Biology:Juniperus chinensis

Short description: Species of conifer

Juniperus chinensis
Chinese juniper shoot, showing juvenile (needle-like) leaves, adult scale leaves, and young male cones
Conservation status
Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Gymnospermae
Division:	Pinophyta
Class:	Pinopsida
Order:	Cupressales
Family:	Cupressaceae
Genus:	Juniperus
Section:	Juniperus sect. Sabina
Species:	J. chinensis
Binomial name
Juniperus chinensis L.

Juniperus chinensis, the Chinese juniper (圆柏, 桧) is a species of plant in the cypress family Cupressaceae, native to China, Myanmar, Japan, Korea and the Russian Far East. Growing 1–20 metres (3 ¹⁄₂–65 ¹⁄₂ feet) tall, it is a very variable coniferous evergreen tree or shrub.

The Juniperus chinensis is one of the top species used in the Japanese art of bonsai, referred to as "Shimpaku." Among the multiple cultivars of Shimpaku found in Japan, the most desirable due to its tight, fine foliage and excellent growing habits, is the "Itoigawa" variety.

Juniper bonsai grafted with Itoigawa foliage. This tree is estimated to be 150-250 years old

Growth

The leaves grow in two forms, juvenile needle-like leaves 5–10 millimetres (¹⁄₄–³⁄₈ inch) long, and adult scale-leaves 1.5–3 mm long. Mature trees usually continue to bear some juvenile foliage as well as adult, particularly on shaded shoots low in the crown. This species is often dioecious (either male or female plants), but some individual plants produce both sexes of flowers. The blue-black berry-like cones grow to 7–12 mm in diameter, have a whitish waxy bloom, and contain 2–4 seeds; they mature in about 18 months. The male cones, 2–4 mm long, shed their pollen in early spring.

Cultivation and uses

This popular ornamental tree or shrub for gardens, parks, and in tough coastal conditions of hot sun and sandy fast-draining soils, has more than 100 named cultivars selected for various characteristics, such as yellow foliage (e.g. cvs. 'Aurea', 'Tremonia'), permanently juvenile foliage (e.g. cv. 'Shoosmith'), columnar crown shape (cv. 'Columnaris'), abundant cones (e.g. cv. 'Kaizuka'), etc. First popular in the United States in the Los Angeles gardens in Mediterranean style homes, and now commonly found along both the West and East Coast in beach and coastal areas.

The Chinese juniper is widely used in bonsai, both as individual plants, such as the 250-year-old "Omiya tree" in the Birmingham Botanical Gardens in the United Kingdom , and in groups, such as the well-known Goshin on display at the National Bonsai and Penjing Museum at the US National Arboretum. The cultivar 'Shimpaku' is a very important bonsai subject.

AGM cultivars

The following cultivars have gained the Royal Horticultural Society's Award of Garden Merit:-

• 'Aurea' (golden Chinese juniper)
• 'Blaauw'
• 'Grey Owl'
• 'Kaizuka'
• 'Plumosa Aurea'
• 'Pyramidalis'

Juniperus × pfitzeriana

The hybrid between Juniperus chinensis and Juniperus sabina, known as Juniperus × pfitzeriana (Pfitzer juniper, synonym J. × media), is also very common as a cultivated plant. This hybrid grows only as a shrub, never a tree, making it suitable for smaller gardens:-

• 'Old Gold'
• 'Sulphur Spray'

Gallery

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  As a 250 year old bonsai in the Birmingham Botanical Gardens

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  J. × pfitzeriana 'Old Gold'

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  J. chinensis 'Expansa Variegata'

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  Juniperus chinensis var. kaizuka

References

Wikidata ☰ Q157697 entry