These strange alien structures are among the seeds and pollen conserved at the Kew Millennium Seed Bank . Seeds from more than 10% of the world's flowering plants – around 30,000 species – have been collected in the decade since the bank was established. Kew is celebrating this milestone with an exhibition Banking on Life (4 April – 13 September), and a book of electron micrographs The Hidden Sexuality of Flowers by Rob Kesseler and Madeline Harley (Papadakis, £35)