transect (transectus, cut through), a cross section of vegetation.

trechometer (τρέχω, to run off), an instrument for measuring run-off.

tribi´um (τρίβω, wear or rub away), a succession in an eroded soil.

umbrinus, umber.

variable, able to produce variants; variant, a form arising from origin by variation; variation, the origin of new forms by the action of selection upon minute differences.

vegetation form, a characteristic plant form, e. g., tree, rosette, etc.

vernal, pertaining to spring.

vicine (vicinus, neighboring), invading from adjacent formations.

viridis, green.

vixgregarious, arranged in small or indistinct groups.