Asteraceae
Lab dissection (Gerbera)
Gerbera
Collection of 4 differents flowers
Ray flowers
Flower head: Disc flower and receptacle
Ovary
Dis flower with hairs for pollen
Disc flower
Plate: drawing and observations
Scientific classification
GERBERA
Notes
25.000 species distributed worldwide.
It's a composite of flowers (what appears to be a flower is actually a multiple false flower). Every petal is a flower!
They appeared 20 million years ago and are among the most evolved plants.
Almost complete loss of sepals (calyx).
Inferior ovary composed of 2 carpels.
Another caracteristic includes having fused anthers forming a cylinder around the style (syngenesious condition).
Largest dicot family.
To protect itself from self pollination stigma is closed as it grows up past the anthers - don't open until pollen production is over.
Pollination is in most cases entomophilous.
On the field...
Dandelion flower is an Asteracea flower.
Asteracea before floraison.
I did some tests with aerogel (frozen smoke).
The artichoke flower is also an Asteraceae!
Sources
Botanique, systématique moléculaire, Guignard and Dupont (2005)
The Science behind Flowers, Dick Rauh (2020).
Botany Illustrated. Introduction to Plants, Major Groups, Flowering Plant Families, by Janice Glimn-Lacy and Peter B. Kaufman (2006).
French wikipedia page: https://fr.wikipedia.org/wiki/Asteraceae
Susannah Graedel's plate.