Thursday, April 24, 2014

Wildflowers of 2014 - #8 Red Maple (Acer rubrum) and #9 Speckled Alder (Alnus rugosa)

On Tuesday April 22nd I photographed my eighth and ninth wildflowers of 2014.  Both of these blooms were on native trees.  Like the other trees that I have photographed in bloom, both of these trees have flowers that bloom before their leaves emerge.

Wildflowers of 2014 - #8 Red Maple (Acer rubrum)

Depending on the weather, individual Red Maple trees in Michigan may bloom any time between March and May. I found several Red Maples in bloom.  Red Maple trees may be either male, or female, or both.  All of the trees that I photographed appeared to have male flowers.  These trees release large amounts of pollen, relying on the wind to carry the pollen to female flowers.  Wind-pollinated trees like Red Maple are responsible for the stuffy heads and watery eyes that many people (including my wife) are suffering through right now.

Red Maple (Acer rubrum) in bloom

Male flowers of Red Maple - note the pollen covered anthers

A sprawling Red Maple tree

Male flowers on a Red Maple

A closer view of the male flowers
Wildflowers of 2014 - #9 Speckled Alder (Alnus rugosa)

My second new wildflower of the day and ninth wildflower of the year was this one.

The flowers of this small wind-pollinated tree are 1-2 inch long catkins.  Male and female catkins are separately located on the tips of branches.  Male flowers are larger than female flowers.  In the pictures above and below you can see both the dangling male catkins and the shorter erect female catkins.  After pollination, the female catkins will become woody and resemble small pine cones.

Male (dangling) and female (erect) catkins of Speckled Alder
I was fairly certain that this tree was a Speckled Alder (Alnus rugosa or A. incana) based on the catkins and reddish bark.  The bark is covered with white horizontal lenticels (pores) which allow air to enter the trunk and branches.

Speckled Alder (Alnus rugosa) - note the dark red bark and white lenticels

Speckled Alder, also known as Gray Alder or Tag Alder, often grows in dense stands along streams and in other wet places.This small stand was growing along the edge of a cedar swamp.

A small stand of Speckled Alder

Sometimes when trying to identify a tree or shrub, it can be helpful to clip a twig for closer examination later.  Later when I looked at one of my tree books (Michigan Trees by Barnes and Wagner), I noted that the twigs of this tree have a triangle-shaped pith.  When I cut into the twig, this triangular pith confirmed my Speckled Alder identification. 

Cross-section of a Speckled Alder twig - note the triangular pith

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