Lichens are composite organisms consisting of a fungus (the mycobiont) and a photosynthetic partner (the photobiont or phycobiont) growing together in a symbiotic relationship. The photobiont is usually either a green alga (commonly Trebouxia) or cyanobacterium (commonly Nostoc).The morphology, physiology and biochemistry of lichens are very different from those of the isolated fungus and alga in culture. Lichens occur in some of the most extreme environments on Earth
Naples garlic The structure of garlic could be mistaken for exquisite coloured glass. When a tiny stem section is stained with toluidine blue, a dye that builds up in the acidic parts of tissue, nucleic acids show up in blue. The dark spot is a bundle of vascular tissue that carries nutrients and fluids up the stem. The full image is a composite of 55 shots.