TREES AND WOODS OF THE LIGNUM-VITAE FAMILY
The true lignum-vitae belongs to the family Zygophyllaceae. The plants
included in this family are mostly herbs, undershrubs, and shrubs;
many of them are xerophytic. The only trees of the family belong to
three[1] closely related genera, namely _Guaiacum_, _Porlieria_,[2] and
_Bulnesia_. These are confined to tropical and sub-tropical regions of
the Western Hemisphere.
[1] The genus _Balanites_ is included in the Zygophyllaceae by some
botanists, but the structure of the wood has no resemblance to that of
the three genera herein described.
[2] Some botanists do not accord generic rank to _Porlieria_, but
include it as a section of the extended genus _Guaiacum_ (see 40, p.
59).
These three genera are composed of mostly evergreen trees and shrubs
with opposite, compound, abruptly pinnate leaves, and with showy
flowers solitary or in umbel-like clusters. The fruits are 2-5 lobed or
parted, and each portion contains usually a single seed.
_Guaiacum_ and _Porlieria_ are alike in having blue or purple flowers,
and leathery fruits containing seeds covered with a thin fleshy and
often highly colored exocarp. _Bulnesia_, on the other hand, has yellow
flowers, and the fruit, instead of being fleshy, is a 5-parted dry
capsule with each part flattened into a conspicuous wing. The seeds are
not provided with a fleshy covering.
In _Guaiacum_ the stipules are deciduous, and the stamens are almost
invariably without appendages. In the other two genera the stamens have
prominent appendages and the stipules of the leaves are persistent,
being thorny in _Porlieria_. The latter genus is further characterized
by having small linear leaflets which exhibit nyctitrophic or “sleep”
movements, and flowers that are tetramerous instead of pentamerous as
they are in the other two.
These trees are found commonly in very dry regions and are accordingly
of very slow growth, short-boled and bushy. The trunks, however,
are often very stout with little taper. Some of the species of each
genus are typically shrubs and others tend to become so in the most
unfavorable sites. In the better situations, however, the trees grow
more rapidly and are taller, straighter, and smoother, though such
timber is not necessarily better and may, indeed, be of poorer quality
on that account.
The woods of _Guaiacum_, _Porlieria_, and _Bulnesia_ have many
properties in common. They are cross-grained, extremely hard and
horn-like, and are considerably heavier than water even when thoroughly
dry;[3] the heart portion is infiltrated with a fragrantly scented
gum-resin which gives the wood an oily appearance and feel.
[3] The maximum density determined by the writer was 1.32 (about
82-1/2 lbs. per cubic foot) for Nicaraguan lignum-vitae. Krais (“Die
Hölzer”) gives the range for dry wood of _Guaiacum_ as 1.17 to 1.39, or
from 73 to nearly 87 pounds per cubic foot. Other reliable figures of
density are 1.248 (Laslett) and 1.33 (Beauverie). Stone (46) gives 89
pounds per cubic foot for _Guaiacum sanctum_ and cites Sargent (40) as
authority. This is an error, as the values given by Sargent are 0.9563
to 1.2736, average 1.1432. Boulger (5) uses the same figure as Stone.
Growth rings are often distinct, largely on account of color
variations, though affected more or less by the relative abundance
of pores and by the distribution of wood parenchyma. The woods are
diffuse-porous and the pores, which vary in size from minute and
indistinct to readily visible in some cases, are open in the sapwood
but commonly filled with resin in the heart. They are often associated
with or surrounded by parenchyma which may extend into fine tangential
or irregularly spaced concentric lines. The rays are uniform and
numerous but are too fine to be seen without a lens.
On the longitudinal surface, typically the tangential, very fine and
regularly-disposed cross-lines or “ripple marks” are visible with the
lens but not without it. These lines are at right angles to the axis
of the tree and are not affected in direction or regularity by the
criss-crossing of the fiber-layers. The number of these markings per
inch of length averages about 250, which is so much greater than in
any other wood that this feature alone is sufficient to establish the
identity of the group (36, p. 259).[4] These ripple marks are also
characteristic of the inner bark (secondary phloem). (For structure of
the bark of _Guaiacum officinale_ see Joseph Moeller’s “Anatomie der
Baumrinden,” Berlin, 1882, pp. 332-3.)
