I agree with your identification. Common names are Oxblood or Schoolhouse Lily. They are more common in central Texas, but will grow in the Houston area. They were brought to Texas by German immigrants. I brought a clump with me when I moved from Austin in 2015. They didn't bloom last year and I'm starting to see some foliage now, which makes me think I may not get blooms this year either. I know they don't like to be moved, so I'm just going to be patient.
