Kokio ula are either shrubs or small trees that can grow to 21 feet tall, though they are usually a bit smaller than that. Young plants usually have one main stem growing upright with many smaller branches coming out horizontally, giving them an almost cone shape. If the main stem of young plants is pruned early on, the plants can have several main branches and have a squarer growth habit.
The leaves of Hibiscus kokio are variable in size and shape but are generally narrowly triangular and glossy green. The leaves range in size from 1 inch long and ½ inch wide to more than 8 inches long and 4 inches wide. The edges of the leaves have either rounded or pointed “teeth,” but sometimes the edges are smooth. The edges of the leaves of Hibiscus clayii usually are smooth but sometimes have pointed “teeth” at their tips.