[4] In a specimen (Yale No. 974) of the shrub _Larrea divaricata_
Cav. (Zygophyllaceae) from Argentina the number of ripple marks is
about 270 per inch. In this wood the ground mass is composed of small
thick-walled fiber-tracheids with very abundant and prominent bordered
pits. The rays are 1 to 12, mostly 6, cells high, uni-seriate or more
commonly bi-seriate in the median portion; rather indistinctly storied.
The wood parenchyma contains crystals some of which are large and
conspicuous.
Porlieria
The representatives of this genus are shrubs or small trees growing
in dry sub-tropical regions, and are not of commercial importance.
Four species have been described, one belonging to a group of
plants connecting the Mexican and Texas flora, two inhabiting the
corresponding zone in Argentina and Chile, and a fourth,[5] little
known, in Bolivia.
[5] This fourth species is described by Baillon (Adansonia, 10:315-16,
1872) under the name of “_Guaiacum (Porlieria) microphyllum_.” It was
found in Bolivia. The leaves are only 1/5 inch long and 1/6 inch broad.
_Porlieria angustifolia_ Gray (= _Guaiacum angustifolium_ Engl.) is
found in western Texas and adjacent regions of Mexico where it is
common on the dry gravelly mesas of the valley of the lower Rio Grande.
It is a small tree with very knotty branches, attains a height of 25
to 30 feet and a diameter of 6 to 8 inches, becoming reduced to a low
shrub toward its eastern, northern, and western limits. “The hard and
heavy yellowish-brown wood is called ‘guayacan’ about Saltillo, and
used as a sudorific and in venereal diseases.” (12, p. 113.)
“The wood is exceedingly heavy, very hard, close-grained, compact, the
open ducts smaller and less regularly distributed than in _Guaiacum_;
medullary rays very thin, numerous; color, rich dark brown turning
green with exposure, the sapwood bright yellow; sp. gr. 1.1101; ash
0.51; probably possessing medicinal properties similar to those of
lignum-vitae.” (39, p. 29.)
_Porlieria Lorentzii_ Engl. is a shrub or small tree on the Argentine
steppes where it occasionally reaches a height of 25 feet and a
diameter of 10 inches. It is covered with a thin dark gray scaly bark.
The yellowish wood is very compact and fine-textured and makes a fairly
satisfactory substitute for boxwood in turnery and carving. Its most
common use is in the manufacture of domestic utensils, particularly
spoons, and to the latter owes its vernacular name of “cucharero”
(maker of spoons). The Indians use the wood, called by them “chukupi,”
for making smoking-pipes (44, p. 378; 49, p. 105.)
The above is probably the species referred to by Castro (8, p. 77)
as “guayacan blanco,” “chuchupi,” “chucupi,” or “chucarea,” though
he gives the scientific name as _P. hygrometrica_. The following
information is on his authority: The tree is found in Córdoba, Salta,
Jujuy, Tucuman, Mendoza, San Luis, San Juan, and La Rioja, and is very
abundant in the Andean provinces. In its better development it reaches
a height of 13 to 20 feet and a diameter of 4 to 6 inches. The wood
is hard and very strong and resilient. Specific gravity 1.11. It is
susceptible of a high polish, has a high luster, and on account of its
flexibility is in demand for canes and whipstocks. It is also used for
turnery and carves with ease. In general carpentry it finds a place in
the making of sash, doors, and blinds.
_Porlieria hygrometrica_ R. & P. (= _Guaiacum hygrometricum_ Bail.),
is an ungainly shrub with sprawling branches and dropping leaves. When
it “sleeps” it gives the appearance of being diseased or even in a
dying condition. It was discovered by Ruiz and Pavon, first in Peru
near Huanuco, where it was called “turucasa,” meaning “thorns fragile
and not sharp” (referring to the stipular spines); afterwards in Chile
where the Spaniards, who have imputed to it the sudorific property of
guaiac, call it “guayaco,” also “palo santo.” Misled, no doubt, by
the common name, Molina, who did not see the plant, has erroneously
referred to it as _Guaiacum officinale_ L. (13, pp. 465-6.)
Bulnesia
This genus, so far as known, is confined to South America. There are
eight species, but only two, the “palo santo” of Argentina and the
“vera” of Colombia and Venezuela, supply timber of commercial value.
The others are low-branching shrubs on the dry foothills of the Andes
Mountains in Argentina.
