In article , Chris Boulby
writes
Why can't you manually pollinate the plants to get seeds?

Thats a good question. I've tried but somehow they don't work on the
same plant or clones. I'd need another strain to have any hope of so
doing, and I've few plants where I have had different sources. Almost
all the material that I have was brought back by Hilliard & Burtt, two
botanists from Edinburgh who revised the genus in the 1980s. So, I'm
stuck. And the plants are a bit endangered in the wild now too, some
are on the red list in fact. I worry about this a lot.

The obvious explanation for your problems with seed set is that Diascia
is self-incompatible. I've found a web site (just the one) that states
that this is the case.

The usual explanation given for plants deteriorating after generations
of vegetative propagation is a build up of viral load. For reasons not
obvious to me, micropropagation (sometimes?) clears this up.

An alternative to obtaining seed is to exchange cuttings with other
growers - in the hope that they have a different clone. Ness Botanic
Gardens on the Wirral have quite a few Diascias, but I think they're all
hybrids. Sunningdale in Gloucestershire, according to the web, have a
least a couple of species.


--
Stewart Robert Hinsley