This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
Aromatic evergreen shrubs or small trees. Sepals 3 or 6, membranaceous. Petals many. Filaments fleshy. Carpels several, in a single whorl, 1-seeded, coriaceous, dehiscing along the inner. or superior margin. One North American species, and four or five from China and Japan.
1. I. religiosum, syn. I. anisatum. - A small shrub with terminal clusters of small yellowish white flowers. This is tender and rarely seen.