The Cherries: genus Prunus
The genus
Prunus is a large one, and includes a
number of trees you will not satisfactorily identify. In this
genus are cherries, plums, almonds and peaches. There are a few
peach trees around the area, but most of what you will see are
cherries. There are any number of cultivated cherries about,
most beyond the scope of any tree book you will purchase.
Prunus flowers are showy, with five petals
and sepals, many stamens, and a five part pistil. The fruits are
drupes (flesh fruits with a hard stone, containg one seed), colored from red to black. The twigs, branches, and
trunk usually have long horizontal
lenticels. At least when
young, the bark is dark and silky, much like a young birch's.
The leaves are alternate and toothed.
Scientific Name:
Prunus pensylvaniana “Pennsylvanian
plum-tree”
Common Name: Pin Cherry
Family: Rosaceae (roe-ZAY-see-ee)
Bark: Silky, red-brown, with many horizontal lenticels.
Buds:
Distinctive Characteristics:
Distribution: Here and there in the region.
Flowers:
Fruit:
Habit: Small tree.
Habitat: Young woods: this is an early-stage tree in the succession after fires, for instance.
Leaves:
Similar trees
Twigs:
Scientific Name: Prunus serotina
(PRUE·nus seh·ROTTen·uh)“late plum-tree”
Common Name: Black Cherry, Rum Cherry
Family: Rosaceae (roe·ZAY·see·ee)
Bark: Dark, almost black, scaly, with orangy patches
beneath. Young bark dark red brown, glossy, with long horizontal lenticels.
Buds:
Distinctive Characteristics: Twigs, flower, fruit,
leaves.
Distribution: Common native tree.
Flowers: White, somewhat ill-smelling, in cylindrical
racemes, 10 cm long. Flowers small, 8 mm across, with 5 petals.
Fruit: When ripe, black. A thin-fleshed drupe, about
1 cm in diameter. Astringent. A great favorite of birds.
Habit: Does not spread much, branches somewhat pendent.
Can be a good-sized tree, but the valuable wood means old black cherries are
rare.
Usually mauled by tent caterpillars in the spring. At any time of the year their webs are typical.
Habitat: Dry, sunny woods. Because
birds eat the fruit greedily, it spreads rapidly to waste places, along fences, &c.
Leaves: Alternate, finely serrate,
leathery, dark green, with acuminate point, acute base, 3 to 6 inches long,
short petiole. Leaves are distinctive, with practice.
Similar trees Without leaves, resembles a black
birch.
Young trees have bark like other cherries, and like the young birches.
Twigs:
Slender, dark, with odor and taste of the center of a cherry
chocolate candy. Chewing the twigs is the best way to identify
this tree. What you taste is a precursor of cyanide, and the
wilted foliage has poisoned livestock. Moral: chew with
restraint, and spit freely.
Scientific Name:
Pseudotsuga
(PSEUdo·TSOO·gah) “false hemlock”
Common Name: Douglas fir
Family: Pinaceae
(pin·AY·see·ee) the Pine family
Bark:
Buds:
Cones:7 cm long, papery, with extremely
distinctive three-pointed bracts protruding beyond the scales.
Distinctive Characteristics:
Distribution: Native to western United
States.
Flowers:
Habit: Large conifer, rather spruce-like
from distance.
Habitat: In cultivation.
Leaves:
Similar trees
Twigs:
Scientific Name:
Ptelea trifoliata
(TEE·lee·uh
try·foe·lee·ATE·uh)“three-leaved Ptelea”
Common Name: Hop Tree
Family: Rutaceae (rue·TAY·see·ee): the orange/citrus family
Bark:
Buds: Visible only as pale tan downy spot
(1 mm by 2 mm high) in top of leaf scar, itself only 3 mm high.
Distinctive Characteristics: Flowers, leaves, fruits.
Distribution: All of eastern Massachusetts
Flowers: May. In convex corymb, yellow green, fragrant.
Fruit: June. Samara,
roughly circular, 2-2.5 cm. in diameter, with single seed in center. Slightly
cordate base, tip cuspidate.
Habit: A small, usually leaning tree, rarely 20 feet tall.
Habitat: Waste places.
