Japanese red maple (Acer palmatum)
Japanese red maple
smooth Japanese maple
SCIENTIFIC SYNONYMS: There are no scientific synonyms for Acer
CONFIRMATION STATUS: Confirmed.
TAXONOMY: The current scientific name for Japanese red maple is Acer
palmatum Thunb. Three subspecies are recognised: 1) Acer palmatum subsp. palmatum. Leaves small, 4–7 cm wide, withfive or seven lobes and double-
serrate margins; seed wings 10–15mm. Lower altitudes throughout central
and southern Japan (not Hokkaido); 2) Acer palmatum subsp. amoenum
(Carrière) H.Hara. Leaves larger, 6–12 cm wide, with seven or nine lobes
and single-serrate margins; seed wings 20–25 mm. Higher altitudes through-
out Japan and SouthKorea; 3) Acer palmatum subsp. matsumurae Koidz.
Leaves larger, 6–12 cmwide, with seven (rarely five or nine) lobes and
double-serrate mar-gins; seed wings 15–25 mm. Higher altitudes through-
There are over one thousand cultivars of Acer palmatum, many of them for
sale as ornamentals throughout the world.
NATIVE STATUS: Introduced, United States and Canada.
GENERAL BOTANICAL DESCRIPTION: Japanese red maple is an
introduced, small, slow growing ornamental tree that may rarely grow to
to 20' tall by 20' wide, but the numerous cultivars are always much smaller.
Its growth habit is variable from upright rounded, horizontal-vased, or
weeping pendulous, depending upon cultivar, and often becoming densely
twiggy with age. The trunk may be single-trunked and branching low,
grafted onto a single-trunked standard, or multi-trunked. The bark is
green when young for green-foliaged types, otherwise brown bark for red-
foliaged types and eventually turning to brown-gray for all types. The
twigs are green, brown, red, or purplish, depending upon cultivar, with
the winter buds almost valvate. The leaves are opposite, with green,
bronzed, red, or purple emergent leaves, depending upon cultivar. Each
of the 5 to 11 (often 7) leaf lobes is narrow, serrated, and acuminate (but
not incised), with the leaf displaying prominent palmate veination. Sinuses
between the lobes are narrow and often extend halfway or more to the top
of the petiole. The fall color may be pale chartreuse, vivid orange, brick red,
or fluorescent flaming red, depending upon cultivar and sun exposure. The
flowers are in clusters of red to purplish inflorescences in late May and
early June are often hidden by the foliage. The fruit is comprised of two
samaras per stalk having incurved wings, in pendulous clusters from the
stems, often becoming red by June and July, and maturing to reddish-
brown in October (often sparsely borne or absisced by this point). It has
a shallow and fibrous root system and will quickly regenerate and spread
upon transplanting, but is subject to drought stress, even in established
REGENERATION PROCESS: Japanese red maple is propagated by
cuttings grafted onto rootstock, rooted stem cuttings, or seeds.
SITE CHARACTERISTICS: Japanese red maple prefers rich, moist, well-
drained, slightly acidic soils, but is moderately adaptable to more adverse
conditions. It is very adaptable to sunlight variations, growing in full sun to
full shade, but usually grows best in partial sun to partial shade.
SUCCESSIONAL DEVELOPMENT: Not applicable.
SEASONAL DEVELOPMENT: Japanese red maple flowers in late May
into early June.
GENERAL DISTRIBUTION: As an introduced ornamental, Japanese
red maple is rarely found growing in the wild and its invasive potential
is considered very limited. As an ornamental, it has been planted through-
out much of the United States.
SKY MEADOWS DISTRIBUTION:
Tree specimens can be found on trails marked in red.
Appalachian Trail/Old Trail
South Ridge/North Ridge
Rolling Meadows/ Lost Mountain
HABITAT TYPES AND PLANT COMMUNITIES: Not applicable.
IMPORTANCE AND USES: Acer palmatum is highly regarded as an
ornamental. It has been called one of the finest exquisite small trees for
texture, form, foliage, and fall color. For centuries Japanese horticulturalists
have developed cultivars from maples found in their country and nearby
Korea and China. They are a popular choice for bonsai enthusiasts. Japa-
nese maple has been grown in temperate areas around the world since the
1800s with the first specimen of the tree reached England in 1820. Today
numerous cultivars are readily available commercially and are a popular
item at garden centres and other retail stores in Europe and North America.
Crooked Run Valley