Monday, March 20, 2017

[Botany • 2017] Manihot pulchrifolius • Morphological Characteristics and Genetic Evidence Reveals A New Species of Manihot (Euphorbiaceae, Crotonoideae) from Goiás, Brazil


Manihot pulchrifolius M.J.Silva


Abstract
During botanical expeditions between 2010 and 2015, as part of a taxonomic study of Manihot in the Midwest region of Brazil, approximately 500 specimens of the genus were collected. Some of these specimens presented similarities to Mirwinii. However, after careful morphological analyses, associated with genetic evidence, we propose here Manihot pulchrifolius as a new species. The new species is described, illustrated, and compared to Mirwinii, its most similar species. Furthermore, geographic distribution, conservation status, and period of flowering and fruiting of the novel species are also provided.

Keywords: Endemism, Manihoteae, mountainous areas, speciation, taxonomy


Figure 2. Manihot pulchrifoliusHabit; note the plant growing between rocky crevices Habit; detail of the waxy stem Portion of the stem showing inflorescences in clusters at the dichotomy of the branches Adult panicle 

 
Figure 2. Manihot pulchrifolius. A Habit; note the plant growing between rocky crevices B Habit; detail of the waxy stem C Portion of the stem showing inflorescences in clusters at the dichotomy of the branches D Adult panicle E Portion of the panicle showing the staminate buds and flowers with vinaceous calyx and yellow margins F Staminate flowers G Pistillate flowers H Mature fruits; note the violet wings.


Manihot pulchrifolius M.J.Silva, sp. nov.

 Type: BRAZIL. Goiás: Mossâmedes, Serra Dourada State Park, near Pedra Goiana, Cerrado rupestre, on rocky crevices, 988 m, 21/XI/2014, fl., M. J. Silva & A. A. Alonso 6232 (holotype: UFG; isotypes: NY, F, K, UB).

Diagnosis: Shrubs up to 2.5 m tall, erect, glabrous; young branches and young leaves reddish to purplish, green-vinaceous to violet; adult leaves 5-lobed at the plant base, 3-lobed along the stem, or rarely unlobed near inflorescence; long racemes or panicles (up to 27 cm long), erect to pendent, axes reddish to purplish; calyx of staminate flowers reddish or purplish with yellow margins, filaments pubescent; bracts and bracteoles of flowers of both sexes reddish to purplish; fruits dark green with violet to purplish wings.


Distribution and Ecology: Manihot pulchrifolius is endemic to the state of Goiás, where it was found growing in Serra Dourada (Figure 3), one of the most beautiful and preserved mountainous areas in the state. This mountain range encompasses the Serra Dourada State Park, an area of over 30,000 hectares protected by law since 1965. The species grows in Cerrado sensu stricto, on rocky outcrops, rocky slopes, and Cerrado rupestre, in clayey, clayey-stony, and sandy soils, or even on rocky crevices, between 900 m and 1,000 m.


 Phenology: The species has been collected with flowers and fruits from November to July. However, the flowers are more usual from January to March, whereas the fruits are more abundant from April to July.

Etymology: The specific epithet “pulchrifolius” alludes to the beautiful foliage of the species, especially in the leaf flushing stage, when the leaves are reddish or purplish to green-vinaceous to violet.


 Marcos José da Silva, Thannya Nascimento Soares and Patrícia Rasteiro Ordiale Oliveira. 2017. Morphological Characteristics and Genetic Evidence Reveals A New Species of Manihot (Euphorbiaceae, Crotonoideae) from Goiás, Brazil.   PhytoKeys. 77; 99-111. DOI: 10.3897/phytokeys.77.11738

   


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