Manihot montana M.J. Silva, 2019

Silva, Marcos José Da, Souza, Alessandro Oliveira De, Alonso, Alexandre Antônio & Esser, Hans-Joachim, 2019, Manihot montana, a new species of Manihot sect. Graciles (Euphorbiaceae) from the Brazilian savannas, Phytotaxa 403 (3), pp. 210-220 : 211-215

Manihot montana M.J. Silva , sp. nov. ( Figs. 1 , 2 )

Type:— BRAZIL. Goiás: Mossâmedes, Parque Estadual da Serra Dourada, in Cerrado type vegetation, lado direito da estrada ca. 200 m a partir da porteira que leva a casa dos vigilantes, 8 December 2015 (fl., fr.), M. J. Silva & A. A. Alonso 7191 (holotype UFG 67747 !; isotype: UFG67748 !) .

Diagnosis:— Manihot montana resembles Manihot paviifolia by having subshrubby habit, bracts of the flowers of both sexes persistent, staminate calyx green-yellowish with purplish pigmentation, pistillate calyx glabrous on both surfaces, and yellowish without purplish pigmentation, but it can be distinguished from it by leaves 3–5-lobed with secondary veins impressed (vs. 5–7, prominent in M. paviifolia ), flowers aggregated at the apex of a pendulous inflorescence with a raceme-like, corymbiform, or paniculate aspect (vs. regularly distributed along of pendent inflorescence with a raceme-like), staminate calyx campanulate (vs. tubulose), staminate bracts lanceolate (vs. widely ovate, elliptic and obovate, pistillate sepals 1.3–13.8 cm long (vs. 0.9–1 cm), and seed 7–7.9 mm long, the caruncle obtuse (vs. 5 mm, hat-shaped).

Subshrubs to shrubs 0.6–1.6 m tall, erect, caespitose or not, glabrous. Stems unbranched or dichotomously or trichotomously branched near the apex; adult branches light to dark brownish or reddish, sometimes discretely exfoliating; young branches greenish to purplish or vinaceous; latex clear to yellowish. Stipules 2–5 × 0.1–0.2 mm, linear-lanceolate, margin entire, nearly caducous; petiole (1.7–)2.2–6.3(–9.5) cm long, angulate, sulcate above. Leaves spirally alternate, distributed regularly along the branches; blades 11.5–14(–18.5) cm long, basal ones 3(–5)-lobed, carthaceous; discolour, upper surface dark green, lustrous, lower surface cinereous to whitish; lobes (8.2–)5.5–7.8(– 10.3) × (1.5–) 2.1–4 cm, elliptic to widely elliptic or elliptic-obovate, apex acuminate and mucronulate, margin entire, revolute, base oblique in lateral lobes and cuneate in the central lobes, venation camptodromous to brochidodromous, primary and secondary veins yellowish, the primary ones prominent on both surfaces, the secondary ones arching to the midrib, impressed on both surfaces. Inflorescence 5.5–11.5 cm long, raceme-like, corymbiform, or paniculate, 11.5–12 cm long, always bisexual, solitary or 2 or 3 in a cluster arising from a dichotomy or trichotomy of the branches, or less often terminal, glabrous, greenish-purplish. Staminate buds 9.9–10 × 5.9–6.1 mm, ovoid to oblong-ovoid, greenish or yellowish with purplish pigmentation; bracts 9.2–13(–16) × 1.2–2.8 mm, lanceolate to oblong-elliptic, foliaceous, persistent, apex acute, margin entire or rarely sparsely and irregularly serrate, glabrous on both surfaces, purplish; bracteoles 3.0– 3.4 mm long, linear, membranaceous, caducous, margin entire, opposite, glabrous, purplish; flowers 29–32 mm long; pedicels 15.0– 15.1 mm long, cylindrical, glabrous, yellowish; calyx 16–18 × 9.9–10 mm, campanulate, green-yellowish with purplish pigmentation, shortly tomentose internally, lobes 7.1–7.2 × 2.8–2.9 mm, triangular, apex obtuse, base truncate; stamens 10, in two whorls of 5, filaments 3.9–4 mm or 7.9–8.0 mm long, glabrous, anthers oblong, bright yellow; disc 10-lobed, dark yellow, tomentose. Pistillate buds 8.0–8.7 × 3.0– 3.2 mm, ovoid, greenish with purplish pigmentation; bracts 9–12 × 2.6–2.7 mm, elliptic, apex acuminate, margin entire or irregularly serrulate, similar to the staminate bracts; bracteoles 10.9–11 × 0.8–0.9 mm, similar to the staminate bracteoles; flowers 2.6–3.9 cm long; pedicels 1.2–2.6 cm long, cylindrical, glabrous, green; sepals 13–13.8 × 3.6–4.0 mm, elliptical to ellipticallanceolate, yellowish without purplish pigmentation, glabrous on both surface, apex discretely acuminate, margin convolute, base truncate; ovary 3.1–3.2 × 2.8–2.9 mm, sub-globose, light green, disc sub-entire and slightly undulate, dark yellow; styles 3, united at base, apex hightly lobed. Fruiting pedicel 3.5–5.0 cm long; capsules 1.2–1.5 × 0.9–1 cm, widely oblongoid to sub-globose, smooth, without ribs, glabrous, dehiscence septicidal and loculicidal, with a white stripe along the locules when mature. Seeds 7.0–7.9 × 4.9–5.0 mm, oblong, cinereous with black spots, caruncle obtuse ca. 1.9 mm long, cream to yellowish.