_“Retama” or “Retamo”_[6]
[6] In Patagonia the name “retamo” is given to _Lippia juncea_ Sch.
(38, p. 194).
_Bulnesia Retamo_ Gris. is one of the latter group which sometimes
develops into a short stout broom-like tree with a height up to 25
feet and a diameter of from 10 to 20 inches. According to Castro (8,
pp. 131-2) the tree occurs in Misiones, San Luis, La Rioja, San Juan,
Córdoba, and Catamarca. The tree is said to be of fine appearance and
the branches, which are without leaves during the greater part of the
year, are slender and pendulous. The gray-yellowish-green bark is from
7 to 8 mm. thick and has prominent corky lenticels and shallow furrows.
According to the same authority, the sapwood is yellowish-white, the
heartwood dark-yellowish with veins of deeper color. The specific
gravity is given as 0.917. The moduli of elasticity in bending, in
kilograms per square millimeter, are: maximum 1,053; mean, 897;
minimum, 780. The coefficients of resistance to rupture in bending,
in kilograms per square millimeter, are: maximum, 12.25; mean, 7.50;
minimum, 4.50.
The wood is “hard as iron” and is used to a limited extent for
cross-ties, carpentry, posts, canes, tool handles, and also in
the construction of furniture of “great durability and beautiful
appearance.” The twigs and leaves have a place in medicine and the
boughs are used by the mountaineers for thatching their huts. The
charcoal from retamo wood is of a very high quality. Spegazzini (44,
p. 397) states that the wood makes excellent fuel and occasionally
supplies material for turnery.
_“Palo Santo” or “Palo Balsamo”_
This wood is supplied by _Bulnesia Sarmienti_ Lorentz which is
“indigenous to the Argentine province of Gran Chaco about halfway
up the Rio Berjemo” (17, p. 453); Castro (8, p. 56) says it grows
in Chaco, Salta, Tucamán, Jujuy, and Corrientes; it also occurs in
Paraguay. It attains a height of 50 or 60 feet and a diameter of 40
inches (44, p. 376), has a straight bole with a very thin smooth gray
bark, and in the interior of the Chaco generally rises above all of the
other trees in the forest (49, p. 105). It is a tree of the dry regions
and is for the most part in groups or patches yielding at most only a
few hundred board feet per acre. Although the wood is well known to
certain local minor industries making small cabinets and turnery, it is
not obtainable in any considerable amount.
The sapwood is narrow and light-colored; the heartwood is usually
deep-brown, often more or less greenish, and sometimes with alternate
lighter and darker bands. The pores are small, thick-walled, numerous,
and arranged in radial lines or groups, sometimes spreading or
branching outward as in the late wood of white oak.
The specific gravity, as determined by the writer on two specimens,
oven-dry, is as follows: All-heart specimen, 1.21; specimen with
one-fifth sapwood, 1.18. According to Castro (8, p. 56) the sp. gr. is
from 1.216 to 1.303. The moduli of elasticity in bending, in kilograms
per square millimeter, are: maximum, 988; mean, 872; minimum, 827.
The coefficient of resistance to rupture in bending, in kilograms per
square millimeter, are: maximum, 14.07; mean, 10.81; minimum, 8.91.
The heartwood is thoroughly impregnated with resin of the nature of
guaiac and contains in addition a small amount of essential oil which
is fragrantly scented, somewhat suggesting sandalwood. This odor is
quite pronounced upon heating and the wood is in local demand for
incense in churches; hence the name “palo santo”[7] (holy wood). It is
used by the Indians in northern Argentina for firewood, torches, and
the making of utensils for various purposes.
[7] In Patagonia the name “palo santo” is given to _Flotowia
diacanthoides_ Less. (38, p. 192).
The name “palo balsamo” is a commercial term which has been in use
since 1892, and refers to the oil content of the wood. By distillation
the heartwood yields 5 or 6 per cent of this oil which is known to the
trade as “oil of guaiac wood,” “oleum ligni guaiaci,” “Guajakholzöl,”
or “essence de bois gaïac.”[8]
[8] The name “champaca oil” was later given to this same oil although
it has not the slightest resemblance to the genuine champaca oil from
_Michelia champaca_ L. (Bericht von Schimmel & Co., Apr. 1893, p. 33).
(17, p. 453.)
For many years the manufacture of this oil was confined to Germany and
France, but during the war 2,000 pounds were distilled in New York.
