Guajacum sanctum
Common Names: holywood lignum-vitae, lignum-vitae, tree-of-life
Family: Zygophyllaceae (caltrop Family)
tree Shrub Drought Tolerant Has evergreen foliage, Flowers
Description
Holywood lignum-vitae is a handsome large shrub or small tree with
shiny evergreen leaves, fissured light gray bark, and the bluest
flowers you will ever see on a tree. The tree can get up to 30 ft
(9.1 m) tall, but usually is around 15 ft (4.6 m) tall. The 4 in
(10.2 cm) leaves are pinnately compound, and borne in opposing pairs
originating from swollen nodes along the slender, crooked, somewhat
drooping branches. Each leaf has 2-5 pairs of 1.5 in (3.8 cm) oblong
leaflets, and each leaflet has a tiny apical tooth. An unusual
characteristic of lignum-vitae is that the pairs of leaves are held
in the same plane; most plants with opposite leaves hold them at
right angles to each other. Flowers are produced at the tips of
shoots singly or in few-flowered clusters during March and April.
The flowers are almost 1 in (2.5 cm) across and the petals are true
blue (a real rarity). The fruit is a brown 5-lobed capsule that
splits open when ripe in September or October to expose black seeds
that are enclosed in a fleshy red pulp.
Location
Holywood lignum-vitae occurs naturally (but uncommonly) in dry
coastal areas throughout the Caribbean basin including the Bahamas,
West Indies, Yucatan, Central America, and in the middle and upper
Florida Keys. Holywood lignum-vitae was once common on the lower
Florida Keys and Key West, but it was completely exterminated there
by over harvesting for its valuable wood. Today the species is very
rare in Florida and only a few specimens remain. Holywood
lignum-vitae is listed as an Endangered species by the State of
Florida. Best place in the US to see holywood lignum-vitae is at
Lignumvitae Key State Botanical Site on Islamorada.
Culture
Light: Full sun to light shade.
Moisture: Lignum-vitae is drought tolerant and requires a soil with
excellent drainage.
Hardiness: USDA Zones 10 - 11.
Propagation: By seed or by new-growth tip cuttings in spring. Seeds
are difficult to germinate because (like many tropical trees)
lignum-vitae seeds have a natural tendency to remain dormant for a
long time. Germination can be hastened by soaking the seeds in a
0.1% solution of gibberellic acid.
lignum-vitae
Lignum-vitae is a handsome, drought resistant small tree for
tropical landscapes.
Usage
Use lignum-vitae in tropical seaside settings. It is resistant to
salt spray and tolerant of drought, so would be a good choice for
dry, sandy soils near the coast. Lignum-vitae makes a handsome
specimen or, used in groups, an effective hedge. It grows very
slowly, so don't use lignum-vitae if you want a quick screen!
Lignum-vitae also is grown in containers, where it will stay small
for many years.
Features
There are six species of lignum-vitae, all native to dry tropical
forests in the New World, and all rather similar in most
characteristics. Lignum-vitae is the national tree of the Bahamas
and the flower is the national flower of Jamaica. Texas lignum-vitae
(G. angustifolium) occurs in the Rio Grande valley.
Lignum-vitae has the hardest wood of any commercially harvested
tree. The wood is yellowish or greenish brown and has a resin
content of about 30% by weight. Lignum-vitae wood is exceedingly
heavy (it will not float), close grained and split resistant, and is
valued for propeller shaft bushings, machine parts, and other
applications in which its natural resins make it self lubricating.
Lignum-vitae also is the source of gum guaiacum, a resin once used
in the treatment of syphilis and arthritis. The common name refers
to its supposed holy and life giving properties. There are about 250
species in the family, many of which are typical of deserts, such as
the creosote bush (Larrea divaricata). |