Distribution, ecology and phenology:— Manihot montana has hitherto only been collected in the Serra Dourada in Goiás state ( Fig. 3), which comprises the Serra Dourada State Park, an area legally protected by the Brazilian government. It grows in open areas of Cerrado and Cerrado rupestre vegetation on sandy and clayey soils or rock crevices. It occurs sympatrically with M. gracilis Pohl (1827: 23) subsp. varians ( Pohl 1827: 53) Rogers & Appan (1973: 160) and M. pentaphylla Pohl (1827: 53) subsp. tenuifolia ( Pohl 1827: 38) Rogers & Appan (1973: 153) , at elevations of 788–1017 m. It flowers and fruits from November to April, the fruits being more common in April.

Conservation status:— Manihot montana has an extent of occurrence of 175 km 2 and is restricted to the Serra Dourada State Park (SDSP), in the central part of Goiás state. This park comprises approximately 30,000 hectares and is covered mainly by Cerrado and Cerrado rupestre vegetation, but also gallery forests, seasonal dry forests and grassland savannas. Therefore, despite the small extent of occurrence of 175 km 2, we consider its conservation status as “Least Concern’’ (LC) ( IUCN 2014), because the species is abundant and grows in different vegetation types.

Etymology:—The epithet alludes to the habitat where this species grows, in a montane area.