Since the sale is limited, this represents at least a five years’
supply. The wood is obtained in the form of logs, reduced to sawdust
and fine chips, and distilled. Efforts to obtain the oil from the wood
of _Guaiacum_ were without success. Apparently no effort has been made
to distill it from _Bulnesia arborea_.
Oil of guaiac wood is a viscous, heavy oil, yellowish in color, which
at ordinary temperature gradually solidifies to a crystalline mass. The
crystals are needle-shaped, sharply outlined, and characterized by a
channel-like middle line. The solidified oil is white and of about the
consistency of cold lard. The melting point is between 40° and 50°C.
The odor of the specimens examined by the writer is mild, slightly
pungent, and vaguely suggesting rose.
The following description of the properties and composition of the
oil of guaiac wood is from Gildemeister and Hoffman (17, pp. 453-4).
“The odor of the oil is very pleasant, being violet and tea-like.
The specific gravity lies between 0.965 and 0.975 at 30°; the angle
of rotation is -6° to -7° at 30°. The oil is soluble in 70 per cent
alcohol. The saponification number found of an oil was 3.9, the ester
number 2.4, and the acid number 1.4.
“The crystalline constituent of the oil is guaiac alcohol or guaiol
(Wallach), a sesquiterpene hydrate C₁₅H₂₆O. Guaiol is an odorless
body, crystallizing in large transparent prisms, and melting at 91°.
It boils under ordinary pressure at 288°, at 10 mm. pressure at 148°.
Its solution in chloroform is laevogyrate. With dehydrating agents
a hydrocarbon C₁₅H₂₄ is formed, accompanied by an intensely blue
substance. On boiling guaiol with acetic acid anhydride a liquid acetyl
compound is produced which boils at 155° under a pressure of 10 mm. The
odoriferous constituent of the oil has not yet been investigated.”
The New York manufacturers of oil of guaiac wood sell the oil in small
quantities to perfumers, mostly in France, the price (1919) being about
$2 an ounce. They inform the writer that they are not familiar with the
use the perfumers make of it. According to Gildemeister and Hoffman
(17, pp. 436, 454), it is used in the perfume industry for the purpose
of producing a tea-rose odor and also as an adulterant of oil of rose.
_“Vera” or “Maracaibo Lignum-vitae”_
These names are applied to _Bulnesia arborea_ Engl. (= _Zygophyllum
arboreum_ Jacq., = _Guaiacum arboreum_ DC.) which occurs in the
coastal region of Colombia and Venezuela. (See plate.) According to
Sargent (40, p. 60) this species is “widely distributed through the
northern countries of South America from Cartagena to Venezuela.” The
fact that it was formerly, and occasionally is now, referred to as a
species of _Guaiacum_ accounts for some of the conflicting statements
regarding the range of that genus. Flückiger says (14, p. 102): “This
tree, occurring in New Granada (Colombia), has already been noticed
(1571-1577) by Francisco Hernandez (Nova plantarum, animal. et mineral.
Mexicanor. hist. Romae 1651, fol. 63) under the name of guayacan. He
mentions its large umbels with yellow flowers, those of _Guaiacum
officinale_, the ‘hoaxacan’ or lignum sanctum, being blue.”
Triana and Planchon (47, p. 362) describe this tree under the name
of _Guaiacum arboreum_ DC. and call attention to the differences in
flowers and fruit between it and _G. officinale_. They report its
occurrence in Colombia in the valley of the Magdalena up to an altitude
of 2,600 feet above sea level, in Cartagena, the savannas of the valley
of Uphar, Santa Marta; and in Estado Carabobo of Venezuela. The common
names of “guayacan” and “guayacan polvillo” are given for this species
and the wood is described as being of a dark yellow color tending to
greenish and with an almost pulverulent fracture. There is indication
of confusion of species here since the name “guayacan polvillo” is
commonly applied to a certain species of _Tecoma_ or _Tabebuia_
(Bignoniaceae) and the pulverulent nature of the fracture would seem to
refer to the lapachol compound which abounds in the wood of this and
closely related species.
Stone (46, p. 18) describes the wood of _Bulnesia arborea_ under the
name of _Guaiacum arboreum_ DC., and gives its source as Brazil,
citing Miers as authority. The only other reference to the occurrence
of this tree in Brazil that the writer has found is by Beauverie (3,
p. 248) who apparently follows Stone and it seems probable that this
information was incorrect, especially so in view of a statement by
Huber (24, pp. 179-180) to similar effect.
