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| Solanum plastisexum Martine & McDonnell
in McDonnell, Wetreich, Cantley, Jobso & Martine, 2019.
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Abstract
A bush tomato that has evaded classification by solanologists for decades has been identified and is described as a new species belonging to the Australian “Solanum dioicum group” of the Ord Victoria Plain biogeographic region in the monsoon tropics of the Northern Territory. Although now recognised to be andromonoecious, Solanum plastisexum Martine & McDonnell, sp. nov. exhibits multiple reproductive phenotypes, with solitary perfect flowers, a few staminate flowers or with cymes composed of a basal hermaphrodite and an extended rachis of several to many staminate flowers. When in fruit, the distal rachis may abcise and drop. A member of Solanum subgenus Leptostemonum, Solanum plastisexum is allied to the S. eburneum Symon species group. Morphometric analyses presented here reveal that S. plastisexum differs statistically from all of its closest relatives including S. eburneum, S. diversiflorum F. Meull., S. jobsonii Martine, J.Cantley & L.M.Lacey, S. succosum A.R.Bean & Albr. and S. watneyi Martine & Frawley in both reproductive and vegetative characters. We present evidence supporting the recognition of S. plastisexum as a distinctive entity, a description of the species, representative photographs, a map showing the distribution of members of the S. eburneum species group and a key to the andromonoecious Solanum species of the Northern Territory of Australia. This new species is apparently labile in its reproductive expression, lending to its epithet, and is a model for the sort of sexual fluidity that is present throughout the plant kingdom.
Keywords: New species, andromonoecy, Solanaceae, Leptostemonum
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| Figure 2. Closely related species of andromonoecious bush tomatoes included in this study. A Solanum jobsonii B S. watneyi C S. succosum D Solanum plastisexum E S. diversiflorum and F S. eburneum. |
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| Figure 1. Morphology and the earliest-known herbarium specimen of Solanum plastisexum. A Flowering stem with a single staminate flower in 2016 B Mature fruit C Erect inflorescences bearing staminate flowers in 2018 and D Specimen collected by P. Latz in 1974, held at DNA and annotated by D. Symon with an annotation indicating his confusion about the reproductive morphology of the specimen (male rachis visible above fruit on far left). |
Solanum plastisexum Martine & McDonnell, sp. nov.
Diagnosis: Like Solanum eburneum, Solanum watneyi and Solanum succosum, but differing by having elliptic, unlobed (or rarely very shallowly lobed) leaves, small apical leaves, long calyx lobes on the staminate flowers and fully erect staminate inflorescence branches.
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Etymology: The name is based on the Latin “plastus” (“deceptive,” but derived from the Greek “plastikos/plasticos/plasticus” for “able to be molded, changeable”) and the Latin “sexus” for sex. We suggest the use of Dungowan Bush Tomato for the common name of this species, which refers to the cattle station on which the majority of the collections have been made.
Angela J. McDonnell, Heather B. Wetreich, Jason T. Cantley, Peter Jobso and Christopher T. Martine. 2019. Solanum plastisexum, An Enigmatic New Bush Tomato from the Australian Monsoon Tropics Exhibiting Breeding System Fluidity. PhytoKeys 124: 39-55. DOI: 10.3897/phytokeys.124.33526
Meet Australia’s New Sex-Changing Tomato: Solanum plastisexum nyti.ms/2MSzL01
Scientists challenge notion of binary sexuality with naming of new plant species eurekalert.org/e/9J0Z via @Pensoft @EurekAlert
