''Cephalotaxus harringtonia'', commonly known as Japanese plum-yew,
Harrington's cephalotaxus, or cowtail pine, is a
conifer
Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single ...
ous bush or small tree in the family
Taxaceae
Taxaceae (), commonly called the yew family, is a coniferous family which includes six extant and two extinct genera, and about 30 species of plants, or in older interpretations three genera and 7 to 12 species.
Description
They are many-bran ...
. It is native to
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
, but is occasionally utilised in western gardens and 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 exist for these purposes. Japanese plum yew has been in cultivation in Europe since 1829, and many modern horticulturists are familiar with this Japanese species, named in honor of
Charles Stanhope, 4th Earl of Harrington
Major-General Charles Stanhope, 4th Earl of Harrington (8 April 17803 March 1851), styled Viscount Petersham until 1829, was an English peer and man of fashion.
Petersham, the 3rd Earl of Harrington's eldest son, was a Regency era buck. He was e ...
, one of the first to grow the plant in a European garden, at Elvaston.
Description
New shoots of ''C. harringtonii'' remain green for three years after forming and have ribs at the leaf bases. The
bud
In botany, a bud is an undeveloped or embryonic shoot and normally occurs in the axil of a leaf or at the tip of a stem. Once formed, a bud may remain for some time in a dormant condition, or it may form a shoot immediately. Buds may be spec ...
s are green in colour, globular in shape and very small at only 1 mm in length. There is one rank of leaves present on either side of the shoot, and these rise up above it and curve slightly inwards, forming a narrow V-shape somewhat akin to a
dove
Columbidae () is a bird family consisting of doves and pigeons. It is the only family in the order Columbiformes. These are stout-bodied birds with short necks and short slender bills that in some species feature fleshy ceres. They primarily ...
's wings. The ranks are often vertical, but can be more flattened in shaded parts. The
leaves
A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...
are broadly linear in shape and measure about 5 cm long by 0.3 cm wide. They are abruptly pointed at the apex, leathery in texture and a bright matte yellowish-green on the upper-surface. The abaxial surface, or underside of the leaves, shows two broad, pale to silvery
stomata
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 bor ...
l bands.
The species 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 reproductio ...
and the male plants are typically densely covered with pairs of flowers that are pale cream in colour, though they become brown with time, and globular in shape. They are borne on 2 to 4 mm stalks beneath each pair of leaves.
Pollen
Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophyt ...
is released from March until May. The female individuals have two pairs of knob-like globose flowers that appear on curved stalks at the bases of the shoots. The fruit is obovoid in shape and measures 2.5 cm long by 1.5 cm wide. They are a smooth and pale green ín colour with dark green stipes, though when ripe they turn brown.
Taxonomy
The Japanese plum yew was first considered to be a
yew when it was partially described by
Thomas Andrew Knight
Thomas Andrew Knight (1759–1838), FRS, of Elton Hall in the parish of Elton in Herefordshire (4 miles south-west of Ludlow) and later of Downton Castle (3 miles north-west of Elton), was a British horticulturalist and botanist. He served as ...
in 1839 and as such was named ''Taxus harringtonii''. It was reclassified by
Philipp Franz von Siebold
Philipp Franz Balthasar von Siebold (17 February 1796 – 18 October 1866) was a German physician, botanist and traveler. He achieved prominence by his studies of Japanese flora (plants), flora and fauna (animals), fauna and the introduction of ...
and
Joseph Gerhard Zuccarini
Joseph Gerhard Zuccarini (10 August 1797 – 18 February 1848) was a German botanist, Professor of Botany at the University of Munich. He worked extensively with Philipp Franz von Siebold, assisting in describing his collections from Japan, but al ...
in 1846 with a new specific name, ''Cephalotaxus drupacea''. Some botanists consider ''
C. koreana'' and ''
C. sinensis'' to be synonymous with ''C. harringtonii''.
Although normally found under the name ''Cephalotaxus harringtonia'', that name violates the grammar rules of Botanical Latin and in 2012 was corrected to ''Cephalotaxus harringtonii''. However, this opinion is still not universally accepted by taxonomists and therefore it is acceptable to use ''Cephalotaxus harringtonia'' until a definitive position has been agreed.
Range and habitat
''Cephalotaxus harringtonii'' is present in Japan. Within Japan, the tree ranges from
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 ...
in the south to
Hokkaidō
is Japan's second largest island and comprises the largest and northernmost prefecture, making up its own region. The Tsugaru Strait separates Hokkaidō from Honshu; the two islands are connected by the undersea railway Seikan Tunnel.
The la ...
in the north. More specifically, it is found in Hondo in the
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 the ...
on Mount Kiyosumi, which is located in the
Awa District within the
Awa Province. It is also found in the
Nagasaki Prefecture
is a Prefectures of Japan, prefecture of Japan located on the island of Kyūshū. Nagasaki Prefecture has a population of 1,314,078 (1 June 2020) and has a geographic area of 4,130 Square kilometre, km2 (1,594 sq mi). Nagasaki Prefecture borders ...
and the
Hiroshima Prefecture
is a Prefectures of Japan, prefecture of Japan located in the Chūgoku region of Honshu. Hiroshima Prefecture has a population of 2,811,410 (1 June 2019) and has a geographic area of 8,479 km² (3,274 sq mi). Hiroshima Prefecture borders Okayama ...
. The variety ''nana'' is found in eastern
Honshū
, historically called , is the largest and most populous island of Japan. It is located south of Hokkaidō across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyūshū across the Kanmon Straits. The island separa ...
as well as
Hokkaidō
is Japan's second largest island and comprises the largest and northernmost prefecture, making up its own region. The Tsugaru Strait separates Hokkaidō from Honshu; the two islands are connected by the undersea railway Seikan Tunnel.
The la ...
, most notably on seaside cliffs and in mountainous areas.
They thrive in partial shade on deep, rich soils.
Cultivation
''Cephalotaxus harringtonii'' has been in cultivation in the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...
since 1829 and is infrequently encountered as a garden specimen. Of the several species that exist in the genus, the Japanese plum yew is the one most often encountered in western gardens.
Several cultivars exist:
*'Fastigiata' was first selected in 1861 in Japan. It grows to 6 metres in height and it characterised by its broad cluster of erect stems and very dark green leaves that spread all around the stem and are strongly decurved. The shoots are unbranched in the upper parts of the plant, while the lower parts have somewhat chaotic projecting side-shoots that hang down and contain leaves in flat ranks. The flowers are also inconspicuous.
Cephalotaxus harringtonia Fastigiata erratic shoot.jpg, 'Fastigiata' plant with a chaotically projecting side-shoot
Cephalotaxus harringtonia 'Fastigiata'.jpg, ''Cephalotaxus harringtonii'' 'Fastigiata'
Pharmaceutics
Omacetaxine
Omacetaxine mepesuccinate (International Nonproprietary Name, INN, trade names Synribo ), formerly named as homoharringtonine or HHT, is a pharmaceutical drug substance that is indicated for treatment of chronic myeloid leukemia (CML).
HHT is a n ...
, a substance derived from the leaves of this plant, is a novel (as of 2008) anti-
leukemia
Leukemia ( also spelled leukaemia and pronounced ) is a group of blood cancers that usually begin in the bone marrow and result in high numbers of abnormal blood cells. These blood cells are not fully developed and are called ''blasts'' or ' ...
drug.
References
{{Taxonbar, from=Q653466
harringtonia
Flora of Japan
Least concern plants