The wood of _Bulnesia arborea_ is known to the trade as “vera,”
“vera-wood,” and “Maracaibo lignum-vitae.” The most common local name
for it is vera.[9] The variations in the color of the wood, attributed
to the effect of site, give rise to the names “vera aceituno” (olive),
“vera amarilla” (yellow), “vera azul” (blue), and “vera blanca”
(white). “Guayacan” and “palosano” are synonyms for vera (1, p. 178).
Another native name, a variant of vera, is “bera” or “berra.” Humboldt
(25, pp. 7-8) says: “On leaving Cumana we enjoyed during the short
duration of the twilight from the top of the hill of San Francisco,
an extensive view over the sea, the plain covered with _bera_ and its
golden flowers; and the mountains of the Brigantine.” A foot-note
referring to the tree reads: “Palo sano, _Zygophyllum arboreum_ Jacq.
The flowers have the smell of vanilla.”
[9] The wood, along with true lignum-vitae, has recently been
introduced in the brush-back trade under the fantastic name of “Congo
cypress”!
Vera usually grows in places more favorable for its development than
is the case of the other zygophyllaceous trees. Consequently it is
often comparatively slender, straight-boled, and of rather good timber
form. Sargent (40, p. 60) calls it a small tree, but all of the other
writers refer to it as attaining large dimensions. Few reliable figures
of size are available. Sievers (43, p. 194) says that it reaches a
height of approximately 100 feet in the Maracaibo region. The present
writer has seen logs of this species in New York, transshipped from
Curaçao, that were from 14 to 20 inches in diameter and from 8 to 12
feet long. They were smooth, straight, cylindrical and free from knots,
indicating that they had come from rather tall trees. The bark was dark
gray, smoothish, with longitudinal wrinkles. The bark of a smaller stem
was very thin, of a gray-greenish color and showed fine longitudinal
wrinkling, crossed at right angles with numerous fine white lines.
Mr. H. M. Curran supplies the following information regarding this
tree in Venezuela: “Vera is a common tree of the dry foothills lying
between Porto Cabello and the Lake Maracaibo. It does not extend into
the extremely dry coastal hills and sand dune areas, but where a little
more moisture and better soils are found it is often a very prominent
feature in the vegetation. Perhaps four or five trees per acre may be
found over considerable areas though the stand would probably be less
than 1,000 board feet per acre. The tree as commonly met with is from
40 to 50 feet in height, slender, with a rather small branched crown
and is fairly straight, though many individuals are twisted. The tree
seldom makes a clear length of more than 15 or 20 feet. The flowers
are bright yellow, and the tree is quite ornamental when in bloom.
The fruits following the fall of the flowers are rather membranaceous
winged pods. The wood is hard, very durable, and is commonly used for
fence posts, telegraph poles, and durable construction in general.”
The wood of vera has many technical properties in common with the true
lignum-vitae (_Guaiacum_). In the specimens examined by the writer the
heartwood is more or less striped and banded, and varying in color
from light olive-green to chocolate-brown. The surface of fresh wood
often turns dark green upon exposure to the air and sun. The sapwood is
mostly thin and is light yellow except near the heart where the vessels
become green upon oxidation of their contents, thus giving a finely
striped effect. Generally the color is lighter than in _Guaiacum_.
One finds the same arrangement of pores as in _Bulnesia Sarmienti_
except that the radial lines are usually narrower and not so inclined
to branch. The specific gravity of the heartwood, as determined by the
writer on oven-dry material, varies from 1.11 to 1.21. J. Martinex
Espino (see 1, p. 178) gives 1.14 as the average density. The heartwood
is impregnated with the mildly scented resin typical of the woods of
this family.
The heartwood is very durable under exposure and will last indefinitely
in the ground. Mr. H. M. Curran found among the ruins of an old Spanish
fort on the tip of Araya Peninsula, Venezuela, a pole which was in
perfect preservation after some 300 years. A specimen of this wood was
examined by the writer and identified as the heartwood of _Bulnesia
arborea_. (For features distinguishing the woods of _Bulnesia_ and
_Guaiacum_ see page 19.)
