Floatation method for germinating Rhodophiala seeds

[Piotr]

Hi everyone,

Thanks Uli! I am glad I have been able to bring some interest the the Forum. You do not have any issues with Stagonospora? Are all your Hippeastrums grown from seed? I feel like here in the UK you can not get a Hippeastrum bulb which is not affected. I actually got one this year, sold as H. vittatum, kind of an impulse buy because it reminded me of the one my granddad gave me when I was a boy, and I am pretty sure it has it too.

David maybe you know if there is a product in the UK which is effective on Stagonospora?

I do not know about those outdoor pests Uli Everything I have is grown in pots, indoors, because I do not have a garden. Fungus gnats can be a nuisance, but I use nematodes as a precaution now, whether I see any flies or not.

Yes, thank you, I had been using PBS WIKI for quite a long time before I decided to join the forum. Growning plants from seed is very rewarding, but the problem is you have to keep all those seedlings until they flower to see what you have, and I have very limited space. Also, you get attached and end up keeping too many once they have flowered

Below is a photo of the 21 seedlings I planted in a pot. It has been exactly 14 days since I floated the seeds in water.

[David Pilling]

David maybe you know if there is a product in the UK which is effective on Stagonospora?

Sorry Piotr, no idea. I've not heard of the problem before - there's a wiki page:

https://www.pacificbulbsociety.org/pbswiki/index.php/StagonosporaCurtisii

looking at the photos, I feel I have seen the disease occasionally. But not something that is trouble for me.

I'm pleased to see the photo of your floated seedlings, a lot happier picture than when you began this thread.

[Uli]

Hello Piotr,

Yes, I do see some red spotting on adult Hippeastrum bulbs but it does not seem to harm them. All of my Hippeastrum are growing outdoors, most of them in pots but if I have a lot (from seed) I try at least part of them in the open ground. Only the seedlings are kept under glass. My winters in Portugal are frost free and Hippeastrum grow in many gardens. 
Yes, most of my Hippeastrum but not all is raised from seed. 
Narcissus fly and rodents are the biggest enemy.

Your seedlings look very good! I start gently fertilizing at this stage.

[Lee Poulsen]

I wouldn't compare Rhodophiala bifida with all the other Rhodophialas. The main reason being that R. bifida is native to Argentina which has summer rainfall/drier winter pattern while all the other Rhodophialas are native to Chile which has a pronounced winter rainfall/very dry summer pattern--even though R. bifida grows during the winter and is dormant during the summer. It doesn't mind summer rains, while the Chilean Rhodophialas, depending on how far north they come from in Chile, may be killed by summer watering/rain.

However, the paper that has turned many of the these genera into merely Hippeastrum or Zephyranthes, also gave a DNA-sequenced tree of many of the species. And it was clear that definite subgenus groupings exist. To the point that the paper actually discusses whether to lump them all together into just two genuses or to give them all different genus names. So they compromised by defining subgenus names and listing all the species they sequenced that belonged in their respective subgenus.

What is interesting are a few species that formerly were placed in some of the other genera now belonging to completely different subgenera along with species that we didn't know they were sister species of.

In any case, in this overall tribe, the thing to pay attention to, in my opinion, are the subgenera. So it turns out that R. bifida is its own Zephyranthes subgenus, Neorhodophiala. Most of what used to be Chilean Rhodophialas are now Zephyranthes subgenus Myostemma (which also used to be a synonym genus name for the Chilean Rhodophialas). And a few of the Rhodophialas are not related to Zephyranthes at all, but instead to the Placeas and Phycellas.

Here is a cladogram from the DNA sequencing of the various groupings among these related species.

[Lee Poulsen]

And here is a spreadsheet I started to put together of some of the species and how they're related and how their names have been changed based on that paper and subsequent correction paper. 

(BTW, I'm, not a big fan of the amount of "lumping" they did. I thought it was a cop-out compromise they made to specify a bunch of IMO very different subgenera instead of genera. Their excuse was that by only specifying them as subgenera, since the scientific name is only the genus and species names, and not the subgenus names, they won't have to change anything as the DNA sequencing and the tree it produces becomes more refined and subsequent rearrangements of some of the branches or subgroups occur.)

[Lee Poulsen]

This is what they said about their subgenus decision:

A division into subgenera would be informative regarding relationships within each genus, notwithstanding that this subgeneric classification is open to further considerations as their phylogenetic structures are better resolved.

The refinement of the subgeneric taxonomy, however, would not require additional changes in species names (as subgeneric names are not part of the binomial).

Therefore, this scheme is likely to lead to more robust nomenclatural stability in this traditionally contentious group.