A Close-up View of the Wildflower
"Scarlet Pimpernel"

(Anagallis arvensis)


by Brian Johnston   (Canada)



In the world of wildflowers, scarlet pimpernel must be considered a diminutive, but beautiful amusement.  In fact, the genus name Anagallis is derived from the Greek for "amusing".  The long-stalked, nodding flowers are salmon to scarlet in colour, and usually about 1/4 inch (6 mm) in diameter.  These flowers open only in full sunlight, and close as cloudy weather approaches.  This habit has led to the plant being called the "poor man's weatherglass".  Scarlet pimpernel is a member of the primrose family (Primulaceae).
 
The image above shows a typical flower with its five petals, and an equal number of sharply pointed green sepals.  The bloom is supported by a long, thin stalk which droops alarmingly as soon as the plant is cut, or removed from the ground.  This means that photographing the flower, after transporting it home, is more difficult than usual.  I find that allowing the cut stem (or roots) to stand in water for about an hour revives the little plant, if it is kept beside a sunny window.  Because of the extremely small size of the bloom, quite high magnification is required to fill the frame with the image.
 
A photograph of an entire plant reveals the two possible leaf arrangements:  a whorl of three, (near the flower), and two opposing, (beneath).  The leaves (rounded with triangular tips) may, or may not be attached to the stem by stalks.  I found the plants growing in the grass at the edge of a park.  They were very difficult to see, as their height was about three centimetres and the grass growing around them was several centimetres higher.  Only their bright colour brought them to my attention.




 
From beneath, the five sepals, (modified leaves), can be seen to bisect each pair of petals.  Notice the lighter colour of the back of each petal compared to the front.  Because of this, the deep purple spot on the base of each petal is easier to see.




 
A side view of the bloom shows that the centre, where the petals are fused, is covered with fine, pure white, hairy fibers.  From these fibers project five stamens, and a pistil.




 
The image below shows the positions of these organs, with the pistil in the centre of the flower, and the stamens surrounding it in a ring.




 
A slightly higher magnification reveals more details in the two flowers shown below.








Notice the tiny red hairs that cover the filament supporting each yellow anther (the male, pollen producing organ).  Since scarlet pimpernel flowers do not produce nectar solution, these hairs may serve to attract nearby insects.




 
A microscope with dark-ground illumination shows more detail.  At the top of each image is the pollen encrusted anther.  The red filament supporting the anther can be seen (in the right-hand image) to be comprised of elongated reddish cells with white edges.  The unusual hairs seem to be made up of  a series of globular sections which increase in size away from the filament.




 
A much higher magnification reveals the striations on the surface of these ellipsoidal hair sections.




 
The style and stigma (the female, pollen accepting organ) of the flower is visible in the photomicrograph below.  The style does not have the hairs that are seen on the filaments.  Notice that scarlet pimpernel pollen appears to be ellipsoidal in shape.




 
After the flower has matured and died, the ovary swells and ripens to form a globular seed capsule.  Notice in the image below, that the five sepals remain, as does what is left of  the pistil.  If you look carefully, the forming circular seeds are visible beneath the green translucent membrane.





Scarlet pimpernel propagates entirely by seeds.  The plant dies completely as cold weather arrives.
 
When I started searching for wildflowers to photograph at the beginning of the summer, it was the larger blooms that were my first subjects.  A glint of red in the grass caught my attention one day, and I was shocked to find that I had been walking on these little marvels as I searched.  Obviously not all spectacular flowers are large in size!
 

 
Photographic Equipment

The low magnification photographs in the article were taken using a Nikon Coolpix 4500 with a combination of natural light and the Nikon Cool light SL-1.  Higher magnification images were taken with natural light using a Sony CyberShot DSC-F 717 equipped with a combination of achromatic close-up lenses (Nikon 5T, 6T and shorter focal length achromat) which screw into the 58 mm filter threads of the camera lens.  (These produce a magnification of from 0.5X to 9X for a 4x6 inch image.)  Still higher magnifications were obtained by using a macro coupler (which has two male threads) to attach a reversed 50 mm focal length f 1.4 Olympus SLR lens to the F 717.  (The magnification here is about 13X for a 4x6 inch image.) The photomicrographs were taken with a Leitz SM-Pol microscope (using a dark ground condenser), and the Coolpix 4500. 


A Flower Garden of Macroscopic Delights

A complete graphical index of all of my flower articles can be found here.


The Colourful World of Chemical Crystals

A complete graphical index of all of my crystal articles can be found here.

 All comments to the author Brian Johnston are welcomed.

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Published in the June 2009 edition of Micscape.
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