Black-gum

Leaves

Form

• Deciduous, alternate, simple
• Shape variable
• In clusters on dwarf branches and at the end of major shoots
• Sparsely hairy on the veins

Length

• 5–12 cm

Width

• Usually widest above the middle

Colour

• Upper surface shiny dark green
• Lower surface whitened
• Petiole reddish

Margin

• Smooth, wavy

Buds

Form

• Terminal bud present, curved, pointed
• 5 scales, hairy at tips
• Lateral buds smaller
• Diverging widely from the twig
• Leaf scars broadly crescent-shaped, with 3 sunken vein scars

Length

• Terminal buds 7 mm

Colour

• Yellowish-brown to dark reddish-brown
• Vein scars whitish

Twigs

Form

• Moderately slender
• Pith with hard crossbars
• Dwarf branches present

Colour

• Reddish-brown with a greyish skin
• Crossbar greenish

Flowers

Form

• Small, inconspicuous, on long hairy stalks
• In small clusters, racemes or solitary
• In the leaf axils, especially on dwarf branches

Colour

• Greenish-white

Structure

• Polygamo-dioecious

Floral timing

• Late spring, after leaves reach their full size

Fruits

Form

• Solitary or in clusters at the ends of long stalks
• Plum-like
• Flesh thin, oily, sour
• Stone indistinctly ribbed

Length

• 1–3 cm

Colour

• Blue-black

Structure

• Drupe

Bark

Form

• Flaky when young
• Developing thick, irregular ridges broken into block-like segments

Colour

• Grey when young, becoming dark grey

Wood

Texture

• Moderately heavy, hard, strong
• Resistant to abrasion

Colour

• Brownish-grey

Morphology

• Diffuse-porous, close-grained

Size

Height

• To 20 m
• Larger in the southern part of its range

Tree form

Forest-grown

Trunk

• Central stem distinct into the upper part of the crown

Crown

• Broad, flat-topped, with crooked, horizontal branches

Habitat

Site

• An understory tree on low, wet ground
• Along streams or in swamps

Light tolerance

• Moderately shade-tolerant

Range

In Ontario, north of Lake Erie

Other

Small trees. Black-gum is the only species of Nyssa native to Canada.
A variety exists that has grey twigs and thin, almost translucent leaves with many clear dots on the lower surface.