Manihot kalungae M. J. Silva & R. C. Sodré, 2013

Silva, Marcos José Da, Sodré, Rodolfo Carneiro & Almeida, Laura Cristina Da Silva, 2013, A new endemic species of Manihot (Euphorbiaceae s. str.) from the Chapada dos Veadeiros, Goiás, Brazil, Phytotaxa 131 (1), pp. 53-57 : 54-56

Manihot kalungae M. J. Silva & R. C. Sodré , sp. nov. ( Fig. 1 )

This new species is similar to M. populifolia Pax in its habit and general leaf shape. M. kalungae , however, presents persistent stipules (vs. caducous stipules), basal attachment of the petiole (vs. petiole attached to the lamina, with the blade narrowly peltate), flowers of both sexes with internally villous calyx (vs. flowers of both sexes with internally glabrous calyx), and pubescent stamens (vs. glabrous stamens).

Type: ___ BRAZIL. Goiás: Município de Cavalcante, Região da Chapada dos Veadeiros, cerca de 500 m antes do córrego Quebra Coco, na estrada para a Comunidade dos Kalungas, 13°36’27.5”S, 47°28’24.2”W, 1.066 m, 7 March 2013 (fl), M. J . Silva , R. C . Sodré , F. K. L. Silva , A. O . Souza & L. L. C . Antunes 4768 (holotype: UFG!) .

Subshrubs 11–40 cm tall, appearing from a xylopodium fusiform, monoecius, glabrous on vegetative parts; stem erect or dichotomously branched, cinereous, waxy; latex hyaline. Stipules 5–13.5 × 0.2–0.3 mm, linear, margins entire, glabrous, persistent. Leaves spirally alternate; petiole 2–6.1 cm long, angulate, yellowishgreen; blades 3.2–7.2 × 1.4–3 cm, ovate-lanceolate, ovate, or narrowly cordate, non-lobed, non-peltate, base cordate, apex acuminate, membranaceous, glabrous on both surfaces; venation camptodromousbrochidodromous, primary and secondary veins prominent on both surfaces, yellowish to slightly pinkish. Inflorescence racemose, in the axils of the dichotomous branches or at their apex, bisexual with one or two pistillate flowers and two or three staminate flowers. Staminate flower: bud 11–12 × 6–7 mm, ovoid to ellipsoid, yellowish; bracts (at the base of the pedicel) 6–7 × 0.3–0.4 mm, linear, persistent; bracteoles persistent; pedicel 4.9–5 mm long, cylindrical, glabrous, green, opaque; calyx 20–22 × 5.5–6.5 mm, slightly campanulate, yellowish, glabrous externally, villous internally, lobes lanceolate, apex acute, base truncate; stamens 10, in two whorls of five, filaments sparsely pubescent, anthers oblongoid, yellowish; disc 10-lobed, dark yellow. Pistillate flowers: buds 12–13 × 7–7.5 mm, ovoid, yellowish; bracts (at the base of the pedicel) 5.9–6 × 0.2–0.3 mm long, linear, glabrous, persistent; bracteoles caducous; pedicel 4–8 mm long, cylindrical, glabrous, greenish; sepals 12.9–14 × 2.9–3 mm, lanceolate to oval-laceolate, yellowish, glabrous externally, villous internally, apex acute to shortly acuminate, base truncate, margins involute; ovary 1.9–2.1 × 1.2–1.3 mm, oblongoid to subglobose, glabrous, green, disc patelliform, lobed, dark yellow; styles 3, slightly united at the base, free portion 3.5–3.6 mm with the apex multifid. Capsules 9–11 × 8–8.5 mm, widely oblongoid to subglobose, smooth, with septicidal and loculicidal dehiscence, green, opaque, slightly waxy. Seeds 5–5.1 × 3.9–4.1 mm, oblongoid, maculate, caruncle prominent, cream to yellowish.

