Flowering plants (angiosperms) form the largest group within the plant kingdom, with at least 352,000 living species. Mosses, liverworts and hornworts (bryophytes) are the next largest group, with approximately 20,000 living species. This is followed by 13,000 species in the lycophytes and monilophytes combined, and 'green algae', also with 13,000 species. Only about 1,000 species of gymnosperms (such as pines and cycads) survive today, but this group was much more diverse and dominant during the Mesozoic Era when dinosaurs were alive. Botanists preserve plant specimens by spreading and drying them on newsprint (often using a plant press). Once dry, the specimens are mounted on white paper and labeled with locality data. You can use the gallery web to compare the morphology of herbarium specimens with photos of the living plant.