It is hard to say exactly without knowing exactly which kind of iris they are. If they actually have bulbs and not rhizomes then I don't really have much experience with those kinds of iris. If they are growing from rhizomes they could be Siberian iris, or even spuria iris. Anyway, without knowing for sure which kind you are talking about, I would say most iris need full sun, and dividing when the roots get crowded. But they do have different water needs and different best times for dividing. Has your SIL ever seen them bloom or let the leaves grow to their full height so we could get a better idea how to respond?

She said she saw them bloom before and they were delicate looking and purple ?? The leaves are still on them now - she hadn't mowed them down yet from last year . I am going to dig the rest of them up Sunday and I will take a picture before I do . I am planning on cutting the leaves back first - then dig them up . They are a tangled mess and all the clumps are growing together . I will post a photo Sunday . Thanks again

Here is the photo of the plants before I dug them up . They are the long spiky looking leaves . Some of the bulbs were huge - larger than a golf ball . The bulbs were also white in color . Can anyone tell me if these are Iris ? My niece says they have purple flowers and get as high as 36" tall .

Those don't look like irises to me- but maybe they are Dutch Irises, which are bulbs. This is a fun mystery!
Renee

I thought Dutch iris were more like two feet tall or so. Those leaves look more like daylily leaves, but then daylilies don't have bulbs. Could they be the pink Lycorus squamigera? They get leaves in the spring, die back until about the beginning of August, and then the bloom stalks appear without leaves. I think Lycorus bulbs have a brown papery coat, though.

No I don't think they are the pink Lycro because my niece said the flowers are definately purple and yes the leaves look just like daylillies so I was shocked when I saw these huge bulbs and I just noticed that some of the bulbs have a brown papery coat on them . Here is a picture of one of the bulbs . Is there a purple version of the plant you are talking about and is there a common name ?

That looks like a lycorus bulb but is she sure it gets purple?

Yep looks like mine.
They will bloom later this summer after the leaves have died back.
Very hardy

So does each bulb produce 1 flower ? I have several hundred bulbs and am wondering how close together to plant them - yours seem close .

They look like naked ladies to me.

Yes each bulb has one flower.
My leaves are starting to die back now ,late summer is when the flowers pop up.
I always forget about them since the leaves die back and surprise up they come.

So if they are naked ladies then what happens to the big clump of long spiky leaves ? Do you clear them away after they die back ? When I dug these up and divided them I filled 4 wheel barrel full of leaves and hauled them off . I really wish I could identify these because if I cant plant them all - I'd love to be able to share them with friends and neighbors .

The long leaves brown up like spring bulbs' leaves do, and I just clear them away when they are dead and compost. Some folks plant them with other plants such that their absence during the early summer isn't so noticeable. The link below is a photo of such a planting. Most of them around here struggle along in the lawn like at your SIL, and if they aren't mowed while the leaves are present or when the blooms start, then their flowers are very pretty. I don't recall any that are purple, though. Most Lycorus are not hardy, and are red or yellow and are called spider lilies. I think they have naturalized in the southeast. I had some at my old house that I rescued out of the lawn when I figured out what they were. About planting, they will increase, so you don't want to plant them too close together. They don't like to be moved, and so they might not bloom the first year after you plant them. Well, I guess this is all only if the bulbs really are Lycorus.

Here is a link that might be useful: A pretty planting