Well, actually, I've been growing 'Celeste' for a long time, and I thought yours looked familiar. However, there are lots of details to note that can help identify Iris. The more cultivars that are introduced however, the more there are to sort through. There are a lot of old ones, but at least no new old ones :) Some things to look at are the colors of parts such as the leaf bases, the styles, the bracts, etc. If it's a pallida, it will always have the bracts papery, not green, when the flowers are open. The hybrids with other species involved rarely have bracts like this. The way the petals are held, and their shape are often distinctive. The color, shape and density of the beard are useful to note. The pattern of stripes at the base of the falls (and often the standards too) are very distinctive, and while they are not identical on any two flowers, even on the same plant, they are consistent in basic arrangement and appearance within any given cultivar, and they can be very useful for identification. Of course none of this is any use if you don't have a properly labeled flower or photo of a flower to compare with, or if the color of the foliage base is not shown or noted. Luckily, there are photos on the internet now of most of the old cultivars. The Historic Iris Preservation Society has lots of photos. Superstition Iris has lots of good ones. Argyle Acres' website is good too, but varies from year to year depending on what is offered for sale at the time. And so on.
If you do some digging, you should be able to find lots of photos of 'Celeste'.
Iris pallida is species that grows in the wild, and it is variable. It can be anywhere from 10 inches to 3 ft tall, but mostly about 2 ft is a common height for many individuals of the species. The literature claims the bracts are not only papery, but "silvery" or "white". This is often true, but they can be pale brownish too. Flowers are smallish and tend to be rather vertical looking (falls pointing down); they can be white, light rose-pink, or light purplish blue. There is one very dark bluish cultivar called 'Floridor', and there are numerous cultivars that are plicatas of the type that are mostly white with edges stiched with color. Most Iris pallida have flowers that smell of grape soda (wonderful when planted en-mass). This species is in the ancestry of most tall bearded Iris cultivars, but many of it's distinctive characteristics are hard to see in these more modern hybrids.
The most common bluish cultivars are 'Dalmatica' and 'Odoratissima'. Both are very commonly grown. They are similar, but 'Dalmatica' tends to be a bit larger, and 'Odoratissima a bit more prolific grower and with stronger fragrance to the flowers. If I remember correctly, 'Dalmatica' doesn't make pollen and 'Odoratissima' does (I may have that switched?).
Most of the old hybrids of I. pallida are the result of I. pallida x I. variegata, but other species might be involved too. They tend to have a musky smell (Elder Iris is a common name for some of them), and they tend to have falls that spread out just a bit more. The bracts are usually mostly or at least partly green and foliacious. There are many of these, a large percentage originally "bred" in France. Very few were released after around 1930, because they weren't as striking as the newer tetraploid hybrids that were begining to dominate the market. A few people are playing with these (and other) wild species again. Tom Silvers has posted lots of photos of interesting new hybrids that look very much like these older ones here.
Hope that helps.
> To: email@example.com
> From: firstname.lastname@example.org
> Date: Fri, 25 Apr 2008 21:21:47 -0600
> Subject: Re: [iris-photos] Lavender Iris ? follow-up
> Can you point out how you knew? I have trouble telling the difference between the various Pallidas and the Pallida crosses....
> Ann Conway
> ----- Original Message -----
> From: David Ferguson
> To: email@example.com
> Sent: Friday, April 25, 2008 9:09 PM
> Subject: RE: [iris-photos] Lavender Iris ? follow-up
> I did some comparing, and I think your lower #3 photo is indeed 'Celeste'. This is a very commonly grown old cultivar.
> Here is a link to a nice photo of it on Flickr.
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