Clerodendrum japonicum

Clerodendrum japonicum

Japanese glory bower or red glory bower (Clerodendrum japonicum (Thunb.) Sweet, 1826) is a shrubby species belonging to the Lamiaceae family.

Sistematica –
Domain Eukaryota,
Kingdom Plantae,
Division Magnoliophyta,
Class Magnoliopsida,
Subclass Asteridae,
Order Lamiales,
Family Lamiaceae,
Subfamily Ajugoideae,
Genesere Clerodendrum,
Species japonicum.
The term is a basionym: Volkameria japonica Thunb.
The terms are synonymous:
– Clerodendrum squamatum Vahl (1791);
– Volkameria kaempferi Jacq. (1794);
– Clerodendrum kaempferi (Jacq.) Siebold (1830);
– Volkameria dentata Roxb. (1832);
– Clerodendrum dentatum (Roxb.) Steud. (1840);
– Clerodendrum coccineum D.Dietr. (1842);
– Clerodendrum kaempferi (Jacq.) Siebold ex Hassk. (1844);
– Volkameria coccinea (D.Dietr.) Schauer (1847);
– Clerodendrum imperialis Carrière (1874);
– Clerodendrum illustre N.E.Br. (1884);
– Clerodendrum darrisii H.Lév (1912);
– Clerodendrum esquirolii H.Lév. (1912);
– Clerodendrum speciosum Teijsm. & Binn. ex Wigman (1912);
– Clerodendrum leveillei Fedde ex H.Lév. (1915);
– Clerodendrum coccineum H.J.Lam (1919).
Within this species the following subspecies and varieties are recognized:
– Clerodendrum japonicum subsp. album C.Pei;
– Clerodendrum japonicum subsp. japonicum;
– Clerodendrum japonicum var. bethuneanum (H.Low) Wearn & Mabb.;
– Clerodendrum japonicum var. japonicum.

Etymology –
The term Clerodendrum comes from the combination of the Greek terms “κλῆρος” (cleros), meaning fate, and “δένδρον” (dendron), meaning tree, a name given by Johannes Burman (1707-1780) and taken up by Linnaeus, to a plant that in Sinhalese was called “pinnacola”, meaning unlucky.
The specific epithet japonicum is the Latin adjective “japonicus, a, um”, meaning of Japan, in reference to the supposed place of origin.

Geographic Distribution and Habitat –
Clerodendrum japonicum is a plant native to a vast area that includes: Arunachal Pradesh, Assam, Bangladesh, Borneo, Bhutan, China (Anhui, Chongqing, Fujian, Guangdong, Guanxi, Guizhou, Henan, Hong Komg, Hubei, Hunan, Jiangsu, Jiangxi, Kin-Men, Macao, Ma-tsu-Pai-chúan, Shanghai, Sichuan, Tibet, Yunnan and Zhejiang), Darjiling, Philippines, Java, Andaman Islands, Laos, Peninsular Malaysia, Nepal, Sikkim, Singapore, Sumatra, Taiwan, Thailand and Vietnam.
Its habitat in these areas is that of scrublands, grassy clearings and the banks of watercourses up to about 1500 m altitude (1600 m in Nepal).

Description –
Clerodendrum japonicum is a plant that grows in the form of a deciduous or semi-deciduous perennial shrub, erect, up to 3 m tall, with branches of an almost quadrangular section, more or less pubescent.
The leaves are carried by a 1-15 cm long petiole densely covered with short brown-yellowish hairs, they are opposite, simple, cordate with a pointed apex and toothed edges, 10-35 cm long and 6-25 cm wide, wrinkled above, dotted below with orange-colored glands.
The inflorescences are panicles and grow in a terminal position or in the axil of the upper leaves, on a reddish peduncle about 6 cm long, pyramidal, up to about 35 cm long, with a reddish rachis and a multitude of hermaphroditic flowers, on a pedicel up to 2 cm long, with a red bell-shaped calyx 1-1.5 cm long deeply incised into 5 ovate-lanceolate lobes, a bright red corolla, with a tube 1.5-2 cm long and 5 oblong lobes 1-1.5 cm long, a quadrilocular ovary and 4 curved stamens 4-7 cm long. The fruits are globose drupes with 4 lodges, about 1 cm in diameter, blackish blue when ripe, with persistent calyx lobes.
Inside there are 4 seeds, therefore one for each lodge.

