PowerShell To List Site Template
SharePoint 2010 Management Shell makes it easier to get a list of Site Templates installed in the farm and also creating sites using the names is straight forward.
To get a list of all globally installed site templates use the following PowerShell cmdlet
get-spwebtemplate
To get the basic information about all the STS template, use the following PowerShell cmdlet
get-spwebtemplate “STS*”
To get the basic information about all the SPS template, use the following PowerShell cmdlet
get-spwebtemplate “SPS*”
Thanks this worked for me