Definition of "nontiered"

The Chilean Amphijubula Schust. (Schuster, 1970a) which has the facies of a small Frullania and agrees with Frullania in leaf insertion and branching, has a nontiered seta with 16 epidermal cell rows surrounding 4 inner rows.

1992, Rudolf M[athias] Schuster, The Hepaticae and Anthocerotae of North America: East of the Hundredth Meridian, volume V, New York, N.Y.: Columbia University Press, page 6