Artificial Group Floriferae Polypetalae  Subclass Rosidae

Aceraceae (Maple Family)
     [Latin = "sharp"]

     2 Genera (1 on campus)
     112 species

I. Leaves

     A. Opposite
     B. Simple
     C. Most estipulate
     D. Palmate lobing & venation or
          Pinnately compound

II. Flowers

     A. Regular
     B. Perfect or imperfect (dioecious)
     C. 4-12 stamens
     D. 2 lobed, 2 celled pistil with wings along back

III. Fruit

     A. Double samara


IV. Economic Importance

     A. Lumber differs in size & variation of rays
          hardness & strength

          1. Hard maples (Acer saccharum, A. nigrum)
               Furniture, veneers, musical instruments,
               bowling alleys, dance & gym floors, sporting goods
               railroad ties if pressure treated with fungicide

          2. Soft maples (A. rubrum, A. saccharinum)
               Millwork, shuttles, spools, bobbins

     B. Methanol distillation

     C. Maple sugar & syrup

     D. Ornamental

V. Range

     A. Throughout N. hemisphere, especially in E. Himalayans
          & central China


Species comparison

Leaves with 5 lobes

I.  Acer platanoides (Norway Maple)
     [like Platanus]

     A. Glabrous
     B. Sinuses 1/3 length of leaf
     C. Long petiole with milky latex

II. A. saccharinum (Silver Maple)
     [Latin "sugary"]

     A. Silver/white underside
     B. Sinuses 2/3 length of leaf
     C. Silver gray bark when young, 
          long, thin, scaly plates unattached at ends
          when older

III. A. pseudoplatanus (Sycamore Maple)
     [Latin "false Platanus"]

     A. Glabrous, light green, glaucous
     B. Sinuses 1/2 length of leaf
     C. Broad, green buds



Leaves with 3 or 5 lobes

I. A. campestre (Hedge Maple)

     A. Pubescent
     B. Rounded lobes, teeth, sinuses
     C. Milky latex
     D. 5-10 cm wide

II. A. nigrum (Black Maple)
     [Latin = "Black"]

     A. Pubescent
     B. Dark green, drooping leaves
     C. Persistant stipules
     D. 10-15 cm wide

III. A. saccharum (Sugar Maple)
     [Latin = "sugary"]  

     A. Glabrous
     B. Green, non-drooping leaves
     C. Nonpersistant stipules
     D. 10-15 cm wide

IV. A. rubrum (Red Maple)
     [Latin = "red"]

     A. Somewhat glaucous
     B. Young leaves, bud scales, fruit red
     C. Sharp acute sinuses
     D. 5-10 cm wide



Leaves with 3 lobes

I. A. ginnala (Amur Maple)

     A. Lateral lobes at right angles to midrib
     B. Sinuses 1/2 length of leaf
     C. Red buds

Leaves with 5-9 lobes

I. A. palmatum (Japanese Maple)

     A. Sinuses >2/3 length of leaf
     B. Serrated margin
     C. Green/reddish

Leaves pinnately compound

I. A. griseum (Paperbark Maple)

     A. Trifoliate leaves
     B. Pubescent
     C. Papery bark

II. A. negundo (Box Elder)
     [Malayan name for tree with this leaf type]

     A. 3,5,7 leaflets
     B. Glabrous
     C. Green stem