When you pick a daisy, you are actually picking hundreds of flowers at the same time. That's because daisies have evolved a special trick, which is to hide a whole field of flowers in the head of what seems to be a single bloom. In this video, University of Cambridge plant biologist Beverley Glover shows you a microscopic image of a daisy that reveals the truth about these deceptively plain flowers.
The flowering plants (Angiosperms) form the dominant vegetation over most of the Earth's land surface. They are found in all habitats except the Antarctic, and can tolerate an extraordinarily wide range of environmental conditions. All major human food crops are Angiosperms. We are interested in the evolution and development of the flower, one of the defining features of Angiosperms. The evolution of flowers changed the way in which plants reproduced, allowing them to use animals to carry their pollen around. Our research is particularly focussed on understanding how the features that make flowers attractive to insects evolved, and what the genetic control of their development is. We hope to be able to use this knowledge to improve pollination and yield of important crop plants and to help protect the great diversity of flowers and insect pollinators in the wild.
This image of a developing daisy flower head is part of our work on understanding different ways of attracting pollinators. All the plants in the daisy family use the same trick – by clustering together many tiny flowers they produce a structure that looks just like a single big flower. The daisies that grow in our lawns contain two different types of flowers – central radially symmetrical yellow ones, and an outer ring of bilaterally symmetrical white ones with a massively elongated petal structure. In this Scanning Electron Micrograph you can see the central yellow flowers at a very early stage of development, with the petals still folded over the centre of each little flower.
Each of the round structures that will go on to be an individual flower is about 200 micrometers in diameter, or 1/5 of a millimeter. The whole image is about 1mm across.
Learn more via Cambridge's Department of Plant Sciences.
Music by Peter Nickalls
This is the fifth in a series of videos called Under the Microscope, which io9 is posting in partnership with scientists at University of Cambridge. Under the Microscope is a collection of videos that capture glimpses of the natural and artificial world in stunning close-up. They will be released every Monday and Thursday for the next couple of months, and you can see the whole series here.