I couldn't find a flower or fruiting stalk among the several yucca plants I saw near the HQ of Fort Parker State Park, near Groesbeck, TX. Nonetheless, the leaf clusters best match Y. arkansana.

I thought this was going to be a fairly simple yucca ID based on the location in the oak woodlands of east-central Texas (Limestone Co.) but I find out that both Y. arkansana and Y. louisianensis range broadly through this area. Yet, curiously, there seem to be no yucca records mapped for Limestone County (at all) in the PLANTS database or on BONAP.
http://plants.usda.gov/core/profile?symbol=YUCCA
http://bonap.net/NAPA/TaxonMaps/Genus/County/Yucca