Guaiacum
This genus, the source of the true lignum-vitae of commerce, is well
distributed over the islands and coastal regions of tropical North
America. The range in South America seems to be limited to the northern
fringe of coast and adjacent islands. Most of the commercial timber is
supplied by the West Indies;--Cuba, Haiti, Dominican Republic, Jamaica,
and the Bahamas. Considerable material is also obtained from the west
coast of Nicaragua.
_Description of Species_
At least six species[10] are recognized by botanists but very
little reliable information is available regarding their respective
ranges. There are two species in the West Indies, namely, _Guaiacum
officinale_ L. and _G. sanctum_ L.[11] The latter is a small evergreen
tree sometimes reaching a height of 30 feet with a small and stout
trunk, rarely 12 inches in diameter,[12] clothed with a thin pale
or white scaly bark. The slender pendulous branches are enlarged at
the nodes and somewhat furrowed. The ovoid, five-cornered fruit is
greenish-yellow to bright orange, the seeds dark brown or black and
covered with a scarlet exocarp. It is often cultivated for decorative
purposes on account of the beauty of its flowers and foliage. It grows
naturally in southern Florida, “abundantly on Upper Metacombe and
Lignum-vitae Keys and less commonly on Lower Metacombe and Umbrella
Keys” (40, p. 63), and is the only representative of the genus reaching
the United States. The species occurs throughout the West Indies and,
according to Vail and Rydberg (48, p. 106), grows naturally in Yucatan.
It has never been of great commercial importance because of its small
size and is still less so now than formerly. Flückiger (14, p. 101)
says of it: “It is found in southern Florida, the Bahama Islands,
Key West, Cuba, San Domingo (including the part called Hayti), and
Puerto Rico, and is certainly the source of the small but excellent
lignum-vitae exported from the Bahamas as well as some of that shipped
from Hayti.”
[10] For key to these species see Vail and Rydberg (48, p. 105).
[11] Varietal forms of _G. sanctum_ exist in Haiti, but have not been
described. According to Mr. C. D. Mell, one of these produces a large
timber tree, the bera or so-called bastard lignum-vitae of Haiti.
[12] Sargent (40, p. 63) gives maximum diameter of trunk as 2.5 to 3
feet.
The specific gravity of oven-dry wood of this species from Florida,
as determined by Sharples (see 39, pp. 268-9), varies from 0.9563 to
1.2736, average 1.1432. The variations are in part due to the presence
of more or less sapwood in some of the specimens. The specific gravity,
oven-dry, of a specimen from Florida was found by the writer to be 1.09
for the sapwood portion and 1.19 for the heartwood. The sapwood of
_Guaiacum sanctum_ is usually thicker than in _G. officinale_.
In longitudinal compression, the ultimate strength in kilos of two
specimens of Florida wood was found by Sharples (see 39, p. 420) to be
11,930 and 11,648, respectively. These values were somewhat in excess
of those for the best specimens of hickory but were materially exceeded
by some pieces of Osage orange, black locust, and some less common
woods. In resistance to indentation the wood of _Guaiacum sanctum_ is
given first rank (see 39, p. 253) among 405 woods tested, and is far
above any of the common woods of the United States.
_Guaiacum officinale_ is a low or medium-sized evergreen tree with a
thick bole often 10 to 12, occasionally 18 to 20, inches in diameter.
Its branches are crowded and flexuose and the pinnate leaves are
leathery. The fruits are two-cornered and yellowish, bearing seeds
light to dark brown with a cream-colored exocarp. Its range includes
all of the West Indies and the northern coast of South America,
especially Venezuela and Colombia. Schomburgk (42, pp. 850, 1,012) says
it is cultivated in gardens along the coastal region of British Guiana
and also grows in the forests along the Essequibo, where it reaches
tree size. No other reference to its occurrence in British Guiana has
been found. According to Vail and Rydberg (48, p. 106) the species
grows naturally in Panama, and Harshberger (21, p. 664) mentions it as
occurring in Honduras.
Oviedo (see 14, p. 101), who landed in America in 1514, mentions
this tree, under the name of “guayacan,” as a native. (This should
dispose of the claim of a Brazilian botanist (7, p. 81) that _Guaiacum
officinale_ L. was introduced into San Domingo from the Matto Grosso by
the Spaniards in 1508, and thereafter considered native there). Oviedo
appears to have been aware of two species, one of which he found in
Espanola (San Domingo) as well as Nagranda (Nicaragua), and the other
in the island of Sanct Johan (Porto Rico), whence it was called “lignum
sanctum.” This name is still in use, particularly for the wood of
_Guaiacum sanctum_.
