Sugar Maple

Acer saccharum Marshall – Sapindaceae – soapberry family

Sugar maple is the tree that yields the best maple syrup and is the major ‘hard maple’ of commerce.  It is a very common street tree in Albion.

Most maple leaves have three major lobes and minor lobes that come off of these.  In red maple, the junction between the major lobes is often at a sharp angle, i.e. forming a ‘V.’  In sugar and Norway maples the junction is not at a sharp and forms a ‘U.’ It’s relatively easy to distinguish a sugar maple from a Norway maple using bark characters.  Sugar maple has an irregularly plated bark while Norway maple has a regularly grooved bark.  In addition, in spring or summer when you break a leaf stalk or twig, a sugar maple generally has clear sap while a Norway maple has milky sap.

Our street maples, including the box elder, have distinctive winged fruits that often break into one-seeded segments.  There are typically two one-seeded segments per fruit, although the rarely-planted Amur maple may have three.  When they break into segments, each segment has a wing and the fruits ‘helicopter’ downward, when they may be caught by the wind.  If they don’t break apart or get caught by the wind, they fall to the base of the tree. Quite a few introductory biology students have climbed to the band director’s scaffold on a windy day at the A-field to experiment by dropping fruits either still hooked together, as winged, one-seeded segments, or as one-seeded segments from which the wings were removed as an experimental treatment.  Guess which dropped items travel farthest?  Are the wings advantageous to the tree for wind dispersal?  Who knows?  Many paired fruits of silver maples and sugar maples that don’t ‘helicopter’ are seen each spring floating in vernal pools and down streams in our area.  Perhaps the wings are for water dispersal in some species.  In the box elder, they just seem to be paired dry things that hold on to the trees all winter long.  Botanists call the fruits of our native maples ‘a schizocarp of 2 samaras.’  A schizocarp is a general term for a fruit that splits into smaller (usually one-seeded) segments.  Samara is the general term for a winged fruit.

In the Albion area, sugar maple is the last of the common maples to flower.  This generally occurs in late April and early May.  In the crazy, early spring of 2012, sugar maple reached its peak flowering at the end of March.