Tuesday, July 3, 2018

[Botany • 2018] Manihot takape (Euphorbiaceae) • A New Tuberous Subshrub from the Paraguayan Chaco

Manihot takape  De Egea & Peña-Chocarro 
in De Egea Elsam, Carmen Peña-Chocarro, Mereles & Céspedes, 2018 

Manihot takape De Egea & Peña-Chocarro, sp. nov. is described and illustrated as a new species from the Paraguayan Chaco. It was collected while carrying out fieldwork related to the study of the most important Wild Crop Relatives of the country’s flora. Morphological characteristics that differentiate this species from closely related taxa, as well as its habitat, geographical distribution and conservation status are provided.

Keywords: Paraguay, dry Chaco, Manihotae, endemism

Figure 1. Manihot takape.
A Habit (Krapovickas & Cristóbal 44224) B Pistillate flower with calyx open (Krapovickas & Cristóbal 44224) C Staminate flower (Aquino & Quarti 470) D Staminate flower with calyx split and open (Aquino & Quarti 470) E Dried capsule (J. De Egea et al. 1793) F Seed, ventral side (J. De Egea et al. 1793). Drawn by Laura Simón.

Manihot takape De Egea & Peña-Chocarro, sp. nov.
Diagnosis: Subshrubs 0.5−0.8(−1) m tall, all parts glabrous; stems branched from base, suberect to decumbent; petiole attachment basal to occasionally narrowly peltate (less than 0.2 cm from lamina base), lamina unlobed or shallowly to deeply 3(−5)−lobed, several intermediate states found in the same plant; inflorescence a cluster of 2−6 subspicate racemes 14−33 cm long; flowers creamy-white, occasionally reddish, glabrous; pistillate flowers geminate, long pedicellate, sepals distinct, disc plicate; staminate flowers numerous, subsessile, sepals connate 1/4 their length, disc lobulate; capsules light green, unwinged, smooth when fresh, rough when dried.

Figure 3. Manihot takape  (J. De Egea et al. 1793).
 A Habit B Uprooted plant C Roots in cross-section D–E Leaves - note the variability in leaf forms F Immature fruit.

Distribution and ecology: This species has been collected in dry areas of the Paraguayan Chaco, more specifically within the Departments of Boquerón and Presidente Hayes (Fig. 4). These areas are characterised by sandy and loose soils (regosols) resulting from silted palaeo-riverbeds of the Pilcomayo river delta. The species is frequent in open wooded savannahs, locally called espartillares, dominated by the grass Elionurus muticus (Spreng.) Kuntze (espartillo) and scattered with tree species such as Schinopsis cornuta Loes. (Anacardiaceae), Astronium fraxinifolium Schott (Anacardiaceae), Jacaranda mimosifolia D.Don (Bignoniaceae) and Tabebuia aurea Benth. & Hook.f. ex S.Moore (Bignoniaceae). Based on the data available so far, the restricted distribution of Manihot takape could represent an endemism of the dry Chaco. However, more surveys and collections will be needed to confirm the extension of the species distribution range.

Etymology: The specific epithet stems from the vernacular name takape (Guarani language). This word is used for a particular habitat characterised by a wooded savannah or open woodland (Bertoni 1940). The word is also applied to small woody plants (i.e. subshrubs). This is based on the word takã (twig or branch) and the suffix ‘pe’ (short or dwarf). Both meanings fit the newly described species of Manihot.

 Juana De Egea Elsam, María del Carmen Peña-Chocarro, Fátima Mereles and Gloria Céspedes. 2018. Manihot takape sp. nov. (Euphorbiaceae), A New Tuberous Subshrub from the Paraguayan Chaco. PhytoKeys. 103: 1-12. DOI:  10.3897/phytokeys.103.26307

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