Prunella laciniata germination

[Jane Hendrix]

I bought one Prunella laciniata plant from a garden center in 1997.  It is an attractive, low-growing, conservatively-spreading xeric species in my experimental garden at 10,000 feet (see photo).  Its foliage is deeply incised and an attractive gray-green in color.  The plant is very floriferous, displaying somewhat reddish-violet-hued blossoms set off against dark-red bracts.  Even after the flowers fade, the gray-green leaves and dark-red bracts persist into winter, giving extended color to that area of my garden.

I would like to share this lovely plant with others through seeds.  I have collected a large supply but so far have been unable to germinate a single seed.  Does anyone have experience germinating this particular species of Prunella?  I have germinated Prunella x grandiflora in 3 separate colors (Jelitto seeds) with no trouble at all.  Does Prunella laciniata need stratification?

[RickR]

No definitive answer here, but both the Kootenay Ag Society and the Ontario RG sites, suggest that a short? cold treatment may be needed if germination does not occur at warm temps.   ORGS suggests seed viability is short, and to sow immediately.  (I realize you have probably already seen these. )

[cohan]

I checked Gardens North, since I remembered this was in the current catalogue, and Kristl says it is an easy warm germinator; however, the plant she has listed has white flowers- I did google a bit before, but forget if there is natural colour variation...

[Jane Hendrix]

Since I have only one specimen of this species, is it possible that the seed it produces is not viable?  Before I began collecting the seed (about 4 years ago), I just let it do its "natural" thing.  I have never found a single self-sowed seedling.

[RickR]

It seems that in general, the family Lamiaceae is self fertile, but tends to rely on floral structure to encourage cross pollination.  But there are exceptions.  This gets kinda interesting.  I don't have time to read all of this but I found this paragraph here
http://chestofbooks.com/flora-plants/flowers/Wild-Flowers-Insects/Labiatae-Continued.html#.UPhXHFKnLBI

Prunella vulgaris also has the two kinds of individuals, but the female plants are comparatively rare. Axell says that, in the absence of insects, the larger flowers fertilise themselves, but this was not the case with those observed by Muller. If Prunella be really self-fertile this would constitute an argument against Muller's view of the origin of the small female flowers.

Perhaps more reading can shed some light.