Manihot pulchrifolius M.J.Silva, 2017

Silva, Marcos Jose da, Soares, Thannya Nascimento & Oliveira, Patricia Rasteiro Ordiale, 2017, Morphological characteristics and genetic evidence reveals a new species of Manihot (Euphorbiaceae, Crotonoideae) from Goias, Brazil, PhytoKeys 77, pp. 99-111 : 102-103

Manihot pulchrifolius M.J.Silva sp. nov. Figures 1 , 2

Type.

BRAZIL. Goiás: Mossâmedes, Serra Dourada State Park, near Pedra Goiana , Cerrado rupestre, on rocky crevices, 16°04'40,5"S, 50°11'20.8"W, 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.

Description.

Shrubs 1-2.5 m tall, monoecious, erect; stems and adult branches robust, cinereous, glabrous, waxy, and glossy; young branches and young leaves reddish to purplish, green-vinaceous to violet, including axes of inflorescences and petioles; branches dichotomously branched near apex, sometimes pendent in specimens taller than 1.2 m; latex yellowish, copious; petiole 4.5-13 cm long, robust, canaliculated above, dark purplish to violet. Stipules 1.9-2 cm long, linear, entire to discreetly serrate, caduceus. Leaves in alternate spiral arrangement; lamina firmly chartaceous, glabrous on both surfaces, the basal ones 5-lobed, the others 3-lobed, or unlobed near inflorescence, lobes conspicuously overlapping at sinus, 8.4-15 × 4.5-10 cm, widely oblong-obovate, elliptic-obovate to obovate, apex cuspidate, sometimes oblique, base cordate; venation camptodromous-brochydodromous, primary and secondary veins pinkish, purplish, violet, or rarely yellowish, the primary ones prominent on both surfaces, the secondary ones subparallel to the midrib, impressed on both surfaces, bifurcate or not at apex; adaxial surface dark green and opaque in adult leaves, or light green, castaneous, reddish to purplish in young leaves; abaxial surface opaque green to cinereous with a smooth wax pattern; racemes 5-17 cm long, or panicles 17-24 cm long, laxy, terminal or in the dichotomy of the branches, solitary or in clusters of 2 or 3, erect to pendent, bisexual; if racemes, they have two opposite pistillate flowers at the base and another staminate; if panicles, the secondary axes are similar to racemes, but sometimes without pistillate flowers at the base of secondary axes. Staminate flowers 21-25 mm long; buds 9-10 mm long, globoid to orbicular, reddish, obtuse at apex, glabrous and waxy externally; bracts 11-12 × 2.5-3.3 mm, oval, elliptic, entire, acuminate at apex, reddish, persistent, glabrous on both surfaces; bracteoles 5.7-7 × 1-2 mm, linear, subalternate, distributed on the lower third of the pedicel, glabrous on both surfaces, margins entire, not ciliate, caduceus; pedicels 8.5-12 mm long, cylindrical, reddish to purplish, waxy, glabrous; calyx 12-15 × 10-11 mm, widely campanulate, reddish with yellowish margins, glabrous externally and shortly tomentose internally, lobes widely triangular to ovate, apex obtuse; stamens 10, in two whorls of five, filaments 8-8.2 mm long, pubescent distally, anthers 3-3.2 mm long, oblongoid, yellowish; disk 10-lobed, dark yellow, lobes rounded. Pistillate flowers 19-25 mm long; buds 6-7 mm long, ovoid, glabrous, yellowish with reddish spots; bracts 8-15 × 2.4-3 mm, oval-lanceolate to lanceolate, vinaceous to purplish, entire, acuminate at apex, persistent, glabrous, not ciliate; bracteoles 10-12 × 2-3.5 mm, lanceolate, margin discreetly serrate, similar to the bracts in color; pedicels 13-16 mm long, cylindric-clavate, glabrous, greenish, sepals 8.2-11 × 3.3-5 mm, ovate to oval-elliptic, rarely lanceolate or triangular, shortly pubescent in the upper third internally, apex obtuse, yellowish with reddish pigmentation, margins involute; ovary 3-3.2 × 2-2.1 mm, oblongoid to globoid, glabrous, not winged, green, disk discreetly lobed, yellowish, styles 3, conspicuously united at the base, free portion 2.1-2.2 mm long, with papilose apex. Capsules 12-14 × 16-17 mm, globoid, smooth, glossy, winged, with septicidal and loculicidal dehiscence, green to purplish, slightly glossy. Seeds 8-10 × 4-5 mm, oblongoid, cinereous, with dark spots; caruncle 0.9-1 mm long, sessile, reniform, cream to whitish.

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.

Conservation status.

Given that the populations have more than 50 individuals and the vegetation where they grow is commonly found in the central part of the state of Goiás (in the municipality of Goiás and neighboring municipalities), we consider Manihot pulchrifolius as Least Concern (LC) according to IUCN (2016).

Specimens examined.

BRAZIL. Goiás: Mossâmedes, Serra Dourada State Park, on the way to Pedra Goiana , 9 Dec 2009, fl., A. M. Teles 658 (UFG); ib., 30 Oct 2010, fl., M. J. Silva et al. 3138 and 3139 (UFG); ib., near Pedra Goiana , 16°04'34,7"S, 50°11'28"W, 994 m, 21 Nov 2014, fl., M. J. Silva & A. A. Alonso 6234 and 6235 (UFG); ib., 16°04'40,5"S, 50°11'20.8"W, 988 m, 21 Nov 2014, fl., M. J. Silva & A. A. Alonso 6230 and 6231 (UFG); District of Mirandopolis , Rildo Nogueira farm, 27 Nov 2010, fl., M. J. Silva 3194 and 3198 (UFG); ib., near the first gate that leads to the park headquarters, 16°04'46,9"S, 50°11'28,4"W, 985 m, 29 Jan 2011, fl., fr., M. J. Silva 3372 (UFG); ib., 4 km above the Piçarrão stream, 16°04'17,4"S, 50°11'26,1"W, 993 m, 30 Apr 2011, fl., fr., J. E. C. Júnior 15 and 18 (UFG); region after Areal, 16°04'00,9"S, 50°10'8,9"W, 953 m, 28 May 2011, fr., J. E. C. Júnior 51 (UFG) .

Figures

Figure 1. Manihot pulchrifolius. A Flowering branch B Stipule C Staminate bud D Staminate bract E Staminate bracteole F Staminate flower G Staminate flower with calyx split and open H Stamen I Pistillate bud J Pistillate bract K Pistillate bracteole L Pistillate flower M Fruit N Seed, ventral side O Seed, dorsal side. Drawn by Cristiano Gualberto from the holotype.

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.

Figure 3. Distribution map of sampled populations highlighting the population of Mossamedes (= Manihot pulchrifolius). The other populations correspond to Manihot irwinii.