Bibliography Spotlight

A Look Inside the Stems of the Charismatic Genus Wisteria

Rosa Nejapa, Universidad Nacional Autónoma de México (UNAM), México

Wisteria is a well-known charismatic genus of lianas naturally occurring in temperate zones of eastern Asia and the eastern USA (however, it is now cultivated across the world given its ornamental value). Previous researchers studied anatomical stem features in genus Wisteria, especially in W. sinensis because of the presence of successive cambia. However, there is a controversy around the origin of successive cambia since different origins have been proposed for W. sinensis.

For my bachelor’s thesis, under guidance of Dr. Marcelo R. Pace (Instituto de Biología, UNAM, México) and in collaboration with Dr. Pablo A. Cabanillas (Cátedra de Dendrología, Facultad de Ciencias Agrarias y Forestales, UNLP, Argentina), we collected ornamental material from W. sinensis in Argentina and the USA, taking advantage of the wide distribution of this cultivated species.

In addition, thanks to loans from the Forestry and Forest Products Research Institute (TWTw) wood collection from Tsukuba, Japan, we obtained stems derived from natural populations of W. brachybotrys and W. floribunda. The work carried out helped us to clarify the origin and development of the successive cambia and to check whether this cambial variant could be a synapomorphy of the genus.

In this study, we demonstrate that three species of Wisteria develop successive cambia in their stems. Through ontogeny carried out with samples cut from apical portions to the thick portions of the stems, we identified that the successive development of cambia was linked to the topological position of the pericyclic fibres, which is a distinct cambial variant for the genus.

Full reference: Nejapa R, Cabanillas PA, Pace MR (2021) Cortical origin of the successive cambia in the stems of the charismatic temperate lianescent genus Wisteria (Fabaceae) and its systematic importance. Botanical Journal of the Linnean Society: boab091, https://doi.org/10.1093/botlinnean/boab091

Adapted from Fig. 2 of Nejapa et al. (2021). Transverse sections of the ontogeny of *Wisteria sinensis* stems. From the onset of secondary growth (A) to stems with two successive cambia (E and F).

Adapted from Fig. 2 of Nejapa et al. (2021). Transverse sections of the ontogeny of Wisteria sinensis stems. From the onset of secondary growth (A) to stems with two successive cambia (E and F).