straight-joint

from The Century Dictionary.

• Noting a floor the boards of which are so laid that the joints form a continuous line throughout the length.

from the GNU version of the Collaborative International Dictionary of English.

• adjective Applied to a floor the boards of which are so laid that the joints form a continued line transverse to the length of the boards themselves.
• adjective In the United States, applied to planking or flooring put together without the tongue and groove, the pieces being laid edge to edge.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective architecture Whose boards are laid so that the joints form a continued line transverse to the length of the boards themselves.
• adjective architecture, US Put together without the tongue and groove, the pieces being laid edge to edge.