Wood anatomy of the tribe Podalyrieae (Fabaceae, Papilionoideae): Diversity and evolutionary trends

Abstract

a b s t r a c t a r t i c l e i n f o Edited by JS BoatwrightDetailed wood anatomical data for 32 species from all nine genera of the tribe Podalyrieae are presented, together with numerical analyses and the mapping of character states onto the latest available molecular phylogeny. It was found that trees (Cadia, Calpurnia and Virgilia) have vessels in small isolated groups, whilst fynbos shrubs (the remaining genera: Amphithalea, Cyclopia, Liparia, Podalyria, Stirtonanthus and Xiphotheca) commonly show highly grouped narrow vessels (frequently in a dendritic pattern), and helical thickening on the vessel walls. Comparisons of the main character state changes with the molecular phylogeny of the tribe show that the wood structure of trees probably represents the basic condition in the tribe; character states present in shrubs appear to have arisen a few times and very likely represent adaptations to seasonal water stress. In general, the wood anatomy is congruent with current subtribal and generic delimitations. Fire-survival strategy is reflected in the rays, with seeders having mostly procumbent cells whilst sprouters have square and upright cells. The close similarity in wood anatomy between Cadia and Calpurnia is in agreement with the transfer of Cadia to the Podalyrieae. A remarkable diversity of crystals was found, including prismatic, acicular and navicular crystals, the last two of which may occur singly or in sheaf-like aggregates.

Crystal types and their distribution in the bark of African genistoid legumes (Fabaceae tribes Sophoreae, Podalyrieae, Crotalarieae and Genisteae)

“…It is noteworthy, however, that navicular crystals occur the bark of many South African genistoids. They were recently found in wood ray cells of two Amphithalea species (Stepanova et al ., ), but they have not been recorded for any other Fabaceae. Among other families, navicular crystals occur in bark of some Lauraceae [the ‘spindelförmige Kristalle’ of Richter ()] and in wood of some Rubiaceae (Jansen et al ., ).…”

“…Four of the seven crystal types occurring in the bark of South African genistoid legumes (prismatic and navicular crystals, acicular crystals in sheaf‐like aggregates and crystal sand) have also previously been found in wood. The crystals were observed in ray cells of the secondary xylem of a few members of Podalyrieae and Crotalarieae (Stepanova et al ., ; Oskolski et al ., ). In these legumes, crystals are therefore more common in bark than in wood.…”

“…Prismatic crystals are common in wood of Sophoreae (Fujii et al ., ; Gasson, , ), but they are rare in wood of Podalyrieae and Crotalarieae, and they are not reported in Genisteae (Stepanova et al ., ; Oskolski et al ., ). The taxonomic distribution of these crystals in bark shows a similar pattern (Fig.…”

“…Investigation of the bark anatomy of Virgilia Lam. (Kotina et al ., ) and the wood anatomy of several members of tribes Podalyrieae and Crotalarieae (Stepanova et al ., ; Oskolski et al ., ) revealed a diversity of crystals warranting more detailed study. The aim of this study is to describe the different crystal types and their distribution in the bark of African genistoid legumes (Fabaceae tribes Sophoreae, Podalyrieae, Crotalarieae and Genisteae) and to evaluate the systematic value of the data.…”

Anatomía comparada de la madera de Cupressaceae y su correspondencia con los estudios de filogenia

“…Estas investigaciones se centran fundamentalmente en angiospermas, como se observan en los estudios de Pace y Angyalossy (2013) y Pace et al (2014) en Bignoniaceae; Stepanova et al (2013) y Oskolski et al (2014) en Fabaceae;o Wagner et al (2014) y Trueba et al (2015 en Piperales.…”