Common Trees of Puerto Rico and the Virgin Islands

RUE FAMILY (RUTACEAE)
97. Naranja agria, sour orange Citrus aurantium L.*
Sour orange differs from the other citrus fruits
in: (1) the round orange or reddish-orange fruit
21/2-41/2 inches in diameter, often broader than
long, more or less roughened, with thick peeling,
and hollo~~ pulpy core, ~vhich is bitter and too sour
to be edible; (2) strongly fragmnt large white
flowers with usually 5 petals; and (3) leaves ovate,
more or less long-pointed at apex and tapering or
rounded at base, the petioles wit11 broad wings
3/g-5/g inch across.
A small aromatic evergreen tree 15-30 feet high,
with rounded crown. The bark is brown and
smoothish, the inner bark light brown and bitter.
Twigs green, angled when young, with sliarp
spines becoming 1 inch long.
Leaves are alternate on petioles 3/q-11, inches
long. Blades are jointed with petiole, &ate, 21,-
514 inches long and 11/24 inches wide, ~vith many
mlnute rounded teeth at edges, n little leathery,
with numerous tiny gland dots, above green and
slightly shiny, and beneath pale light green. The
leaves have a pleasant scent.
There are 1 to few fragrant large white flowers
at base of n leaf. Calyx is light green and 4-5-
toothed ; usually 5 narrowly oblong white gland-
dotted petals about 3/q inch long; 20-24 stamens
united into tube in lower half; and pistil on a disk
with 9-12-celled ovary, style, and rounded stigma.
The fruit (berry or hesperidium) rind, lh-Y8
inch thick, is bitter and aromatic, and the flesh has
bitter lvalls. The whitish seeds are flattened,
markecl \\-it11 ridged lines, and about 1/2 inch long
(1,600 to a pound). Flowering throughout the
year.
The heartwood is whitish to light yellow, hard
and fine-pined, with prominent growth rings.
It is reported that the mood is like that of sweet,
orange or chinu (Citrus #inensix L.') and perhaps
is suitable for the same purposes. In Cuba thc
wood is used to make baseball bats.
The peeling with pulp of this species is the principal
source of orange marmalade and is sometimes
cnndied and, \\.hen fresh, yields an essential oil.
The juice serves for seasoning foods, such as soups
and meats, and sometimes as an orangeade drink
lien sweetened wit11 sugar. A perfume, oil of
neroli, is produced in southern Europe from the
petals. In home medicines the juice is an antiseptic
and hemostatic, and a decoction of the leaves
induces sweating. The peel and its oil have been
used medicinally as a source of vitamins. This
is n honey plant also.
Being resistant to the root rot disease of citrus
fruits, t,his species is employed, especially in t.he
United States, as the stock for budding the other
species.
Cult.ivated in Puerto Rico and spontaneous after
plant,ing and naturalized, chiefly in the Ion-er
inount.ain and moist limestone forest regions. A
hybrid or variety of the Seville ornnge, which has
sweet juice, is grown in Puerto Rico also. St.
Croix, St. Thomas, and probably - others of the Virgin
Islands.
Puu~rc FORESTS.-Carite, Guajataca, Luquillo,
Rio Abaio. Toro Nem.
~anai.L~ative 07 southenstern Asia. Widely
planted and naturalized in tropical and subtropical
regions. Naturalized in southeastern United
States (Georgia and Florida), Bermuda, through
West Inclies, and from Mexico to Argentina.
OTIIER COB~MON ~~~~s.-narnnja agria, naranja
ricidn (Spanish) ; naranjn cajera (Venezuela) ;
nsran jo amargo (Argentina) ; sour orange, Seville
oixnge (United States, English) ; bitter orange
(Bermuda, Jamaica); bi rade orange (Jamaica)
; orange sere (~aitiK orange siire, orange
amere, orange psse-peau (Guadeloupe) ; his
cl'oranger, namnga (French Guiana) ; laraha,
lanlla zier (Dutch West Indies) ; laranja da term,
laranja nmnrga (nrazil) .
I~OTANICAL SYNONYJLS.-~~~TU~ VU~~U& Risso,
0. bigaradia Loisel.