Additional specimens examined:— BRAZIL. Goiás: Mossâmedes, Parque Estadual da Serra Dourada , arredores da Pedra Goiana, 25 November 2010 (fl., fr.), M. J. Silva 3167 ( UFG) ; ibid., Distrito de Mirandópolis , próximo à Fazenda do senhor Rildo, 27 November 2010 (fl.), M. J. Silva 3192 ( UFG) ; transição mata seca para cerrado na estrada que leva à sede do parque, 16º5’21,2”S, 50º11’51”W, 788 m, 28 January 2011 (fl., fr)., M. J. Silva 3327 ( UFG) ; ibid., entre fendas de arenito, 29 January 2011 (fl., fr.), M. J. Silva 3362 ( UFG) ; próximo ao Areal, 26 March 2011 (fr.), M. J. Silva 3511 ( UFG) ; imediações da sede do PESD, 16º4’47,2”S, 50º11’32,6”W, 987 m, 30 April 2011 (fl.), J. E. C. Júnior 27 ( UFG) ; Serra Dourada, Parque Estadual da Serra Dourada , estrada em direção aos alojamentos do parque, ca. 1 km da porteira que dá acesso aos mesmos, 15°48’18,8”S, 48°50’01,9”W, 12 January 2015 (fl.), R. C Sodré 1640 ( UFG) ; Serra Dourada, Parque Estadual da Serra Dourada , lado direito da estrada ca. 200 m a partir da porteira que leva a casa dos vigilantes, 8 December 2015 (fl., fr.), M. J. Silva & A. A. Alonso 7190 ( UFG) ; Serra Dourada, Parque Estadual da Serra Dourada , 300 m acima da porteira de acesso ao casa dos vigilantes, 8 December 2015 (fl.), M. J. Silva & A. A. Alonso 7192 ( UFG) ; ibid., área lateral esquerda da primeira porteira que leva ao alojamento dos vigilantes do PESD, 15°48’18,8”S, 48°50’01,9”W, 8 December 2015 (fl.), M. J. Silva & A. A. Alonso 7193 ( UFG) ; Serra Dourada, Parque Estadual da Serra Dourada , 150 m a partir da lateral esquerda da primeira porteira que leva a casa dos vigilantes, 8 December 2015 (fl.), M. J. Silva & A. A. Alonso 7194 ( UFG) ; Serra Dourada, Parque Estadual da Serra Dourada , 250 m a partir da lateral esquerda da primeira porteira que leva a casa dos vigilantes 8 December 2015 (fl.), M. J. Silva & A. A. Alonso 7195 ( UFG) ; Serra Dourada, Parque Estadual da Serra Dourada , caminho para a cidade de pedra cerca de 800 metros a partir da casa dos vigilantes, 8 December 2015 (fl.), M. J. Silva & A. A. Alonso 7198 ( UFG), M. J. Silva & A. A. Alonso 7199 ( UFG) ; Serra Dourada, Parque Estadual da Serra Dourada, Parque Estadual da Serra Dourada, Cidade de Pedra , 9 December 2015 (fl.), M. J. Silva & A. A. Alonso 7200 ( UFG) ; Serra Dourada, Parque Estadual da Serra Dourada , ca. 1 km a sudoeste do alojamento em afloramento de rochas, 9 December 2015 (fl.), M. J. Silva & A. A. Alonso 7208 ( UFG) ; Serra Dourada, Parque Estadual da Serra Dourada, Parque Estadual da Serra Dourada, Cidade de Pedras , 16°04’40”S, 50°11’29”W, 984 m, Cerrado rupestre, 15 March 2016 (fl., fr.), M. J. Silva & A. A. Alonso 7360 ( UFG), M. J. Silva & A. A. Alonso 7361 ( UFG), M. J. Silva & A. A. Alonso 7362 ( UFG), M. J. Silva & A. A. Alonso 7363 ( UFG) ; Serra Dourada, Parque Estadual da Serra Dourada, imediações da Pedra Goiana, 16°04’42”S, 50°11’29”W, 983 m, Cerrado rupestre, próximo a córrego, sobre solo arenoso, 15 March 2016 (fl., fr.), M. J. Silva & A. A. Alonso 7364 ( UFG), M. J. Silva & A. A. Alonso 7365 ( UFG), M. J. Silva & A. A. Alonso 7366 ( UFG) ; Serra Dourada, Parque Estadual da Serra Dourada , 600 metros a partir da primeira porteira que leva a sede do Parque, Cerrado rupestre, 15 March 2016 (fl., fr.), M. J. Silva & A. A. Alonso 7367 ( UFG), M. J. Silva & A. A. Alonso 7368 ( UFG), M. J. Silva & A. A. Alonso 7370 ( UFG), M. J. Silva & A. A. Alonso 7373 ( UFG) ; Serra Dourada, Parque Estadual da Serra Dourada , ca. 250 metros abaixo da casa dos vigilantes, Cerrado sensu stricto, 15 March 2016 (fl.), M. J. Silva & A. A. Alonso 7371 ( UFG) ; ibid., ca. 1 km a partir da sede do Parque em direção a pista de Asa Delta, 16°04’19”S, 50°11’02”W, 1017 m, 15 March 2016 (fl., fr.), M. J. Silva & A. A. Alonso 7374 ( UFG), M. J. Silva & A. A. Alonso 7375 ( UFG), M. J. Silva & A. A. Alonso 7377 ( UFG), M. J. Silva & A. A. Alonso 7378 ( UFG), M. J. Silva & A. A. Alonso 7379 ( UFG) ; Serra Dourada, Parque Estadual da Serra Dourada, Região do Areal , Cerrado Rupestre de encosta, 16°03’58”S, 50°10’25”W, 978 m, 15 March 2016 (fl.), M. J. Silva & A. A. Alonso 7380 ( UFG), M. J. Silva & A. A. Alonso 7381 ( UFG), M. J. Silva & A. A. Alonso 7382 ( UFG), M. J. Silva & A. A. Alonso 7383 ( UFG), M. J. Silva & A. A. Alonso 7384 ( UFG) .

Figures

FIGURE 1. Manihot montana.A. Flowering branch. B. Portion of inflorescence. C. Staminate bract. D. Staminate bracteole.E. Staminate bud. F. Staminate flower. G. Staminate flower with calyx split open. H. Pistillate bract. I. Pistillate bracteole. J. Pistillate bud. K. Pistillate flower. L. Fruit. M. Carpophore. N. Mericarp, ventral side. O. Seed, ventral side. P. Seed, dorsal side. Drawn by Cristiano Gualberto from the holotype.

FIGURE 2. Manihot montana. A. Habit.B. Portion of the stem showing inflorescences, young fruits, and staminate flowers. C. Portion of an inflorescence showing staminate flowers and buds. D. Aspect of the bracts on inflorescence. E. Staminate flowers. F. Pistillate flowers. Photos by Marcos José da Silva.