The holywood lignum vitae (Guaiacum sanctum) is a stunning tree which produces beautiful blue flowers, either solitarily or in clusters. These flowers have five petals and usually measure just over a centimeter across. The leaves of the holywood lignum vitae comprise of three to five pairs of dark green leaflets, which measure about three centimeters in length and have a small point at the tip. During the hottest part of the day, the leaflet pairs may sometimes fold together. The fruits of this species have four or five lobes and are bright orange-yellow when mature. They open to expose red, fleshy arils (seed coverings) which contain the hard, black, rounded seeds. The seeds of the holywood lignum vitae measure about one centimeter in length. The holywood lignum vitae generally grows as a relatively low tree with a gnarled truck and a spreading, rounded crown of drooping branches. Its wood is notable for its unique greenish-brown color. The wood is strong and dense, and sinks when placed in water. It is a rare and collectible plant.
The seed coats of the seeds contain germination inhibitors and so the seeds have to be treated before they will germinate. Soak the seeds in water for 24 hours. Then nick the seed coat to allow water into the seed. Some of the seeds will germinate when they are nicked but the best way to get the seeds to germinate is to remove the black seed coat from the seeds. Seeds that have the seed coats removed have a good germination rate. The seeds should be planted 1 cm deep in a sandy, moist but well-drained medium. They can be planted in a mix of sand and compost, vermiculite or potting soil. When the seeds are about 1 foot tall, they can be transplanted. Plant them in an area in full sun or part shade with well-drained soil. Lignum vitae is a very hardy tree and is tolerant of drought, poor soils and salt water.