Kumquat

Kumquat

　　Also known as Jingju, the kumquat is a traditional local fruit of Guizhou Province, cultivated for over 350 years. Kumquats are small in size, typically weighing between 30 to 50 grams each, and come in round, flattened, or disc-like shapes. The fruits are found in orange-red, tangerine-red, and vermilion hues. Their rinds are distinctly oil-speckled, exuding a pure and fragrant aroma. This variety has a high fruiting rate, with evenly distributed fruits densely clustered across the inner and outer canopy, resembling small red balls that stand out strikingly against the dark green foliage. The kumquat’s peel is easy to remove, the carpels easily separated, and the juice vesicles are plump and juicy. The flesh appears in either cherry-red or beef-red colors. The fruit is high in sugar and low in acid; when eaten fresh, it is sweet, tender, and refreshing. When processed into preserves and juices, it takes on even more distinctive flavors.

　　Kumquat seedlings grown from seed often show many variations, with few exhibiting improved traits, and they bear fruit late. Therefore, they are not commonly propagated through seeding, but rather by grafting, cutting, or air-layering. For grafting, trifoliate orange, orange, or pomelo seedlings are used as rootstocks. Bud-grafting is done from late March to mid-April, bud grafting from June to July, and approach grafting from May to June, all with high success rates. Air-layering involves selecting strong branches from the kumquat plant, girdling them, and wrapping them with moist moss or peat to maintain humidity. Roots develop within a month, and after two months, the layered sections are cut off and potted individually. Cuttings are performed from April to August, using either hardwood or softwood cuttings, and are potted before the first frost once rooted and then moved into a greenhouse.

　　Ornamental Value

　　The kumquat tree has an attractive form, lush foliage, remains evergreen throughout the seasons, and bears golden fruits, making it a uniquely elegant choice among ornamental fruit-bearing plants. It is a must-have potted plant during the Chinese New Year for households in Guangdong, Hong Kong, and Macau.

　　Traditional Chinese Medicine Uses

　　【Also Known As】Luju (“The Book of Han”), Shanju (“Record of Northern Regions”), Jindan (“Wenzhou Annals”), also called: Jindanju (“Eight Notes on the Nurturing of Life”), Jindan (“Dietary Manual of Suixi”), Jinguo (“Return to Field Record”), also known as: Luofu (“Miscellaneous Chronicles of Ou River”), Milk Orange (“Eight Notes on the Nurturing of Life”), Milk Tangerine (“Flower Mirror”), Jujube Orange (“Hundred Hymns of Flower Calendar”), Longjin Gan, Shouxing Gan.

　　【Source】The fruit of the kumquat or golden kumquat plants in the Rutaceae family.

　　【Plant Morphology】An evergreen shrub or small tree, growing up to 3 meters tall. Branches are densely packed, usually spineless. Leaves are alternate; blade shape is long-elliptic, lanceolate, or oblong, 4–8 cm long, 2–3 cm wide, with a blunt or slightly acuminate tip, undulate or faintly serrated margins, wedge-shaped base, and densely glandular beneath; petioles are 0.5–1 cm long with narrow wings. Flowers are solitary or grow in clusters of 2–3 in leaf axils of new shoots; pedicels are 3–5 cm long, with flowers about 1.5 cm in diameter; sepals are 5, green; petals are 5, white, narrowly oblong, reflexed, about 7 mm long; stamens are 20–25, basally irregularly fused into several bundles; pistil is 1. The citrus fruit is an oblong or long oval, 2–3.5 cm long, rounded at the apex, with a persistent style; the peel is smooth, glossy, golden-yellow when ripe, thick, and densely glandular; the carpels are 4–5 lobed, juicy and sour. Flowering occurs in June. Fruits ripen in December.

　　【Chemical Components】Both the fruits and petals of the kumquat and golden kumquat contain kumquat glycosides, with 80% of the vitamin C in kumquat fruits found in the peel.

　　【Material Sourcing】In addition, Fortunella japonica (recorded by Han Yanzheng in “The Citrus Record,” also called round kumquat), a member of the same genus, has narrower leaves; its fruits are round, with thin peels and 5–6 carpels. It is also used medicinally. The roots (kumquat root), leaves (kumquat leaf), and seeds (kumquat seed) of these plants are also used in medicine—each detailed in their respective entries.

　　【Functions】Phlegm resolving and cough suppressing, qi regulating and depression relieving. Indicated for: inhibited lung qi, coughing with phlegm; liver and stomach qi stagnation, chest and rib distension, reduced appetite, etc.

　　【Properties and Channels】Tastes sweet, sour, and acrid; nature is slightly warm. Enters the lung, stomach, and liver meridians.

　　【Usage】Preserved in honey, sugared and pickled, eaten raw, brewed into tea, or decocted into soup.

　　【Application Examples】1. Chewing kumquats is used for coughs with phlegm and whooping cough. For cold-induced coughs, crush the fruit, soak it with ginger in boiling water, and drink the infusion; for heat-induced coughs, extract the juice of kumquats with radish and consume. 2. Eating fresh kumquats raw or preserved in honey, or decocting them with hawthorn and malt, helps with food stagnation and qi obstruction, abdominal bloating, and poor appetite. 3. Using only honey-preserved kumquats, or steeping them with Buddha’s hand and Daidai flowers in boiling water, adding sugar for flavor, helps with liver qi stagnation, chest and rib distension or pain.