Annals of Botany 117: 811–832, 2016 doi:10.1093/aob/mcv172, available online at www.aob.oxfordjournals.org REVIEW: PART OF A SPECIAL ISSUE ON DEVELOPMENTAL ROBUSTNESS AND SPECIES DIVERSITY Evolution of unusual morphologies in Lentibulariaceae (bladderworts and allies) and Podostemaceae (river-weeds): a pictorial report at the interface of developmental biology and morphological diversification Rolf Rutishauser* Institute of Systematic Botany, University of Zurich, Zurich, Switzerland * For correspondence. E-mail
[email protected] Received: 30 July 2015 Returned for revision: 19 August 2015 Accepted: 25 September 2015 Published electronically: 20 November 2015 Background Various groups of flowering plants reveal profound (‘saltational’) changes of their bauplans (archi- tectural rules) as compared with related taxa. These plants are known as morphological misfits that appear as rather Downloaded from large morphological deviations from the norm. Some of them emerged as morphological key innovations (perhaps ‘hopeful monsters’) that gave rise to new evolutionary lines of organisms, based on (major) genetic changes. Scope This pictorial report places emphasis on released bauplans as typical for bladderworts (Utricularia,approx. 230 secies, Lentibulariaceae) and river-weeds (Podostemaceae, three subfamilies, approx. 54 genera, approx. 310 species). Bladderworts (Utricularia) are carnivorous, possessing sucking traps. They live as submerged aquatics (except for their flowers), as humid terrestrials or as epiphytes. Most Podostemaceae are restricted to rocks in tropi- http://aob.oxfordjournals.org/ cal river-rapids and waterfalls. They survive as submerged haptophytes in these extreme habitats during the rainy season, emerging with their flowers afterwards. The recent scientific progress in developmental biology and evolu- tionary history of both Lentibulariaceae and Podostemaceae is summarized.