Cultivation –
Clerodendrum japonicum is a plant that is sometimes collected in the wild for local use as food and medicine. It is sometimes cultivated locally for medicinal use or as an ornamental plant in gardens. It can also be used as a pioneer plant in the restoration of native habitats.
In its natural state it is widespread in a large area of ​​south-east Asia, but relatively little used as an ornamental in parks and gardens, cultivable in regions with tropical and subtropical climates and marginally in temperate-warm ones, where it can withstand exceptional drops in temperature just below 0 °C, with possible damage to the aerial part. It is therefore not a very cold-resistant plant, being able to tolerate short periods in which temperatures drop to around -3 °C.
For cultivation it requires a position in full sun and sheltered from the winds and is not particularly demanding regarding the soil, as long as it is well-drained, kept almost constantly moist.
The plant can be grown in pots for the decoration of particularly bright greenhouses and winter gardens using a substrate rich in organic substance with the addition of sand or agriperlite for 30%, with regular watering in summer, more spaced out in winter, allowing the soil to dry partially before watering again, and minimum winter night temperatures not lower than 14 °C.
The flowers are produced during the growth of the current season and therefore, to encourage flowering, it is best to carry out any pruning when the plant is dormant.
In some areas it can escape cultivation and become invasive.
Reproduction occurs by seed, in sandy soil kept moist at a temperature of 22-24 °C, with germination in 4-10 weeks; the young plants, when they are large enough to be handled, should be transplanted into individual pots and grown until they are large enough to be planted.
Reproduction can also be by cutting. The cuttings must be rooted, 6-8 cm long and have a high percentage of rooting.
Another asexual reproduction system is by division of suckers in the dormant season. It is a very simple system and they can be planted directly in their permanent positions if necessary.

Uses and Traditions –
Clerodendrum japonicum is a plant known by various common names, among these we remember: Japanese glory bower, red glory bower (English); cheng thong, he bao hua (China); chirinto (Japan); asara, kuthap angangba (India); patlange, igbo (Nepal).
The leaves of this plant are consumed locally as a vegetable, leaves and roots are used in traditional Chinese medicine for various pathologies.
The plant has medicinal uses and is used in various ways, including decoctions, gonorrhea, hematochezia, epistaxis, hematuria, for painful joints, blennorrhea, leucorrhoea, metritis, menstrual disorders, jaundice, furunculosis, impetigo, antralgia, osteodynia, lumbago, hypertension and other treatments or pathologies.
The leaves are antibacterial, anti-inflammatory, diuretic.
Among other uses we remember the agroforestry ones. This species is an early successional colonizer of degraded lands and could be used for habitat restoration.
The plant is classified as “least concern” in the IUCN Red List of Threatened Species (2018).

Preparation Method –
Clerodendrum japonicum is used for ornamental and agroforestry purposes as well as in food; the young leaves and shoots are cooked as a vegetable or pickled.
The leaves of species in this genus are usually bitter in taste and are often eaten at least as much for their tonic effect on the digestive system as for any attraction to the taste buds.
In the medicinal field, a decoction of the inflorescence is used in the treatment of gonorrhea, hematochezia and epistaxis.
The flower bracts are chewed as a treatment for hematuria and are applied as a poultice to painful joints.
The leaves are antibacterial, anti-inflammatory, diuretic.
A decoction is used in the treatment of a number of conditions including blennorrhea, leucorrhoea, metritis, menstrual disorders, jaundice, furunculosis, impetigo, antralgia, osteodynia, lumbago and hypertension.
An infusion of the leaves is used as a tonic during pregnancy.
The leaves are applied topically to boils.
The juice of the leaves is an ingredient in an herbal bath for children with boils.
A poultice of crushed fresh leaves and also washing with the leaf juice are used to treat wounds, burns, boils and impetigo.
The root is said to have been used successfully in the treatment of jaundice.
The root decoction is prescribed for chest disorders.

Guido Bissanti

Sources
– Acta Plantarum – Flora delle Regioni italiane.
– Wikipedia, the free encyclopedia.
– Useful Tropical Plants Database.
– Conti F., Abbate G., Alessandrini A., Blasi C. (eds.), 2005. An annotated checklist of the Italian vascular flora, Palombi Editore.
– Pignatti S., 1982. Flora d’Italia, Edagricole, Bologna.
– Treben M., 2000. Health from the Pharmacy of the Lord, Advice and experiences with medicinal herbs, Ennsthaler Editore.

Photo source:
– https://inaturalist-open-data.s3.amazonaws.com/photos/450998464/original.jpeg

Warning: The pharmaceutical applications and alimurgic uses are indicated for informational purposes only, they do not represent in any way a medical prescription; therefore, any responsibility for their use for curative, aesthetic or nutritional purposes is declined.