Additional specimens examined (paratypes): — BRAZIL. Goiás: Cavalcante, estrada Minaçu– Cavalcante, passando pela basal Serra Branca , a cerca de 126 km do rio Tocantins, 13°35’35”S, 47°31’24”W, 10 November 2000 (fl), B. M. T . Walter et al. 4686 ( CEN, UFG); Comunidade Kalunga, caminho para a cachoeira Santa Bárbara, 13°33’44”S, 47°38’29”W, 26 February 2005 (fl, fr), J. F. B . Pastore & M . Aquino 1268 ( CEN, UFG); ibd., Engenho II, próximo ao Córrego Quebra Coco, 13°34’57”S, 47°28’21”W, 16 January 2010 (fl, fr), J. E. Q . Faria , L. Z. O . Campos , J. S . Santos & R. C . Martins 730 ( CEN, UB); ibd., antes da curva que dá acesso ao Córrego Quebra Coco, em direção à comunidade Kalunga, 13°36’27.5”S, 47°28’24.2”W, 1.066 m, 16 Feb 2013 (fl, fr), R. C . Sodré 541 ( UFG), 542 ( UFG), 543 ( UFG); ibd., 7 March 2013, (fl, fr), M. J . Silva , R. C . Sodré , F. K. L. Silva , A. O . Souza & L. L. C . Antunes 4760 ( UFG), 4761 ( UFG), 4762 ( UFG), 4763 ( UFG), 4764 ( UFG), 4765 ( UFG), 4766 ( UFG), 4767 ( UFG); ibd., 7 March 2013 (fr), F. K. L . Silva , M. J . Silva , R. C . Sodré , A. O. Souza & L. L. C . Antunes 23 ( UFG), 24 ( UFG), 25 ( UFG), 26 ( UFG), 27 ( UFG), 28 ( UFG) .

Distribution and ecology: —So far, known only from the surroundings of the Comunidade Kalunga, municipality of Cavalcante, in the northern extension of Chapada dos Veadeiros, state of Goiás, where it grows in grassland vegetation, from 1.050 to 1.120 m elevation, on rocky and acidic soils.

Conservation status: —According to the IUCN criteria ( IUCN 2010), the species can be recognized as Critically Endangered CR [B2 ab (ii)], because it occurs in small, isolated populations in the grassland around the municipality of Cavalcante, an area of occurrence smaller than 100 km 2 not protected by law and generally disturbed by human occupancy since it is a touristic destination.

Etymology: — The species epithet alludes to the Kalunga people, who descend from nineteenth-century slaves and live in communities named “quilombolas” in northern Goiás, the region where M. kalungae grows.

Phenology: — Flowering and fruiting specimens have been collected from January to March.

Discussion: — Manihot kalungae likely belongs to Manihot section Peltatae Pax , which includes, according to Rogers & Appan (1973), M. peltata Pohl (1827: 20) , M. populifolia Pax (1910: 93) , and M. reniformis Pohl (1827: 56) , all taxonomically poorly known species. This section can be differentiated from other Manihot sections mainly because it includes caulescent plants, usually subshrubs, with non-lobed or very shallowly lobed leaves, widely spaced on the stem, peltate or with basal attachment of the petiole, monoecious racemose inflorescences, and setaceous bracts with entire margins.

Manihot kalungae is similar to M. populifolia regarding habit and general leaf shape, but it can be easily distinguished from by its persistent stipules, basal attachment of the petiole, flowers of both sexes with the internally villous calyx, and pubescent stamens (versus caducous stipules, petiole attached to the lamina and the blade narrowly peltate flowers of both sexes with internally glabrous calyx, and glabrous stamens in M. populifolia ).

Also, M. kalungae occurs in the state of Goiás, Brazil, while M. populifolia was reported by Rogers & Appan (1973) from Sierra de Amambay in Paraguay. With the addition of this new species, Manihot sect. Peltatae now encompasses four species, which can be identified by the key below.

Figures

FIGURE 1. Manihot kalungae. A. Habit. B. Stipule. C. Adaxial leaf surface. D. Staminate flower with calyx split and opened. E. Stamen. F. Pistillate flower. G. Detail of the inner surface of the pistillate sepals showing the villous trichomes. H. Fruit. I. Seed, dorsal side. From M. J. Silva, R. C. Sodré, F. K. L. Silva, A. O. Souza & L. L. C. Antunes 4768 (UFG), drawn by Cristiano Gualberto.