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Issue No. 0148 - January 23, 2005
by Sue Sweeney
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Ailanthus (Ailanthus altissima), the Tree of Heaven,
Asia, and Brooklyn is often considered by naturalists and
homeowners alike to be a menace to society with little
redeeming value for wildlife. In contrast, the staghorn
sumac (Rhus tyhina) is a great native American, as
useful to humans as to the smaller residents of the
sub/urban environment. The black walnut (Juglans nigra),
another great native American, is cultivated in the wild by
squirrels who adore these tall, graceful hardwoods as much
as humans do. The ailanthus is from the Quassia family of
tropical plants, the staghorn sumac is a cashew family
member, and the black walnut comes from the walnut family
which includes hickories and pecans.
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| Picture: In the Hoyt Street Alley, young ailanthus (Ailanthus
altissima) leaf out in front of the alley’s resident wild
crabapple and shaggy bark hickory. Note the bright red-orange color
of the new leaves; the greenness of the young trunks and the
polka-dot pattern of the lenticels (pores). Stamford CT 2004 The ailanthus, staghorn sumac and black walnut come from totally different
families and backgrounds, but can you tell them apart? All three have
long, palm-like compound leaves but there are difference in flower,
fruit, bark, bud, and leaf shape. This article covers the ailanthus and
the sumac. The black walnut will be the subject of a future article.
AILANTHUS: Graceful, tropical-looking ailanthus is
the tree that grows in Brooklyn, and just about everywhere
else (including Africa and Australia). It’s as much a part
of the urban landscape as the Norway rat, the cockroach, and
the feral cat. Ailanthus was featured in "A Tree Grows in
Brooklyn" where this arboreal immigrant’s determination
to survive and flourish despite all odds gave inspiration to
immigrants of the human species. In Brooklyn, I once saw a
ghostly ailanthus sapling growing out of the dirt floor in a
lightless sub-basement. Ailanthus saplings waving from roof
gutters and fire escapes are common inner-city sights.
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pictures: mature ailanthus at Stamford Cove Island. Summer and fall 2003;
January 2005. |
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As a long-time Brooklyn resident, I have a fondness for my
old neighbor, the "Tree of Heaven", as it is known in its
native China. In China, the mature trees are valued as
ornamentals; and the tree is used for lumber, firewood,
medicine, and silkworm farming. (The wood, by the way, is
similar to ash in look and quality, and actually is quite
useful.) Conversely, in Virginia, where it threatens new
forests, ailanthus is known as “stink-tree”.
Unfortunately, like many back-alley denizens, ailanthus is
“armed and dangerous”. Ailanthus uses its wind- and
water-borne winged seeds (samaras) to spread into
surrounding neighborhoods. Once it gets established, it
spreads into a grove by means of underground shoots.
Ailanthus is a proven allelopath; it uses chemical warfare
to control its turf. The chemicals it makes can ward off at
least 70 other species that could compete with it for space.
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pictures: new ailanthus seeds at Cove Island are very red; the older ones
on Stamford’s 3rd Street have faded to tan –gold. |
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Detail of seeds. |
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| picture: Tropical looking ailanthus “under-planted” with mugwort
Cov e Island Summer 2003 |
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| pictures: ailanthus’ up-swept branches Cove Island, Hoyt Street
Alley and Cove Island, Winter 2004-05; Morgan Street Summer 2004 |
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Ailanthus, however, can not tolerate deep shade, so
despite its chemical armaments, it can’t compete
under the thick forest canopy. Instead, ailanthus
tends to grow in the sub/urban environment where few
trees can compete with ailanthus for ability to
withstand urban pollution. Ailanthus can also
out-compete native trees when the forest canopy has
been disturbed by logging or fire, and it can gain a
foot-hold at the forest’s edge by out-competing and
poisoning other “pioneer” and edge-of-forest plants.
According to the US Forest Service, in China,
ailanthus only grows “in a densely populated area of
China where no wild lands are left.” Chilling
thought.
