Notes on identifying white rain lilies in Texas

I've been wanting to learn how to identify the white rain lilies, so I sat down and pulled together the identifying characteristics. I'm no expert, so offer corrections if anything is incorrect.

Visual guide:

Posted on 04 January, 2022 17:32 by pfau_tarleton pfau_tarleton


Thanks for putting this together

Posted by lappelbaum over 2 years ago

I just ran across this helpful image while trying to understand the eFloras descriptions

Posted by lappelbaum over 2 years ago
Posted by lappelbaum over 2 years ago

I don't have a good feel yet for separating some chlorosolen from traubii--there seems to be variation within chlorosolen that borders on traubii. We need to search for more characters that can support the distinction.

Posted by pfau_tarleton over 2 years ago

Wow! Great work as always!

I actually got a side-by-side comparison of Z. drummondii and Z. chlorosolen here. They happened to be growing close to each other. I was thinking of creating something like this for the rainlilies, but I'm glad to see you've already created a guide.

Also agree that chlorosolen and traubii are difficult ones—I spent some time with a few other iNatter's debating over this observation trying to figure out whether it was one of those two.

Posted by arnanthescout over 2 years ago

Neat side-by-side @arnanthescout, I added a link to it in the guide

Posted by pfau_tarleton over 2 years ago

Hmmm. I had not heard of Z. traubii, and apparently neither has BONAP, but I guess I'll have to keep an eye out.

As for Z. drummondii and chlorosolen, I usually check the location of the ovary relative to the subtending node as described in the Flora of North Central Texas. I think it is fairly reliable, though not noted in the FNA so maybe not. Unfortunately, this detail is not captured in very many photos from what I remember.

For reference:

Posted by rymcdaniel over 2 years ago

BONAP's map is here

I had originally linked to their maps, but they use the old names which would be confusing.

I'm searching for the paper that described traubii as a species--no luck yet. I did find this, though, which was interesting:
"The position of the stigmatic lobes relative to the anther is a strong indicator of a rain-lily's somatic chromosome number. A rain-lily with a well-exserted stigma with rare exception has less than 30 somatic chromosomes. If the stigma is shortly exserted (less than 3mm between the base of the stigma and the top of the anthers), or among or below the anthers, that rain-lily has more than 30 somatic chromosomes."

Posted by pfau_tarleton over 2 years ago

I don't think it's confusing. Scientific name revision happens all the time. Here's the full page for Cooperia species:

Posted by lappelbaum over 2 years ago

@lappelbaum, yes, but this genus is particularly confusing because Cooperia drummondii became Zephyranthes chlorosolen, yet there's still a drummondii. So I'm not even sure which BONAP map refers to which species in this case.

Posted by pfau_tarleton over 2 years ago

Wow, I didn't know that. If there was already a Z. drummondii and they wanted to move Cooper is drummondii to Zephyranthes then they would need a new specific epithet (i.e. chlorosolen).

Edit: there is no drummondii on the link I provided. Cooperia chlorosolen is on there.

Posted by lappelbaum over 2 years ago

Zephyranthes drumondii has 3 synonyms:

Cooperia pedunculata
Hippeastrum drummondii
Sceptranthes drummondii

Posted by lappelbaum over 2 years ago

Zephyranthes chlorosolen has 15 synonyms:

Amaryllis drummondii
Cooperia brasiliensis
Cooperia chlorosolen
Cooperia drummondiana
Cooperia drummondiana var. chlorosolen
Cooperia drummondii
Cooperia kansensis
Cooperia mexicana
Hippeastrum chlorosolen
Leucothauma chlorosolen
Zephyranthes brasiliensis
Zephyranthes brazosensis
Zephyranthes brazosensis var. chlorosolen
Zephyranthes herbertiana
Zephyranthes kansensis

Posted by lappelbaum over 2 years ago

So that means that the Cooperia pedunculata map on BONAP is the correct one for Z. drummondii. And the Cooperia chlorosolen map is the correct one for Z. chlorosolen.

Posted by lappelbaum over 2 years ago

Thanks! Very detailed and helpful to be side by side.

Posted by torresaurus over 2 years ago

And so it goes....
Thanks Russell. Appreciate your efforts. Visual guide is great. Now I must go right all my wrongs.

Posted by connlindajo over 2 years ago

just what i was looking for thanks

Posted by lanechaffin almost 2 years ago

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