Umbellet (umbellula), a secondary or partial umbel, [76].
Umbilicate, depressed in the centre, like the ends of an apple; with a navel.
Umbonate, bossed; furnished with a low, rounded projection like a boss (umbo).
Umbraculiform, umbrella-shaped.
Unarmed, destitute of spines, prickles, and the like.
Uncial, an inch (uncia) in length.
Uncinate, or Uncate, hook-shaped; hooked over at the end.
Under-shrub, partially shrubby, or a very low shrub.
Undulate or Undate, wavy, or wavy-margined, [55].
Unequally pinnate, pinnate with an odd number of leaflets, [65].