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| picture: short, stubby curved branches of a mature ailanthus;
the feathery structures are last year’s flower stalks. Hoyt Street
Alley, January 2005. |
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Ailanthus was first imported into North America,
they say, in the 1700's, and was widely planted in
cities (on purpose!) because it was pollution-hardy.
Today, ailanthus is found in this hemisphere, in
Zones 4 to 8, from Argentina to Canada. In the USA,
it’s found everywhere except the really cold places
such as Alaska, Idaho, the Dakotas, and Minnesota.
Ailanthus is still useful for ground stabilization
in pollution-prone industrial sites but I doubt
anyone has to take the time to plant it.
Ailanthus is a fast, fast growing tree that lives
only 25 to 50 years but it can get very large - 60
to 100 feet--in that time. While the individual
trees aren’t’ that long lived for trees, the
ailanthus groves can sustain themselves for hundreds
of years.
Most American wildlife hasn’t much use for the
foreign-born ailanthus. Even white tail deer and
grey squirrels aren’t partial to it. A couple of
bugs of Asian origin munch on it (and presumably are
then munched in turn by birds and small animals).
Honeybees (a European import themselves), though, do
relish the pollen which makes quality honey after
it’s been aged.
Ailanthus is weedy and aggressive; it should be
controlled for the sake of the environment. In
particular, the female plants which send out the
seeds should be kept cut to the ground. Further, the
trees are not desirable around human dwellings.
Larger trees can be a winter/wind hazard and the
water-seeking roots have been known to interfere
with sewer lines and wells. The roots are also said
to give water an unpleasant taste. The males flowers
have a strong order often considered disagreeable
(hence the name “stink-tree”). Ailanthus sap can
cause dermatitis and the tree is a 9 out of 10 on
the bad-for-allergies scale.
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| pictures: vertical striped grey- clay colored bark of a young
ailanthus, detail of same Morgan Street Winter 1004-05 |
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However, there’s good in all of us, and the USA
Forest Service reports that “pharmacological
research is focusing on possible use of ailanthus
extracts for treating cancer, malaria, and HIV-1
infection. STAGHORN SUMAC: Lovely,
graceful, staghorn sumac (no relation to poison
sumac) is valued in North America and Europe as a
beautiful ornamental that also provides for winter
survival food for wildlife. It is an important
source of food for many wild ones including skunks,
songbirds, grouse, deer, and rabbits.
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| pictures: staghorn sumac in the wind at Cove Island (note the
light color to the underside of the leaves); in flower at Scalzi
Park and in the fall at Cove Island. Stamford CT 2003. |
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Humans have also found use for the plant. Staghorn
sumac berries are so high in tannin that they can be
used for tanning. Native Americas made a
lemonade-like drink from them. The European
colonists reportedly used sumacs to make ink. The
branches are easy to hollow out and useful as
temporary pipes, kids’ toys, handicrafts, and the
like.
Staghorn sumac’s natural range is eastern North
America, from southern Canada to Georgia. It is
hardy in Zones 4 to 8, just like ailanthus. Also
like ailanthus, staghorn sumac is a “pioneer” and an
edge-of-forest plant. Staghorn sumac seeds are
carried between locations by the wild critters which
eat its seeds, rather than by wind like the
ailanthus. But like ailanthus, once established,
staghorn sumac spreads into a grove by means of root
suckers. Staghorn sumac likes rocky, sunny, dry hill
sides and banks with a neutral or high PH
(limestone) content. Ailanthus isn’t particular
about soil conditions, so it does both wet and dry,
acid and limey. However, staghorn sumac can probably
survive in soil that is more alkaline than ailanthus
can tolerate and, conversely, ailanthus’s range
extends farther into acidy soils and wet soils than
the staghorn sumac can tolerate.
Staghorn sumac, like ailanthus, is a sun-seeker
that can’t tolerate dense shade. While ailanthus
does in the competition with chemical warfare, sumac
uses shade. Staghorn sumac groves create such dense
shade that few other plants can survive underneath
it. Ailanthus groves are also dense and shady. Both
ailanthus and sumac groves are too shady for their
own young to survive.
