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The Monday Garden
Shades of Maple: The Flowers

Issue No. 163 - May 8, 2005
by Sue Sweeney

Yes, Virginia, trees flower. While tree flowers are a source of much of the misery of spring allergies, the flowers, together with the buds, can be the most beautiful parts of the tree. The maple clan has some of the most beautiful and distinctive flowers in “treedom”.

Spring bloom order: First, while there’s still snow in the shadows, the pom-poms of silver maples appear to feed our precious early-waking pollinators. The silvers are closely followed by their close cousins, the red maples. Then, 2 or 3 weeks later, mid spring is announced by the breathtakingly beautiful but horribly destructive invasive lime green Norway maples; their colors perfectly accenting all of the other spring flowers. After that, in late April – early May the elegant, lordly sugar maples, the box elders (the curious ash-like, compound-leaf maple), and the attractive but invasive sycamore maples bloom at about the same time.

Picture: Norway maple flowers beginning to close as they age, Strawberry Hill, Stamford CT April 2005
Each of the maples has a distinct flower, except, of course, the reds and the silvers which I suspect interbreed for the sole reason of driving botanists crazy.
  Silver Maples (Acer saccharinum): I find it puzzling that maples with such remarkably different leaves and seeds, and, occasionally very different bark, can be so hard to distinguish when it comes to buds and flowers. The silvers that I know have flower clusters similar to reds, but duller, darker, and not as showy. If the tree doesn’t have the silver’s distinct bark or a give off bad odor from a broken twig, it still might be a silver (or a mostly-silver crossbred-mutt). Since reds and sliver bloom while it’s still much too cold to leaf out, sometimes you can only guess whether it is a red or a silver at the time of bloom. (Look around the tee, you could get lucky and find some of last year’s leaves.) Silvers bloom reliably every year.

Pictures: Silver maple flower inspection is also complicated by the height of the trees’ lowest branches; a tall ladder would be a good identification aid. First picture: Strawberry Hill; second two: Scalzi Park. Both of these trees produce characteristic silver maple seeds and leaves but both have red maple-looking bark. All Stamford CT March 2005

Red Maples (Acer rubrum): The red maple blooms every year, and every other year tends to be an even more spectacular. The reds’ flower clusters, from a distance, look like fuzzy red balls or pom-poms, starting out very red and turning more yellow and than orangey before dying. The flowers are showy and are easy to spot from a distance. One clue to the red or silver mystery is that the reds generally start bearing seeds at a much younger age than the silvers. Reds can start when they are around 4 years old but silvers need to be 11 years or so. So a very young maple tree with the fuzzy pom-poms is more likely to a red.

Pictures: A red maple against the sky in the front yard of an apartment complex on Hoyt Street, Stamford CT (2004); up close at the First Presbyterian, Stamford CT April 2005

Norway Maples (Acer plantanoides): The Norways produce showy corsage-like “bouquets” of small lime green flower-looking flowers; some cultivars can have red or maroon sepals around the flowers. Astoundingly, the US Forest Service, in a May 2005 update of its entry on the ubiquitous Norway maples in the FEIS data base noted: “The biology and ecology of Norway maple are not well-studied in North America. More research is needed to better understand its key biological traits, habitat requirements and limitations, and interactions with native North American flora and fauna.”

Pictures: Norway maple flowers, respectively at Scalzi Park and Strawberry Hill, Stamford CT April 2005

Sugar Maples (Acer saccharum): The sugars, the lofty, long-lived nobles of the maple world, have tiny, light olive green flowers on long, thin, flexible stems. The tree, from a distance appears to be fringed, so at this stage looks much like the red oaks which have light green flowers in hanging tassels and vertically striped, light colored trunks. The red oaks, though, will have tiny oak leaves at the top the flowers and the flowers are little balls along the sides the fringy stems.

Sugar maples are said to not start producing seeds until they are 30 to 40 years old, and then don’t necessarily produce flowers (and seeds) every year. Each maple seems to get to decide for itself how often it wishes to flower. Some do it every year; but for other the interval can up to seven years. The Norways, in contrast, make millions of seeds every year, which is one of the reasons why they effectively out-compete the native maples (and almost everything else in sight).


Pictures: The first picture, of one of the lovely sugar maples at the First Presbyterian Church, Stamford CT, was taken in 2003; this tree hasn’t had more than a flower or two since then. The second two pictures are of one of the young sugar maples in a vest pocket park on Strawberry Hill Ave., Stamford CT. This tree blooms every year but its neighbor, probably purchased by the Parks Department as part of the same nursery lot, hasn’t bloomed for some time. The non-flowering tree puts its energy into making energy—it leafs out significantly faster than its flowering sibling. April 2005

Box Elders Maples (Acer negundo): The short-lived, sometimes “weedy” box elders flower reliably every year, starting fairly young, but flowers don’t always turn into seeds. Like the sugars, the trees look fringed when flowering. The flowers come out late enough so that by the time they get really fringy, the compound leaves are half out as well. (With the sugars, the leaves usually follow the flowers.) While the flowers are fringy like the sugars, the details of the flower structure are very different (see the pictures). In addition, the box elders have a smooth-ish or scaly bark and trade-mark bright olive-green twigs. The sugars in contrast have graceful vertical fissures in their bark, revealing a reddish or orangey under-bark, and the sugar twigs are brown or mahogany.

Pictures: Box elder beginning to flower Spring 2004, Cove Island; box elder in full flower April 2005 Grayrock Street, Stamford CT

Sycamore maples (Acer pseudoplatanus): This alien, invasive maple, which is popping up all over town, has a grape-like hanging clusters of lime-green flowers which appear with leaves. You can often see the stems left over from last year’s seeds.

Pictures: Sycamore maple in full flower April 2005 Forest Street, Stamford CT May 2005

From The Monday Garden. Copyright © by Sue Sweeney. Reproduced with permission. 

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