In the Fullerton Arboretum

by: Alfredo Chiri

WAMPEE - Clausena lansium var. 'Kua Pan' - Rutaceae
Donated by: CRFG/Tom and Glenda Ponder and planted in 1999 (r.f.-01)

Common names: Wampi, huang-p¹i-kuo, wang-pei, huampit, galumpi, hong bi,
hoang bi, som-ma-fai

The wampee is a distant relative of the citrus fruits and is native to
southern China and the northern and central provinces of Vietnam. The plant
was introduced to the USA in 1914 and has been growing in Florida. Some
varieties are being introduced to California, and they seem to be
The tree¹s growth depends on its location; it can be fast growing or slow.
The tree is an evergreen shrub to 15 feet, with upward slanting and flexible
branches. The bark is rough to the touch. The leaves are arranged in a
spiral form and are elliptic ovate from 2 to 4 inches.
The flowers are whitish or yellow-green, about 1/2 inch wide and borne in
slender panicles of 4 to 20 inches long.
The fruits hang in loose clusters at the end of several strands, and can be
round or oblong. The thin but tough rind is a light brown with very tiny
raised brown oil glands. It is easily peeled. The flesh is divided into
segments and is yellowish or colorless, juicy, sweet, somewhat grape like
and can be sub acid or sour. The fruit has 1 to 5 oblong seeds of a bright
green color with a brown tip.
The tree is considered to be subtropical to tropical, and young and mature
plants have been found to be tolerant to 28º F, but they will be killed at
temperatures below 20º F.

The plant seems to be tolerant to a wide range of soils, including deep sand
and limestone soils, but thrives in rich loam soils. Good drainage is
essential and it requires watering during dry periods.

The Wampee grows readily from seeds, which germinate in a few days. It can
also be grown from softwood cuttings, air layering, and be veneer grafted
onto wampee seedlings. There have been trials to propagate the wampee with
various rootstocks, but some will work while others will not. Seedlings
begin to bear fruits when 5 to 8 years of age.
The fruits ripen in July and August in the eastern USA, but not until
November in the western states. Mature trees may yield 100 lbs. of fruits
in a season. 
There are other varieties, and they vary somewhat in general
characteristics. The most common varieties planted throughout the world are:
Niu Shen', Yuan Chung', Yeh Sheng', Suan Tsao', Hsiao Chi Hsien', Chi Hsin'
and Kua Pan.