Four Mexican or Central American species of _Guaiacum_ are described
by Vail and Rydberg (48, pp. 106-7), but very little is available
regarding their commercial importance and range. _G. guatemalense_
Planch. is said to be a small tree about 15 feet high with stems
clothed with somewhat corky bark. The flowers, which are azure blue,
appear before the new leaves; the fruit is reddish or orange, the seeds
reddish-brown. The type was collected on the hot plains of Zacapa,
Guatemala, and nothing further is known of its range.
_Guaiacum Planchoni_ A. Gray is said to be a much branched shrub, 6 to
10 feet high, with grayish corky bark, leaves crowded or fascicled on
short modified branchlets; flowers solitary. The type was collected
between Tehuantepec and the Pacific Ocean, Oaxaca.
_Guaiacum Palmeri_ Vail is, according to the same authorities, a shrub
or possibly a small tree, with leaves fascicled as in the preceding.
The fruit is yellowish-green, leathery, with seeds covered with a
dark-red (?) fleshy exocarp. The type was collected at Guaymas, Sonora.
_Guaiacum Coulteri_ A. Gray produces wood of value, though to what
extent is undetermined. This tree is known to occur all along the
western part of Mexico from Sonora to Oaxaca and it is possible that
the commercial lignum-vitae of Nicaragua and the east coast of Mexico
is supplied by this species. According to the botanists the tree is
small, often reduced to a shrub, with clustered blue flowers and with
greenish fruit containing brown seeds covered with a pale yellowish
aril.
Hemsley (22, p. 159) suggests the possibility of this and _G.
guatemalense_ Planch. being the same species, but the material at his
disposal was insufficient to decide the question.
In 1913, Dr. H. N. Whitford made an examination of the forest on Maria
Magdalena Island, the middle one of the Tres Marias group off the coast
of Tepic, Mexico. He found a tree called “guayacan” which was afterward
identified as _Guaiacum Coulteri_. In a manuscript report he says:
“This species is probably the lignum-vitae of commerce. It occurs
growing very scattered with the ‘palo prieto’ and on the flats near
the mouths of the arroyos. The trees are mostly small, between 8 and
12 inches in diameter, yielding logs from 6 to 10 feet in length. One
tree was 24 inches in diameter yielding a log only two feet long. It
had three branches 8 inches in diameter and 6 feet long that would make
good logs. The forests on the main coast are said to produce trees much
larger than those on the island. Guayacan is very hard, very durable
and very heavy. It is dark greenish-brown in color with concentric
rings of nearly black. It is very fine-grained.”
_Minute Anatomy of the Wood of Guaiacum_
The pores are circular or elliptical and are irregularly distributed,
being sometimes abundant and sometimes few and scattering. Usually no
definite arrangement can be noted, but occasionally they are in echelon
and in some cases a tendency to a ring-porous structure has been
observed. There may be considerable difference in the size of the pores
in the same specimen while in others they are fairly uniform. In a
piece of Cuban lignum-vitae, 14 of the largest pores were found to have
an average size of 0.15 × 0.11 mm.; the maximum was 0.18 × 0.14 mm. In
a specimen from Nicaragua the pores were nearly all small, the largest
measuring about 0.10 × 0.08 mm. The walls in both cases were about 0.01
mm. thick.
The vessel segments, wood fibers, wood parenchyma strands, and the
rays are in horizontal seriation. The bordered pits between contiguous
vessels are small, very numerous, and with rounded or hexagonal
outlines; the pits between the vessels and rays are small, numerous,
and half-bordered. The wood fibers are very thick-walled, very small,
short, crowded together without any definite arrangement, and provided
with numerous weakly bordered pits. The vessel segments are mostly 0.09
to 0.10 mm. in length, with simple perforations throughout, without
tyloses, but with abundant resin (in heartwood) which dissolves readily
in alcohol. The rays are from 1 to 8, mostly 5 or 6, cells high and
either uni-seriate throughout or two cells wide in the middle portion.
