Review: The hornworts: morphology, evolution and development (New Phytol.)

Bryophytes and vascular plants share a land plant as a common ancestor, but they have evolved independently for more than 400 million years. Recent genomic studies of model bryophytes, particularly mosses and liverworts, have provided insights into this ancient common ancestor. Here, Frangedakis et al. profile the newest model bryophyte, the hornwort Anthoceros agrestis, which harbors a number of unusual features for a land plant, including a continuously-growing sporangium, usually a single chloroplast per cell that may include a pyrenoid, and symbiotic relationships with endophytic cyanobacteria as well as mycorrhizal fungi. This review discusses each of these features as well as the hornwort lifecycle and development, and what is known about each of their molecular bases as compared to other model species. (Summary by Mary Williams @PlantTeaching) New Phytol. 10.1111/nph.16874