Research Triangle: Hydrangea, Caterpillar and Me

Dr Abe V Rotor 

Mophead or Hydrangea (Hydrangea macrophylla) produces blue and pink flowers, and various combinations and hues, that many people think these are varieties or cultivars.  The fact is, the same plant may produce these varying flowers.  

What determines the color of the Hydrangea flower  is aluminum in the soil. Most soils have aluminum but if the soil is alkaline or basic - 6.0 to 6.5 pH (power of Hydrogen) - the plant cannot absorb the aluminum and therefore its flower becomes pink. If the soil is acidic - 5 to 5.5 pH - the plant can absorb the aluminum and its flower becomes blue. A mix of colors is obtained when the pH is between these ranges. This is the secret of gardeners producing Hydrangea of different hues and shades, other that deep blue or old rose pink.  There are other horticultural variations like density of the flower head, height of the plant, branching, variegation, and the like, that make Hydrangea an interesting garden plant.

 And this leads to another phenomenon of nature - dimorphism which is another challenging research. As the name implies a plant or any organism may exhibit  dual characteristics, like
two patterns of leaves, or distinct variations termed as chimaera. In Greek Mythology the Chimaera had three heads - lion, goat, and snake. Its body was also mixed having the front part of a lion, middle of a goat, and snake for a tail.

Hydrangea, Caterpillar and Me 

Came a banded caterpillar heretofore unknown,
     shielded by the plant like its own shell,
and when the clustered flowers one morning opened 
     raced this hairy convict from its cell.

It fed on the leaves, not on the beautiful crown, 
     for whatever reason beauty it spared,
and my inquisitive mind found another enigma, 
     why the flower is neither black nor red.

and whoever this emissary of doom its name,
     family and evolution, deserves study,
what these two creatures mean to each other, 
     to me, and the whole of humanity. ~