The individual cells are very small, thick-walled, sometimes containing
crystals, and commonly resinous. Wood parenchyma is present in varying
amount in association with the vessels, or diffused, or in tangential
lines of irregular length or sometimes in concentric bands several
cells wide apparently limiting growth rings. The variations in the
amount and arrangement of the parenchyma are very noticeable, not only
in different woods but also in different parts of the same specimen.
[Illustration: Cross section of Bulnesia arborea (Maracaibo) Note the
radial distribution of the pores]
[Illustration: Cross section of Guaiacum from Haiti Note irregular
distribution of the pores]
_Distinguishing Features of the Woods of Guaiacum and Bulnesia_
_Guaiacum_ _Bulnesia_
Pores irregularly disposed. Pores in radial arrangement. (See
(See opposite page.) opposite page.)
Pores often widely variable Pores small and fairly uniform in
in size; largest sometimes size; not individually distinct
visible without lens. without lens.
Pores mostly circular or oval. Pores often angular in outline.
Parenchyma paratracheal and Parenchyma paratracheal and
metatracheal; also often terminal diffuse; indistinct with lens.
in fine lines distinct with lens.
Crystals present but not abundant Crystals very abundant in wood
in wood parenchyma and rays. parenchyma and rays.
Rays mostly uni-seriate; Rays commonly 2-seriate
sometimes 2-seriate in middle (occasionally 3-seriate) in middle
portion. portion.
Essential oil not known to be Essential oil known to be present,
present. at least in one species.
Woods of the two genera are alike in being very dense, fine-textured,
cross-grained; dark brown or greenish in color with oily appearance
and feel; mildly and pleasantly scented when warmed; containing guaiac
resin with characteristic color reactions. Woods with very fine and
uniform ripple marks, invisible without lens, averaging about 250
per inch of length. These ripple marks are likely to be absent in
small twigs (0.5 cm. or less) such as one commonly finds in herbarium
material. The characteristic alternating or fine-roe grain was not
found in stems or twigs less than 1 cm. thick. The interlocked grain is
not due, as sometimes supposed, to the crossing of true right and left
hand spirals around the stem, but to a weaving back and forth of the
fiber layers in an irregular “lazy-S” manner up and down the trunk.
_Check List of Common Names_
_Guaiacum officinale_: Lignum-vitae (U. S.; general trade);
guaiacum-wood (England); holy wood, wood of life, Indian wood (Lit.);
guayacan, guaiacan, guayakan (Spanish); hoaxacan, lignum sanctum,
guayacan blanco (Porto Rico); guayacan negro, guayacan prieto, palo
santo (Cuba); gayac jaune vert (Martinique); bois de gaïac or bois
de gayac, bois sant (Fr.); Pockholz, Guaiacholz, Guajak, Guajakholz,
Franzosenholz, Lignum Sanctum-holz (Ger.); guaiaco nero, legno santo,
legno benedetto, legno nefritico, legno di guaiaco (Ital.); pokhout
(Dutch); guaiaco (Port.); “Congo cypress” (Brush-back trade).
_Guaiacum sanctum_: Lignum-vitae (America; general); Bahama
lignum-vitae (Eu. trade); palo santo, lignum sanctum, lignum
guaici (Spanish); vera, bera (Haiti); vera amarilla, vera prieta,
guayacancillo (Cuba); ironwood (Florida); guaiaco banco, legno santo,
legno benedetto (Ital.). The wood of this species is often not
distinguished from the foregoing and the same names may be used for
both.
_Guaiacum_ spp.: Lignum-vitae (Trade); guayacan, palo santo
(Mex.).
_Bulnesia arborea_: Vera, vera aceituna, vera amarilla, vera azul,
vera blanca, bera, berra (Venezuela, Colombia); Maracaibo lignum-vitae,
vera-wood (Trade); guayacan, palo sano (Colombia); gayac de Caracas
(Fr.); Vera-holz (Ger.); “Congo cypress” (Brush-back trade).
_Bulnesia Sarmienti_: Palo santo (Argentina); palo balsamo
(Trade); palo santo negro (Paraguay); páo santo (Port.).
_Bulnesia retamo_: Retama, retamo (Argentina).
_Porlieria angustifolia_: Guayacan.
_Porlieria Lorentzii_: Guayacan blanco (Argentina); cucharero,
chucarea, chukupi, chuchupi, chucupi (Indian names, Arg.).
_Porlieria hygrometrica_: Guayaco, palo santo (Chile); turucasa
(Peru).