Common Trees of Puerto Rico and the Virgin Islands

CASHEW FAMILY (ANACARDLACEAE)
Key to the 6 snecies illustrated (Nos. 130-1353
A. Leaves simple.
B. Leaves elliptic or obvate, rounded at both ends or slightly notched at apex-130. Anacardium occidentale.
BB. Leaves Iancesha~ed. - , 1on~-minted -- at both ends-131. dfangtfwa -. indica.*
Ah. Leaves pinnate.
C. Leaflets usually 5 (3-7), orate, blunt-pointed or minutely notched at apex; sap poisonous to the touch-132.
Metopium toaiferum.
CC. Leaflets 9-25.
D. Leaflets mostly lance-shaped, long- or short-pointed at apex, with short stalks about % inch long.
E. Leaflets inconspicuously toothed-133. Spondiaa d~lci.8.~
DE. Leaflets not toothed-134. Sponcliaa mombin.
DD. Leaflets elliptic, rounded or short-pointed at apex, almost stalkless-135. Spottdias ptrrpurea.*
130. Pajuil, cashew Anacardium occidentale L.
Known for its cashew nuts and fruits, this small
tree of sandy areas on the north coast of Puerto
Rico, sometimes planted, is ident,ified by: (1) :I
dense irregular crown of obovate or elliptic, dull
blue-green, leathery leaves 2%-6 inches long and
13/44 inches broad, rounded at both ends or slightly
notched at apes, the edges turned under
and with prominent sunlren lateral veins nearly
at ri~ht angles to the midrib; (2) many fragrant
pinkish flowers about s/s inch long, with 5 very
narrow petals, short-stalked and crowded toward
ends of terminal branched clusters; and (3) the
very odd fruits consistin of a shiny gray-brown
kidney-shaped or bean-s 7 aped nut (edible only
when roasted), about 1-1% inches long on a yellow
or reddish, fruitlike, enlarged, pear-shaped
stalk or false fruit about 1yL-3 inches long and
1%-2 inches broad, juicy and edible, thus appearing
as if the nut grows outside the fruit. The nut
shell contains a caustic poisonous oil which blisters
or burns the skin.
An ever een tree to 20 feet hi h and 6 inches
in trunk f lameter, or often shru k by. The light
ay to brown bark is smoothish, becoming slightly
Eured. The n~llitish to reddish-brown inner bark
is thick, bitter, and astringent, and contains a
milky juice, and larger trunks ield a gum. Twigs
are yellow green and finely 3 miry when young,
becoming light gray, stiff, and crooked.
The alternate leaves have broad yellow-green
petioles l/q-1/2 inch long. Leaf blades slightly
thickened, pale beneath.
The widely spreading flower clusters (panicles)
are 4-10 inches long and nearly as broad. Flowers
are male and bisexual on the same tree (poly -
amous). Calyx is more than inch long, lig f t
green and finely hairy, narrowly 5-lobed nearly
to base; the 5 pinkish petals yellow green at first
are 3/S-1/2 inch long, long-pointed,. spread]
curved backward, and minutely hnlry ; 10 or '9 ewer and
stamens, 1 much lo~!ger than the others, slightly
united at base; and In bisexual flowers a pistil on
a disk with 1-celled ovary and slender curved
style on 1 side.
The nuts, which are the truo fruits, are attached
at end, dry, and do not split open. Inside the
oisonous shell is 1 large curved seed nearly 1 inch
lbng, the edible cashew nut. As the nut matures,
286
the stalk (receptacle) nt base enlar es rapidly
within n few days into a flesh fruitlib structure
bronclest at apex, popularly E nown as the fruit.
This thin-skinned edlble cashew "fruit" has light
yellow spongy flesh, which is very juicy and pleasantly
acid and slightly astringent when eaten mw
but highly wtrin ent when green. Flowering
fro111 February to%ay, the fruit maturing fmnl
April to August.
The wood is whitish, brownish, or pinkish, of
medium hardness, medium\\-eight (specific gravity
0.5), lnoderately strong, and easy to work but
susceptible to attack by dry-mood ternlites.
Though little used in Puerto Rico, the 11-oocl has
been employed elsewhere locally in constr~lction
and carpentry, including botitbuilding, yokes,
hubs, etc., and for charcoal. Tl~e bark hns served
in tanning. Mucilage repellent to insects and varnish
have been made from t,he gum, n~l~icll is
similar to gum arabic, and an indelible ink fro111
the milky sap.
The tree is valued pri~narily for the nuts and
fruits. Roasted cashew nuts are an item of world
commerce. In roasting, the poisonous oil of the
shell is removed by heat, but bhe caustic fumes
and drops of oil may blister the skin and inflame
the eyes if care is not exercised. The "fluits" are
eaten fresh or in preserves and have been emplo
ed in preparation of wine and vinemr.
drdol oil, the poisonous, thick, black, very acrid
oil of the shell of the nut, has been used medicinally
and to preserve book bindings, carved mood,
and silnilar articles against insects. 11 nutritious
oil similar to olive oil has been obtaiiletl from the
seeds. The barlr has been the source of lnedicines
t~lso. As the flowers are attrrictive to bees, this
s ecies has been classed also among the honey
p P ants.
Living fences have been m:tde from the trees,
which sometimes are grown for ornament. The
plants mature at a very early age and are shortlived,
flowering and fruitin as early as the second
or third or sometimes the i? rst year after sowing.
Through the tropics the trees are grown in plantations
for the nuts and "fruits," but they are semiwild
or naturalized in many regions. In the Virgin
Islands the trees are uncomlnon but widely
planted for shade and fruit, such as around houses,