paper mulberry (Broussonetia papyrifera)
Morus papyrifera L.
Papyrius papyriferus (L.) Kuntz
CONFIRMATION STATUS: Confirmed.
TAXONOMY: The currently accepted scientific name for paper mul-
berry is Broussonetia papyrifera (L.) L'Hér. ex Vent.
NATIVE STATUS: Introduced, United States.
GENERAL BOTANICAL CHARACTERISTICS: Paper mulberry is a
deciduous large shrub or small tree with milky sap that grows to a maxi-
mum height of about 45 ft. (15 m.) and has a mounded appearance as the
older, taller stems are towards the middle of the plant. The twigs of paper
mulberry are hairy reddish brown, the bark is tan and smooth to moderate-
ly furrowed, the wood is soft and brittle, and it has conical buds. Paper mul-
berry has highly variable leaves. The leaves are densely gray-pubescent,
often lobed or mitten-shaped, and are alternate, opposite or whorled along
the stem. The leaf margin is sharply toothed, the leaf base is heart-shaped
to rounded with pointed tips, and the upper leaf surface is rough feeling. In
size they range from 8 to 25 centimeters in length. The smallest leaves are
generally simple with a serrate margin while the larger leaves tend to be
heart or mitten shaped, and the largest leaves are generally deeply lobed,
giving the leaf three large lobes and occasionally two smaller ones near the
leaf base. Its leaf scars are in an alternate pattern although on occasion they
are opposite as well. Separate male and female flowers appear in the spring.
Male flower clusters are elongate, pendulous, 2 ½ to 3 in. (6-8 cm) long,
and composed of many individual flowers. Female flowers are globular and
about 1 in. (2cm) in diameter. The fruits are reddish purple to orange, ¾-1
n. (1.5-2.0 cm) in diameter, and appear in summer. Its fruits are generally
1.5 – 2.0 cm in diameter and are a reddish purple in color, appearing in
Paper mulberry may be confused with the exotic white mulberry and native
trees such as red mulberry, sassafras, basswood, and white poplar.
REGENERATION PROCESS: Paper mulberry spreads both by seed
and through vegetative expansion. The seeds are spread far and wide by
wildlife who feed on the fruits. Paper mulberry expands locally by produc-
ing new plants from its roots.
SITE CHARACTERISTICS: Paper mulberry prefers light and medium
texture soils (sands, sandy loams, loams, and sandy clay loams). It grows in
soils with free drainage as well as seasonally and continually waterlogged
soils. Grows under any rainfall pattern that keeps the soil moist most of the
year. The tree also frequently grows along streams. It can survive a 3–4
month dry period. The tree does best in sunny places; it does not grow well
in heavy shade. It does not tolerate wind well.
SUCCESSIONAL STATUS: Paper mulberry can be found growing
along forest margins, waste areas, and in areas recently disturbed. It is
particularly aggressive in the initial stages of succession, quickly disrupt-
ing the native habitat and becoming a highly invasive species and upsett-
ing the natural ecosystem. While it generally has a hard time establishing
itself in mature forest settings, it can easily become the dominant species
during the early successional stages. The primary limitation on its invasive
capacity is that both male and female trees are necessary for flowering and
seed production. Where only male trees are present, its invasive capicity is
severely limited, although it can still spread vegatively through its strong
SEASONAL DEVELOPMENT: Separate male and female flowers
appear in the spring while the fruits appear in summer.
GENERAL DISTRIBUTION: The tree is native to Japan and Taiwan,
where it is now mostly restricted to cultivation. Paper mulberry was an
ancient introduction eastward across the Pacific to Hawai‘i. It is now recog-
nized as a culturally significant plant in Hawai‘i, which has led to a renewed
interest in its cultivation. On the U.S. mainland, where both fertile male
and female trees have been introduced, it is found from Illinois to Massach-
usetts, south to Florida and west to Texas.
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
The specific distribution of paper mulberry has not been determined.
HABITAT TYPES AND PLANT COMMUNITIES: The flora of its
native habitat is secondary temperate forest. In the Pacific islands, the
flora most often associated with the tree is comprised of introduced plants,
both weeds and cultigens, which vary from island to island. The tree has
virtually disappeared from much of its Pacific island range, but where it
does occur, it is either cultivated or persists in moist valleys where it has
survived after cultivation has ceased. The tree is found mostly in lowland
plantations and homegardens, where it is associated with other cultivated
plants, such as dryland taro and breadfruit.
IMPORTANCE AND USES: The inner bark has been used for cen-
turies in Southeast Asia for paper and textiles. The bark is traditionally
used in Polynesia to make bark cloth known as tapa. The bark is stripped
from the cut stems by making a lengthwise incision across the stem and
pulling it off intact to obtain a single long strip. The inner bark, or bast, is
then separated from the outer bark, and any green matter remaining on
the bast is removed using scrapers; the bast is then washed to remove the
slimy sap. The strips are pounded on a wooden anvil by using a square,
billyclub-like beater made of a hard wood. Two or three of the strips are
then felted together by the pounding, helped by the stickiness of the bark.
Several of the resulting sheets are often pounded together in layers to in-
crease the thickness or to cover over thin spots or holes in the individual
sheets. A bit of paste in the sprinkling water is usually used at this point.
These white tapas are then painted, or as in Hawai‘i, printed with decora-
tive designs. The finest and most delicate tapa in Polynesia was made in
Hawai‘i. Nowadays, however, tapa making in the Pacific is limited to
Tonga and Fiji, and to a lesser extent, Samoa, and the tree and the art are
nearly forgotten everywhere else.
The sweetish fruits are edible, although where only male clones are present,
such as in the Pacific Basin, no fruit is formed. In Indonesia, the steamed
young leaves are eaten.
The plant has other less important uses including medicinal ones. In
Hawai‘i, the slimy sap was used as a laxative and the ash of burnt tapa
was used for treating thrush. In Samoa,an infusion of the crushed leaves
is sometimes taken as a potion for treating stomach pains and ill-defined
abdominal pains. The leaf, bark, and fruit are used medicinally in Indo-
china. The leaves are fed to pigs in Indochina and to silkworms in China.
After removing bark for tapa, the stems can be used for kindling while the
bark fiber can be used to make rough cordage, as can the roots.
The bark cloth is used ceremonially in Tonga, Fiji, and Samoa. In Hawai‘i,
tapa was important in burial wrapping and other funerary customs.
Crooked Run Valley