Stolon-tuber system and phylogeny of orchid-like bladderworts (Lentibulariaceae)

The ‘orchid-like’ bladderworts (Lentibulariaceae) family comprises fifteen species. These robust and mostly epiphytic species were originally grouped within the section Orchidioides and were later split into two sections clades: Orchidioides and Iperua.

Orchid-like Utricularia species. — Orchid-like *Utricularia* species. Sect. *Orchidioides*: (A) *U. quelchii* N.E.Br.; (B) *U. asplundii* P.Taylor; (C) *U. humboldtii* Schomb.; (D) *U. reniformis* A.St.-Hil.; (E) *U. nephrophylla* Benj.; (F) *U. alpina* Jacq.; Sect. *Iperua;* (G) *U. geminiloba* Benj. Arrows denote the crest of the corolla. Photo credits: (A) Martin Hingst; (B) Nicole Rebbert (utricularien.de); (C) Barry Rice; (F) Ron Lane.

Rodrigues et al. provides strong evidence based on DNA sequences and morphology to group the section Orchidioides into the section Iperua. Some morphological characters have appeared two or more times, sometimes being lost again in derivative taxa. The tubers, derivatives of the stolon, provide a valuable phylogenetic character, as well as being important adaptations for water storage: they have been derived from stolons at least twice in the phylogenetic history of ‘orchid-like’ bladderworts.

This paper is part of the Special Issue on Morphology and Adaptation. It is FREE access for a limited period to the end of January 2018. It will then be free access from November 2018.