Hydrangea blooms resemble other hydrangea blooms too much so I quit trying to identify specific varieties a long time ago. I have an unnamed mophead that was here when I bought the house. That started the list of unknown plants. Then Lowes sold me a Nikko Blue Mophead that turned out to be a lacecap hydrangea so, add a second unnamed hydrangea to the list of unknowns. Ha!
The good news is that one does not need to be concerned as the care for any lacecap hydrangea is usually the same as for any other lacecap or any other mophead...
Hydrangea serratas -many of them but not all- also have lacecap flowers but serratas are like "mini" hydrangeas, more compact and bloom later in Spring. Otherwise, care for serratas is usually the same as for lacecaps and mopheads too.
The only difference I can think of at this moment is the variegated lacecaps, which require a little less direct sun & warmer usda zones to perform at their best and the Hydranea macrophylla Teller Hybrids, which include some hydrangeas that are only hardy to Zone 7..
If you want to pursue identifying, check the ones for sale below.
Here is a link of Hydrangeas Plus list of macrophylla mopheads and lacecaps:
http://www.hydrangeasplus.com/...
Here is a link of Hydrangeas Plus list of serratas (most have lacecap blooms):
http://www.hydrangeasplus.com/...
Here is a link of Hydrangeas Plus list of Arborescens Hydrangeas (some have lacecap blooms). Their care can be different from lacecaps.
http://www.hydrangeasplus.com/...
There are some more lacecpas called Hydrangea asperas but they are not sold wildly, are very large and have fuzzy leaves. And there is the Climbing Hydrangea with lacecap blooms. I assume yours is not one of those but I wanted to mention in order to be complete.