Prosopanche cocuccii (Hydnoraceae): a new species from Southern Brazil

Abstract

Prosopanche cocuccii is described as a new species from Southern Brazil. It resembles P. bonacinae due to the trigonous rhizome and by the general size of the flower organs. Nevertheless, P. cocuccii is distinguished by the main floral morphological characteristics used to differentiate species. In addition, the new species presents some rare characters for the genus, such as a highly branched rhizome and flowers usually grouped in fascicles. We provide a description, illustrations, field photographs, morphological details under the stereomicroscope, and comments on habitat, ecology, distribution, and conservation of the new species, as well as an updated key for the genus Prosopanche. In addition, we identified that P. cocuccii produces a large number of rhizomes and fruits for each single host specimen of tobacco (Nicotiana tabacum), which resulted in a decrease in height and growth of its only known host plant.

Prosopanche: A remarkable genus of parasitic plants

“…In the following century, new species and varieties were described across Argentina and Paraguay, all of which were later synonymised under Prosopanche bonacinae and P. americana by Cocucci in 1965. Since then, five new species have been described across Central and South America: Prosopanche costaricensis (G omez & G omez-Laurito, 1981), Prosopanche caatingicola (Machado et al, 2012), Prosopanche panguanensis (Martel et al, 2018), Prosopanche demogorgoni (Funez et al, 2019) and Prosopanche cocuccii (de Carvalho et al, 2021).…”

“…The entirely holoparasitic family Hydnoraceae contains just two genera, with a disjunct distribution spanning South and Central America ( Prosopanche : seven species; de Carvalho et al, 2021) and Africa and the Arabian Peninsula ( Hydnora : eight species; Bolin et al, 2018). Both genera share the same basic body plan and holoparasitic habit but vary in certain morphological and ecological characters, including host preference.…”

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Prosopanche de Bary (Hydnoraceae) is a remarkable genus of subterranean holoparasitic plants native to South America and Costa Rica (Figure 1). There are currently seven recognised species (Figure 2), three of which were described in the last 4 years (de Carvalho et al, 2021). All seven species have highly reduced vegetative bodies and have lost leaves and functional roots completely.

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“…Some Prosopanche are harvested and sold for their edible fruits, or their rhizomes, which are purported to have anti-asthmatic properties or are used as an expectorant (Cocucci, 1965;Cocucci & Cocucci, 1996).The last comprehensive of monograph of Prosopanche was written in 1965 by A. Cocucci, in which he concluded there were just two species in the genus. Recent work has focused on their ecology, for example, interactions between Prosopanche and the associated specialist Hydnorobius weevils that interact with them (Ferrer & Marvaldi, 2010;Sequeira et al, 2018), or the discovery of new species; otherwise, Prosopanche has received very little attention in the literature in the last 60 years (de Carvalho et al, 2021). Furthermore, Prosopanche has never been cultivated outside of its native range (Thorogood et al, 2022).…”

Structural Plastome Evolution in Holoparasitic Hydnoraceae with Special Focus on Inverted and Direct Repeats

“…Hydnora and its eight known species ( Bolin et al 2018 ) are found exclusively in the Old World, in Central and South Africa and Madagascar ( Musselman and Visser 1989 ). The seven species of genus Prosopanche are found in the New World, in Central and South America ( Gómez-Pignataro and Gómez-Laurito 1981 ; Musselman and Visser 1989 ; De Carvalho et al 2021 ). Hydnora and Prosopanche have an estimated crown group age of ∼55 Ma ( Naumann et al 2013 ), but could potentially be as old as the separation of the African and South American continent.…”