Chandrakantani flowers and Suryakanthani flowers

What key factor influences the timing of flower opening, and who was the first to explore this phenomenon in human history? 

The concept was first discussed by Parashara Acharya in Vrkshayurveda, a book that dates back to the First BC.

W. W. Garner and H. A. Allard later described the phenomenon, now known as photoperiodism, in 1920.

Parashara Acharya's Vrkshayurveda categorizes flowers into two groups based on their lunar and solar connections.

 The nocturnal blooming of Chandrakantani flowers is attributed to the moon's influence, with a predominance of soma. 

The diurnal blooming of Suryakanthani flowers is attributed to the sun's influence, exhibiting Surya predominance.

" पुष्पं द्विविधं विद्यात् सोमसूर्यसम्बन्धात् । 

तत्र पुष्पाणि यानि विकशितानि रजन्यां 

तानि चन्द्रकान्तगणीयानि भवन्ति निशा हि चन्द्रबलवत्त्वात् । 

यानि तु पुष्पाणि दिवायां विकसन्ति 

तानि रविकान्तगणीयानि दिवसं हि रविबलत्त्वात् ।। "

By Ajayan Sir