''Juniperus procumbens'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

of shrub in the cypress

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Cupressaceae,

native Native may refer to: People * Jus soli, citizenship by right of birth * Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory ** Native Americans (disambiguation) In arts and entert ...

to Japan. This low-growing

evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, whic ...

conifer Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All ext ...

is closely related to the Chinese juniper, ''

Juniperus chinensis ''Juniperus chinensis'', the Chinese juniper (圆柏, 桧) is a species of plant in the cypress family (botany), family Cupressaceae, native species, native to China, Myanmar, Japan, Korea and the Russian Far East. Growing tall, it is a very va ...

'', and is sometimes treated as a variety of it, as ''J. chinensis'' var. ''procumbens''.

Description

It is a

prostrate shrub A prostrate shrub is a woody plant, most of the branches of which lie upon or just above the ground, rather than being held erect as are the branches of most trees and shrubs. Background Prostration may occur because the supporting tissues in ste ...

, usually growing tall, occasionally ; while it does not get very tall it can get quite wide, across or more, with long prostrate branches. The branches tend to intertwine and form a dense mat. The

leaves A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...

are arranged in

decussate Decussation is used in biological contexts to describe a crossing (due to the shape of the Roman numeral for ten, an uppercase 'X' (), ). In Latin anatomical terms, the form is used, e.g. . Similarly, the anatomical term chiasma is named af ...

whorls of three; all the leaves are juvenile form, needle-like, long and 1–1.5 mm broad, with two white

stoma In botany, a stoma (from Greek ''στόμα'', "mouth", plural "stomata"), also called a stomate (plural "stomates"), is a pore found in the epidermis of leaves, stems, and other organs, that controls the rate of gas exchange. The pore is bo ...

tal bands on the inner face. It is

dioecious Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproducti ...

with separate male and female plants. The

cones A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex. A cone is formed by a set of line segments, half-lines, or lines conn ...

are berry-like, globose, 8–9 mm in diameter, dark blackish-brown with a pale blue-white waxy bloom, and contain two or three

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosper ...

s (rarely one); they are mature in about 18 months. The male cones are 3–4 mm long, and shed their pollen in early spring. It produces cones of only one sex on each plant.Gymnosperm Database
''Juniperus procumbens''
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Distribution

The status of ''Juniperus procumbens'' as a wild plant is disputed. Some authorities treat it as

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to high mountains on

Kyūshū is the third-largest island of Japan's five main islands and the most southerly of the four largest islands ( i.e. excluding Okinawa). In the past, it has been known as , and . The historical regional name referred to Kyushu and its surround ...

and a few other islands off southern Japan,Farjon, A. (2005). ''Monograph of Cupressaceae and Sciadopitys''. Royal Botanic Gardens, Kew. while others consider it native to the coasts of southern Japan (north to

Chiba Prefecture is a prefecture of Japan located in the Kantō region of Honshu. Chiba Prefecture has a population of 6,278,060 (1 June 2019) and has a geographic area of . Chiba Prefecture borders Ibaraki Prefecture to the north, Saitama Prefecture to t ...

) and also the southern and western coasts of

Korea Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic ...

Cultivation and uses

Several

cultivar A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture ...

s have been selected, the most widely grown being 'Nana', a slow-growing procumbent plant,Welch, H. & Haddow, G. (1993). ''The World Checklist of Conifers''. which in the UK has gained the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (Nor ...

’s Award of Garden Merit. Others include 'Bonin Isles', a strong-growing mat-forming plant collected on the

Bonin Islands The Bonin Islands, also known as the , are an archipelago of over 30 subtropical and tropical islands, some directly south of Tokyo, Japan and northwest of Guam. The name "Bonin Islands" comes from the Japanese word ''bunin'' (an archaic read ...

, and 'Green Mound', which may just be a renaming of 'Nana'. A variegated plant sold under the name ''J. procumbens'' 'Variegata' is actually a cultivar of ''J. chinensis'' misnamed.

References

External links

Conifers Around the World: Juniperus procumbens - Japanese Mat Juniper
{{Taxonbar, from=Q658749 Plants used in bonsai procumbens Least concern plants Flora of Japan Flora of South Korea Dioecious plants