Iris setosa and Iris hookeri

[ashley]

Thanks for these photos Gabriela.  For slow learners like me could you please elaborate on the key differences?
I admired them greatly in Newfoundland and southern Labrador but never got around to differentiating reliably

[Maggi Young]

I would like to clarify because it was mentioned here and not for the first time - the case of Iris setosa, which is different from Iris hookeri (syn. Iris setosa var. canadensis for those who don't accept I. hookeri).
These NA Irises are mixed up in the trades, seedex, etc.... to the point of no return probably. Certainly not using the proper names has contributed to this situation. They are distinct though:

Iris setosa




Iris hookeri

[Rick R.]

I am a bit confused now, also.  I grew this from wild Iris setosa seed from the Kenai pennisula, Alaska.

[Gabriela]

Thanks for these photos Gabriela.  For slow learners like me could you please elaborate on the key differences?
I admired them greatly in Newfoundland and southern Labrador but never got around to differentiating reliably

I'm  slow learner as well when it comes to irises Ashley. In all fairness, only the fact I provide seeds made me to look more into this.

It is very probably that you admired Iris hookeri - when not in flower is not very easy to tell apart, but there are differences:
see in Flora of North America
http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242101705

When in flower - 1-2 flowers/stem (I. setosa 2-3) and  petals "much reduced to insignificant, involute or tubular rudiments, 1–2 cm, apex with short bristle".
There are other details as well, true that my pictures don't show enough.

[Gabriela]

I am a bit confused now, also.  I grew this from wild Iris setosa seed from the Kenai pennisula, Alaska.

Yours, if only after the distribution is I. setosa Rick and of course the fruiting stems with the "usually 2 flowers/stem". As well, there are many other details which can't be observed in a picture.

My picture with I. setosa is a cultivated form, and normal to differ from yours which is from wild accession.

[ashley]

It is very probably that you admired Iris hookeri - when not in flower is not very easy to tell apart, but there are differences:
see in Flora of North America
http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242101705

When in flower - 1-2 flowers/stem (I. setosa 2-3) and  petals "much reduced to insignificant, involute or tubular rudiments, 1–2 cm, apex with short bristle".
There are other details as well, true that my pictures don't show enough.

Thanks Gabriela.  Yes it seems that I. hookeri is widespread both in Newfoundland & southern Labrador, especially in coastal areas.

[ashley]

However is this Iris setosa, growing near St. Johns?   I. versicolor?

[Karaba]

Could the last one be Iris versicolor ?

[ashley]

Perhaps so Yvain, because the Digital Flora of Newfoundland & Labrador Vascular Plants doesn't list I. setosa at all (apart from var. canadensis as a synonym for I. hookeri). 
However without knowing the origin I'm still unclear how to distinguish reliably between hookeri & setosa.  For example, reply#5 above shows I. hookeri mostly with branched stems, inconsistent with the Flora of North America description

[Lesley Cox]

In general, Iris growers identify I. setosa in its many forms as being setosa BECAUSE IT HAS NO STANDARDS, or standards reduced to "bristle-like growths" in which case the setosa shown above (and below) is not setosa at all. Generally too, I. hookeri is accepted as a small-growing form of setosa and so also has no proper standards. I. setosa has a huge natural range almost circumpolar in the northern hemisphere and I myself grow at least 5 separate forms which range from 20 cms to 90 cms in height. I also have a form which I was given as seed, as I. setosa var platyrhyncha which, according to Mathew has larger, more expanded standards than the usual. I have seen the parent plant, quite different from the standardless forms, yet the seedlings have flowered exactly the same as what I know as var. hookeri with no standards. Mathew lists hookeri as a synonym of var. canadensis. So far as confusion is concerned, I'm really not that bothered any more. My original beef (in the thread that Maggi has separated off) was not about confusion between setosa and hookeri but between hookeri and hookeriana which is from the Section Pseudoregelia but regularly turns up in seed lists only to be found to be hookeri or a form of setosa, not hookeriana at all.

[Lesley Cox]

Regarding the standards apparent on some setosa, I suspect there is hybridising going on that is yet not fully recognised. Certainly it crosses with both versicolor and ensata, the large Japanese irises, in the wild. There are some advantages to getting quite old. In many instances what seemed wildly important a while back, now seems not to matter at all!

[Karaba]

For example, reply#5 above shows I. hookeri mostly with branched stems, inconsistent with the Flora of North America description

I don't see any branch on Iris hookeri in your picture (reply #5). They can have 2-3 flowers by stem grouped in a bract which can look as a branch when theyr are in fruit.
On pictures by Rick (reply #2), Iris seems to be branched

[Gabriela]

However is this Iris setosa, growing near St. Johns?   I. versicolor?

I think so too Ashley, I. versicolor is given as having leaves 'proeminently veined', and they look like that.
To complicate things even more they say it was shown that "Iris versicolor arose as an amphidiploid between I. virginica (n = 35) and I. hookeri (I. setosa var. canadensis) (n = 19). Back-cross hybrids have been produced both ways."

Re I. hookeri - FA says stems 'usually simple' so not always, and there must be great variability in forms, reason why maybe they didn't agree on the name. Who knows, maybe I. setosa var. canadensis would have been better but I'm in no position to argue about this.
I never even saw it in the wild, so...

I suspect that especially in cultivation there are also various hybrids - I should note that for my posted images.

[Gabriela]

Funny, we were cross posting here 

Regarding the standards apparent on some setosa, I suspect there is hybridising going on that is yet not fully recognised. Certainly it crosses with both versicolor and ensata, the large Japanese irises, in the wild. There are some advantages to getting quite old. In many instances what seemed wildly important a while back, now seems not to matter at all!

You are certainly right Lesley!
That's why is so important to have seeds collected in the wild, of well ID plants of course.

Yvain - agree with you.

[Karaba]

Certainly it crosses with both versicolor and ensata, the large Japanese irises, in the wild.

According to http://www.japan-iris.org/English/wild_iris.html, it also hybridize with I. sanguinea and laevigata in Japan (see also https://www.jstage.jst.go.jp/article/cytologia/78/4/78_449/_pdf)