Saturday, June 9, 2012

Little White Flowers

The bright colors of newly opened flowers carpet the road ditches, and this makes riding my bike a little more dangerous. I am risking skinned elbows and broken bones as I crane my neck to attempt ride-by plant identification, or swerve onto the soft shoulder to get a better look.  It is worth it to greet old friends.

Sometimes in February when the ski tracks on the Birkie Trails are just perfect, I wish it could always be ski season. Then spring arrives in all its glory. In any season, I love seeing a delicate white dusting in the ditches and forests. Of course, right now the white dusting is flower petals instead of snowflakes.

Three species with white flowers stand out in my mind this week. Starflower is one. They are aptly named, since their white petals reflect light so brightly that they seem to glow from within, and overexpose any photo I take of them. This low plant has a whorl of lanceolate (long, narrow, but wider in the middle) leaves with many delicate veins. Up to three flowers seem to float above the whorl on slender pedicels. What makes this flower truly unusual is the number of petals. Sets of seven are very rare in nature!

Often growing nearby in the sun-dappled edges of northern woods are Canada Mayflowers, sometimes called False Lily of the Valley. A shady patch of their small oval leaves may bear no flowers at all. Sometimes just a few plants in a patch will grow a taller stem with two or three leaves and a spike of snowflake-like white flowers. The single leaves may help provide a “chosen plant” with the added energy it needs to bloom and set seed. Since the plants in a patch are clones connected by underground stems, all the little sugar factories can work together. As all hardy northern residents know, teamwork is necessary in the face of poor soil and short summers!

The third white flower that caught my eye has a couple tricks up its leaves, or rather, in the flowers themselves. Bunchberry is the smallest plant in the Dogwood family. With radiant white flowers in the summer and brilliant red bunches of berries in the fall, this common plant is always a treat to see. And it is more than meets the eye! The four white things masquerading as petals are actually sepals. We usually find sepals as the small green leaves cupping a flower. While the sepals of bunchberry flowers are unusually showy, the petals are unusually dinky.

Small though they may be, the cluster of tiny flowers bears petals designed like a catapult. When the flowers are ready, the lightest touch of a potential pollinator’s foot will trigger the petals to burst open in less than a millisecond.  This triggers the stamens to shoot up and fling pollen grains with the force of a huge explosive.

According to J. Edwards, et al, the authors of the original study published in the journal Nature:
“Bunchberry stamens are designed like miniature medieval trebuchets — specialized catapults that maximize throwing distance by having the payload (pollen in the anther) attached to the throwing arm (filament) by a hinge or flexible strap (thin vascular strand connecting the anther to the filament tip). This floral trebuchet enables stamens to propel pollen upwards faster than would a simple catapult. After the petals open, the bent filaments unfold, releasing elastic energy. The tip of the filament follows an arc, but the rotation of the anther about the filament tip allows it to accelerate pollen upwards to its maximum vertical speed, and the pollen is released only as it starts to accelerate horizontally.”

The pollen experiences 800 times the acceleration that the Space Shuttle does during liftoff, and is launched more than ten times the height of the flower.  From this lofty height of 2.5 cm, they can be more easily carried by the wind. Or the soaring pollen might smack into a bee and travel to a different flower that way. Bunchberries cannot self-pollinate, so this cross-pollination is necessary.

Flowers like these are worth a little swerving as I ride down the road. Those who are risk averse may choose to walk instead. In either case, drivers should be alert and give a wide berth to the many bikers and walkers out enjoying the wildflower gallery along our roadsides.

For over 44 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 13470 County Highway M. The new exhibit, STAR POWER: Energy from the Sun, opened in May 2012 and will remain open until April, 2013. Find us on the web at to learn more about our exhibits and programs. Also discover us on Facebook, or at our blogspot,

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