Trapeziform, shaped like a trapezium.
Trigonal, having three angles.
Truncated, stunted, cut short or abruptly off at the end.
Tubercle, a little knot or pimple.
Tuberculated, knotted, pimpled.
Tuberosities, prominent knots or excrescences.
Tubular, in the shape of a hollow tube.
Tubulate, tubulous or hollow.
Tunicated, coated.
Turbinated, shaped like a top or pear.