
have been working on a very wide range of colour forms and flower
sizes with some producing flowers that expand to rather more than
15cms. across. The problem with these more spectacular forms is that
they really need to be grown under glass in this country if the
maximum flower sizes and best colours are to be achieved. In a mainly
hot summers like last year they do well, but in cool or wet summers
their performance compared to 'Heavenly Blue' is often very poor.
Which is why they are not more widely seen in the UK.

Some friends who live in Florida usually grow a few from seed that
they get direct from Japan. I've seen photos of them in the past and
some of the flowers are almost too large. I've been trying to get in
touch with them, but they seem to be away at the moment. I'll try and
get a source address for you if you like,