Common Trees of Puerto Rico and the Virgin Islands

nal home unknown. Widely cultivated and nat- (Cuba) ; mel6n zapota (Mexico) ; papayo calenuralized
in southern Florida, Bermuda, through- tano (Colombia) ; lechosa, papaya (Venezuela) ;
out West Indies, from Mexico to Argentina and papayo, mam6n (Argentina) ; apaya, pawpaw,
Brazil, and in the Old World tropics. papaw (United States, ~nglis$ ; papaye, papa-
OTHER COMJION ~~~w.-papay, pawpaw (Vir- yer (French) ; papaya, papap, pa ay (Dutch :
gin Islands) ; papaya (Spanish) ; fruta bomba West Indies) ; mamiio, mamoeiro ( If razil).
CACTUS FAMILY (CACTACEAE)
Key to the 2 species illustrated (Nos. 175-176)
A. Branches columnar, with 7-11 ridges and grooves; fruits round, spineIess--175. Cephalocereus royenfl.
AA. Branches flat, oblong joints or pads; fruits pear-shaped, mostly spiny-176. Opuntia rubeecens.
175. Sebucgn, dildo Cephdocereus royenii (L.) Britton & Rose
This tree cactus of dry areas is easily recognized
by : (1) stout erect gray-green columnar branches
21/24 inches in diameter with 7-11 ribs, or ridges,
and grooves between the branches and trunk, not
woody but soft and succulent; (2) absence of
leaves, but with many clusters of several spreading
needlelike yellow to gray spines 943-234 inches in
length along the ribs; (3) ,penish, whitish or
purplish-tinged, flowers 2 inches or more in length,
tubular and fleshy with many sepals and petals,
borne singly and stalkless along ribs near apex;
and (4) rounded but much flattened edible red
berry up to 1 inch hi h and 2 inches in diameter,
the surface smooth an 3 spineless.
A branched cactus 6-20 feet tall with trunk 4-12
inches in diameter, commonly dividing at 1-2 feet
above the base into several branches. As twigs
and leaves are absent, there is no definite crown as
in other trees. The trunk is reddish brown,
smoothish except for rows of spines radiating in
clusters and with very thin bark, The surface of
the smooth grooves in the branches is covered with
a bloom at least when young.
The spinas are in clusters, several radiating out
from the central point of attachment (meole),
which also bears inconspicuous whitish hairs.
Near the rounded apex of branches the ribs bear
tufts of longer white hails about lyi inches in
length, which are woolly and somewhat shaggy.
The tubular fleshy flowers extend straight and
nearly horizontal, opening at night. The flower
has an inferior, smoothish, spineless rounded
ovary about M inch long, 1-celled; a funnelform
greenish fleshy tube (hypanthium) with many
overlapping oblong, rounded or pointed, whitish
or purplish-tinged, fleshy sepals about 9/8 inch long
and with about 10 whitish narrow pointed petals
3j-35 inch long within; very many white stamens
j/q--/2 inch long attached at the throat and base of
the tube; and protruding white fleshy style almost
2 inches long with many narrow stigma lobes.
The ovary develops into the fruit, while the remaining
flower arts shrivel and d ~ remaining ,
attached. The I attened berry contains red juic
flesh slightly sweet and edible and many sma rV 1
shiny black seeds less than '/lo inch long. Probably
flowering irreeularly through the year.
The trynk is composed mostly of soft waterstoring
tissues, light green near the surface and
ellowish within, juicy and slight1 salty in taste.
%he soft wood is a light brown X brous cylinder
with large white rays.
The tree cactus is remarkably well adapted to
very dry conditions. The root system is broad and
near the surface where water from light rains can
be absorbed rapidly. The bulk of the plant is
made u of water storage tissue, which retains
water a g sorbed after rains for use over long dry
periods. The surface area is greatly reduced
through absence of leaves, and loss of water to the
air (trans iration) is correspondingly checked.
The branc R es have a ve thick skin which also
retards evaporation and,fbein en, at the same
time carry on the processes o f !F' ood manufacture
(photosynthesis), normally functions of the fireen
leaves. Further, the formidable spines protect
the juicy stems from animal life.
Scattered in drg forest on plains and hills at
lower elevations in southern and southwestern
Puerto Rico and rare at Cape San Juan in the dry
extreme northeastern corner. Also on Mona,
Desecheo, Icacos, Culebra, and Vieques. Through
Virgin Islands on St. Cmix, St. Thomas, St. John,
Tortola, Vir 'n Gorda, Anegrtda, and probably
smaller islan P s.
PUBLIC ~on~s~4~6nica.
RANOE.-MO~~, Puerto Rim and smaller adja-
cent islands, Virgin Islands and St. Kith and
Antigua in northern Lesser Antilles.
OTHER COMMON NA~.-pipe-organ cactus,
cactus (Virgin Islands).
BOTANIOAL SYNONYMB.--C~~~~ royenii (L.)
Mill., Pilocerewr royenii (L.) Riimpl.