Protandry Phenomenon in Hollyhock Plants

June 23, 2020



Photographer: Menashe Davidson 
Summary Author: Menashe Davidson 

Alcea setosa (Bristly Hollyhock) is prominent in springtime in the Middle East, due to its impressively colored and large flowers that are arranged along a conspicuous inflorescence stalk. This beauty triggered me to collect seeds from plants growing in the wild. I then grow them in containers in my apartment garden in Rishon LeZion, Israel, as shown above.

I keep track of them on a daily basis so as to consider all stages of their development. The flowers come in a variety of colors, typically 1 to 4 inches (2.5 to 10 cm) apart. Their blooms start at the bottom of the stem and spiral upward. About every 1-3 days a new flower opens in the spiral on the same stem and stays open a few days.

The Hollyhock is a hermaphrodite plant; the flower possesses both male and female reproductive organs during its lifetime. But by close observation, I learned that the male and female organs mature at different times (so-called dichogamy). In this species, the flower is characterized by the development of male organs (maturation of stamens/pollen), shown in the upper photo, before the appearance of the corresponding female organs (stigma), shown in the flower of the bottom photo. This phenomenon is referred to as protandry. Click here to see more about this.