On 27/09/16 18:31, Spider wrote:
On 27/09/2016 16:59, Jeff Layman wrote:
On 26/09/16 18:59, Nick Maclaren wrote:
In article , Stewart Robert Hinsley
wrote:

The obvious explanation is that the parent plant is heterozyous
for stem anthocyanin (or other pigment, but google provides a
citation for the presence of anthocyanins in Amsonia)
production, and a proportion of the seedlings are homozygotes
for the recessive allele. Perhaps you'll later find a
pleiotropic effect on flower colour.

For every complex problem there is an answer that is clear,
simple, and wrong :-) That may be the explanation, but it may
well be mistaken. If the flower colours are different according
to the stem colour, I agree that would make this fairly certain.

The expected mean ratio of offspring from a self-pollinated
diploid dominant/recessive heterozygote is 3:1. 50:10 isn't
that far off 45:15 - you'd need someone with more current
statistical expertise to say whether the difference is
statistically significant for a sample of that size.

Current, I can't do, but I don't need it. That is the mean
ratio ONLY if it is a single, Mendelian gene AND the parent
reproduces purely by haploid/diploid self-pollination. In my
previous post, I missed that it was a single parent, so said
something irrelevant. I agree that is the simplest plausible
explanation. Anyway, as I said, 50:10 isn't significantly
different from 45:15.

I'm sorry to say I have been wasting your time. The plant I have
is *not* Amsonia hubrichtii (although that's what it said on the
seed packet). It has a number of almost ripe seeds heads and I
thought I'd have a look at them today. It was then that I examined
the leaves - they are lanceolate, glabrous under a x10 lens, and
around 16 cm long and 5 wide. The stems are over a metre long. That
probably makes it A. tabernaemontana, a cultivar of it, or possibly
a hybrid.

It will be interesting to see if the flowers vary between the green
and pink-stemmed plants.



I have grown Amsonia tabernaemontana in the past, though not from
seed.

Having googled for images, I am finding that pics of A.t. have green
stems. However, pics of A.t. var 'Salicifolia' show brownish purple
stems. I wonder if what you are seeing is your A.t. showing signs
of the colouring that created A.t. var. 'Salicifolia'?

Do let us know how the seedlings develop, please.

This is from Rick Darke's article in The Plantsman (June 2005).
Amsonia tabernaemontana var. salicifolia:
This variety differs from the typical species in its narrower,
consistently lanceolate, glabrous leaves giving it a willow-like appearance.

Of Amsonia tabernaemontana itself, he notes "The lanceolate to broadly
elliptic leaves are typically 7.5–10cm long, up to 2.5cm wide and often
finely hairy beneath.

My plant's leaves are up to 5 cm wide.

As far as I remember, my plant took quite a few years to flower from
seed, but I'll keep and eye on it.

--

Jeff