Ironwood

Silhouette - ironwood
  • Latin name: Ostrya virginiana (Mill.) K. Koch
  • French name: Ostryer de Virginie
  • Synonym(s): Hop-hornbeam
  • Taxonomic Serial Number: 19511
Description

Leaves

  • Leaf with detail of indistinctly double-toothed margin - ironwood

Form

  • Deciduous, alternate, simple
  • Arranged in 2 rows along the twigs, successively larger toward the tip of the shoot
  • Elliptic, tapering from the middle to a long sharp tip
  • Usually widest near the middle
  • Base narrowly rounded or indented
  • Lower surface hairy
  • Texture soft
  • Veins straight, parallel

Length

  • 7–12 cm

Colour

  • Upper and lower surface dark yellowish-green

Autumn colour

  • Dull yellow

Margin

  • Each vein ends in a sharp tooth, with somewhat smaller intervening teeth
  • A branch vein may also end in a tooth

Buds

  • Lateral bud and leaf scar - ironwood

Form

  • Ovoid, pointed
  • Spreading from the twig, slightly hairy
  • Several scales, striated, not in regular rows
  • No true terminal bud
  • Leaf scars with 3 vein scars

Length

  • 3–4 mm

Colour

  • Greenish-brown

Twigs

  • Winter twig - ironwood

Form

  • Slender, not as wide as the buds

Colour

  • Dark reddish-brown

Flowers

  • Pollen catkins and end bud in winter condition - ironwood

Form

  • Pollen flowers in drooping catkins, in groups of 2 or 3 at the tip of twigs
  • Visible but short, stiff, erect in winter
  • Seed flowers in elongated clusters (racemes) at the tip of new leafy shoots
  • Pollination takes place as the leaves begin to appear

Length

  • Pollen flowers 15–50 mm

Structure

  • Monoecious

Fruits

  • Fruit sac (left); nut (right) - ironwood

Form

  • Small flattened nut enclosed in an inflated sac covered with stiff hairs
  • In clusters at the tip of a short drooping axis
  • Sacs fall during winter, leaving the axis attached to the end of the twig

Length

  • Nut 5–8 mm
  • Sac about 15 mm

Bark

Form

  • Short, narrow, longitudinal strips, loose at both ends
  • Easily rubbed off

Colour

  • Greyish-brown

Wood

Texture

  • Heavy, very hard, tough

Colour

  • Light brown

Morphology

  • The densest Canadian wood; close-grained
  • Diffuse-porous; pores barely visible to the naked eye
  • Rays and annual rings indistinct

Uses

  • Tool handles

Size

Height

  • To 12 m

Diameter

  • To 25 cm

Tree form

  • Silhouette - ironwood

Forest-grown

Trunk

  • Upright, distinct almost to the top of the tree

Crown

  • Wide-spreading, with long slender branches

Habitat

Site

  • Well-drained slopes and ridges

Light tolerance

  • Very shade-tolerant

Associated species

  • An understory tree in broadleaf forests
Photos
  • Ironwood
  • Ironwood
  • Ironwood
  • Ironwood
  • Ironwood
  • Ironwood
  • Ironwood
  • Ironwood
  • Ironwood
Distribution map
Distribution map - ironwood
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