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| picture: staghorn sumac fruit; note the downy leaf and flower
stalks |
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| picture: trunks of young ailanthus mixed with young staghorn
sumac on Bedford Street in Stamford CT January 2005. The sumac are a
dusty red-purple; the ailanthus are greenish, gray, and
orange-brown. |
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IDENTIFICATION: Staghorn sumac and ailanthus
not only have several similar physical
characteristics, they tend to grow in similar
places. It’s very important to be able to tell the
trash (ailanthus) from the treasure (staghorn sumac)
when deciding which plants to destroy. While
ailanthus and staghorn sumac have many similarities,
if you look closely there are also differences.
Height: Staghorn sumac seldom grows higher
than 15 feet in the north and 35 feet in the south;
so you can count on the tall ones (up to 80 feet),
being ailanthus.
Form: Both ailanthus and staghorn sumac
have slender, straight trunks, and upward curving
branches with blunt ends. The staghorn sumac’s
branches and leaf stalks have a velvet coating like
deer antlers in winter, hence the name. Ailanthus
branches come in whorled tiers; the staghorn sumac
has a few stout branches, unusually arising at a “Y”
angle from a single crotch. Mature ailanthus have
rounded crowns; staghorn sumac’s are more
flat-topped. |
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| pictures: to the left is the lenticel pattern of a young
staghorn sumac; center shows the sumac’s bud and dusty reddish bark;
on the right is a young ailanthus – note the light colored lenticels
and the smile-shaped leaf scars. |
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Bark- saplings: The young trunks on both
plants have smooth bark dotted with lenticels
(pores); the lenticels of the ailanthus are light
colored and so pronounced as to give the trunk a
polka-dot appearance. The sumac’s lenticels match
the bark color. The young ailanthus bark is a
grayish clay color or a bit orangey. The young
staghorn sumac’s bark has a whitish bloom over a
light colored, thin, smooth bark with purple
undertones. Bark- mature plants: the bark
on “teenage” ailanthus has a diamond pattern
sometimes compared to a cantaloupe’s skin; older
Ailanthus become craggier and has a vertical
pattern. The staghorn sumac’s bark develops
horizontal streaks with age and darkens but remains
smooth, and is sometimes scaly or peeling.
Leaves: Ailanthus and staghorn sumac have
alternate, compound leaves that are 1 to 3 feet long
with 9 to 29 leaflets. The 3” to 5” leaflets are odd
in number – arranged in opposing pairs along the
leaf stalk with a single terminal leaf. The
ailanthus, though, has smooth-edged leaves, often
with a single lobe at the bottom; staghorn sumac
leaves are toothed.
Fall color: Ailanthus turns yellow and tan
in the fall; staghorn sumac turns red, ranging into
purples and oranges.
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| picture: left is a staghorn sumac; center and right are
ailanthus twigs in winter. Note the sumac’s new buds are in the
center of the scar from last years, leaf; the ailanthus buds are at
the top of the old leaf scar. |
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Flowers and fruit: The two plants have
completely different fruit. Both have greenish
flowers at the branch tips. The ailanthus’ come in
whitish-green foamy plumes. As mentioned the male
flowers stink. The staghorn sumac’s flowers come in
tight lime green pyramids. Ailanthus flowers mature,
on the female plants only, into gold clusters of
winged seeds tinged with rust (aging to light tan);
staghorn sumac has fuzzy berries that go from lime
to deep red.
Leave scars and buds: Believe it or not,
comparing the leaf scars and buds points out the
most interesting difference between these two trees
and a few others. Ailanthus leaf scars are smile- or
shield-shaped with the new bud at the top of the
scar; staghorn sumac leaf scars are closer to
heart-shaped and, amazingly, the new bud is right in
the center of the old scar! The sumac buds are
usually hairy if you look closely enough.
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| pictures: left is the terminal leaf of a staghorn sumac; to the
right is the same for an ailanthus. Note that the sumac has a
toothed leaflets, but the ailanthus’ has only lobes at the bottom of
the leaflets. |
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| pictures: left and center staghorn sumac; right is ailanthus. |
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picture: detail of
emerging ailanthus foliage spring 2004.
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