Plant of the Month — April 2013

Solanum zoeae R.L.Barrett

Find out more about Solanum zoeae R.L.Barrett

Solanum zoeae is a new species of bush tomato from the North Kimberley in Western Australia, first collected in 2008. Little fertile material could be located at the time, however, the leaf shape and very fine indumentum suggested that it might represent a distinct taxon. Heavy wet season rains associated with Cyclone Lua in March 2012 extended the flowering season and a return visit to the original location three months later led to the collection of flowering and fruiting material, allowing the species to be formally described.

Solanum zoeae is closely related to S. leopoldense but distinguished by the larger, erect habit and thick, woody stem bases. The leaves of S. zoeae are more deeply lobed with a very fine but very dense stellate indumentum. Additionally, the segments (rays) of the individual stellate hairs are clearly demarcated (constricted at the base), the glandular hairs on the leaf margins and veins are stalked and the seeds are more finely reticulate.

Flowering and fruiting of Solanum zoeae occurs mainly late in the wet season and is finished by May to June depending on seasonal fluctuation. Listed as Priority One under DEC Conservation Codes for Western Australian Flora, this species is only known from the vicinity of the type collection over a range of about 1 km. About 200 plants have been observed in this area and the surrounding habitat in most directions is unsuitable for this species, but there is potentially suitable habitat to the north of the known population.

The generic name was coined by Pliny the Elder (23-79 AD) for the plant ‘strychnos’, possibly Solanum nigrum. Its derivation may come from the Latin word sol meaning ‘sun’ referring to its preference for full sun, or perhaps from solare referring to its soothing effect after ingestion. As this new species was discovered on the same day and in the same place that its author met Zoe Emily Davies, his future wife, it is named for her.

Solanum zoeae was described by Russell Barrett in our journal Nuytsia, from which much of this text is transcribed. The paper also includes a number of detailed colour plates, SEM images and a key to Solanum species in the Kimberley region.

Photo: R. Barrett

Find out more about Solanum zoeae R.L.Barrett

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