Leaves: Alternate, compound
with three leaflets. Yellow in autumn.
Similar trees
Poison Ivy (a
liana or
small single stemmed bush) has similar leaves.
Elm fruits are similar.
Twigs: Slender, dark,
warm brown.
Pyrus includes a number of differing plants. The cultivated
apple,
Pyrus malus, is commonly seen in fields and lawns that
were once orchards. The Bradford Callery Pear,
Pyrus calleryana
var.
Bradford is a small and very commonly planted street tree.
Crab apples of all types are widely cultivated. The mountain ashes prefer
higher altitudes than those of eastern Massachusetts, although a cultivated
mountain ash, the rowan,
Sorbus aucuparia, will be seen on the
occasional lawn.
As members of the Rosaceae, Pyrus trees will have the typical
five petaled, five sepaled showy flower of the family, and a fleshy fruit,
called a pome. The fruits of most resemble large blueberries in size, more
than they do apples. Mountain ashes have pinnately compound leaves, the rest
of the genus has toothed, simple leaves. All leaves all alternate. The
genus has persistent stipules.
Scientific Name: Pyrus malus (PIE-rus
MAY-luss)
“Pear”, “Apple.” Sometimes assigned to the genus Malus (MAY·luss), as M. pumila.
Common Name: Apple.
Family: Rosaceae.
Bark: Thinnish, somewhat scaly. Smooth and greenish on young growth.
Buds:
Distinctive Characteristics: Fruit.
Distribution: Old World tree, present all over the area.
Flowers: Perfect, 5 white petals, many stamens, 5 green
sepals, 4 cm across. Fragrant and showy.
Fruit: A pome, green to red, 8-12 cm in diameter, usually
insect-infested, like a small, crummy apple, which is exactly what it is, in
fact. (Most apples in this area are Macintoshes, by the way.)
Habit: A small, solid tree, with trunk (often over 15”
in diameter) dividing low, with spreading branches, often bearing
watersprouts.
Habitat: Present in and about old orchards. Common on
lawns in the suburbs, where houses have been built on land that was once
orchard. The apples planted all about parks are always Crabapples. P.
malus is not, to my knowledge, planted, except commercially for its
fruit.
Leaves: Alternate, serrate, wooly beneath, medium green.
Veins curve along parallel to the leaf margin. Pointed at end, blunter at
base, 8-15 cm long.
Similar trees Crabapples resemble the Apple, but are
planted for decorative purposes. I would debate whether they can possibly be considered
decorative, given that they are small, undistinguished trees without autumn color or
graceful shape, and the fruit are unappetizing and usually brownish. Crabs have smaller, more delicate, less
hairy leaves. Real apples are always escapes or remnants from orchards.
Pears (Pyrus communis) have blockier bark, spiny buds, and
smaller, glossier leaves. Pears are also more upright.
Twigs: Leaves and fruit borne on spur shoots.
Scientific Name: Pyrus calleryana var.
Bradford (PIE·russ cal·ler·YAY·nuh)
Common Name: Bradford Callery Pear
Family: Rosaceae.
Bark: All over the trunk and twigs.
Buds: Hoary, like yo' mama.
Distinctive Characteristics:
Distribution: Introduced. Very popular with
landscapers. The city of Cambridge seems fond of them (Mass. Ave. southeast
of Porter Sq., for instance.)
Flowers: White, in flat-topped racemes to 10 cm.
across. April.
Fruit: A black, spherical pome, in no way resembling the
pear you eat, except for the“stony” texture when bitten into. About 15 mm.
in diameter.
Habit: Ascending branches. Because it became trendy in
recent years only, the Bradford Callery Pear is usually seen as a young,
hence small, tree.
Habitat: Very commonly planted street tree, in some
areas.
Leaves: Simple, serrate, alternate. Glaucous above and
below, 10 cm. long, 8 cm. wide, with obtuse base and acute tip.
Similar trees Although there is nothing very distinctive
about the tree, no other trees much resemble it either. Cherries, apples and
eating pears (Pyrus communis) have different bark, the other
types of Pyrus (the mountain ash group, sometimes
classed in the genus Sorbus), have pinnate leaves.
Twigs:
