Does anyone want tetraploid? acicularis X (Hansa X OP) seeds?

Again, too many have germinated. Same prodedure as the last “anyone want” posting.

So far, no one has asked for this one. I got 10 more germinations today.

What could it be used for? From the way Hansa has behaved for me, I suspect that it gives off at least some 28 chromosome pollen. For example this year I had 2 sucessful pollinations on my tetraploid acicularis:

2 hips of (Tetraploid Acicularis X OP) X (Hansa X OP)


3 hips of (Tetraploid Acicularis X OP) X R-15

As a mother (Hansa X OP) gave the following hips:

1 hip of (Hansa X OP) X Dortman


1 hip of (Hansa X OP) X Tetraploid? Acicularis

You could get a very hardy tetraploid with mixed blood. The mixed blood I feel is important as I think mixed blood, mainly species parents are more likely to be fertile with a wide range of roses (if fertile at all) than pure species and allow more of the desirable characteristics of the other parent to express themselves. (I think pure species roses tend to dominate in the first generation when mated with modern roses).

Henry, have you performed controlled crosses that suggest this acicularis is tetraploid? For instance, is its pollen easily accepted by other tetraploids? The crosses you listed here sound good but could also be consistent with it being a diploid, although a diploid hybrid with a Hansa seedling would certainly be nice as well. I’m curious partly because the acicularis-like wild species around here appears to be a diploid, too.

Stefan, my last summers crosses are arranged by pollen parent at:


And by seed parent at:


3 hips of (Tetraploid? Acicularis X OP) X R-15

2 hips of (Tetraploid? Acicularis X OP) X (Hansa X OP)

1 hip of ((Delicata X OP) X ((Therese Bugnet X OP) X OP)) X Tetraploid? Acicularis

1 hip of (Hansa X OP) X Tetraploid? Acicularis

1 hip of (Calcocarpa X R. Nutkana) X Tetraploid? Acicularis

1 hip of (Corylus X OP) X Tetraploid? Acicularis

1 hip of (Calcocarpa X R. Nutkana) X (Agnes + (Tetraploid? Acicularis X OP) mixed pollen)

R-15 and (Calcocarpa X R. Nutkana) are “expected” tetraploids.

I am pretty sure that ((Delicata X OP) X ((Therese Bugnet X OP) X OP)) is a tetraploid (see what it mated with in the links above). I also think that my (Sir Thomas Lipton X OP) is tetraploid.

A comparison picture is given at:

Each spring I place a chromosome doubling compound on the first buds of various diploids and triploids in my garden see:

This past summer I had one acicularis plant that had one branch that had flowers that looked like the tetraploid? Acicularis plant while the rest of the branches had flowers that looked like the diploid form.

Out of curiosity, what are the major differences between the diploid form and the tetraploid form?

I will be planting r. acicularis plant spring and I am curious what the the ploidy will be.

The diploid form is native to Japan, Rosa acicularis var. nipponensis. According to Modern Roses 11 nipponensis has also been found by others to exist in the tetraploid form.

I am not aware of anyone specifically characterizing the tetraploid form.

My pictures mentioned earlier show the main differences that I have found.

It is my impression that the U.S., Canadian forms are normally 42 or 56 chromosomes.

I obtained the Morden Rosa acicularis 4n that they have in their collection but didn’t see anything special about it. On the other hand, I have a Rosa acicularis selection that may be a hybrid with Rosa woodsii and therefore a tetraploid. It appeared in a population of mostly Rosa woodsii and the hips are round rather than pyriform shaped, which suggests that it may be a hybrid. As well, this genotype has large, attractive foliage. It’s something to look at it and be reminded of HT foliage! I intend to register it as Rosa acicularis ‘Skinneri’.