Croton longibracteatus Mart., 2005

Barbosa, Bárbara Laís Ramos, Oliveira, Reyjane Patrícia, Mascarenhas, Ana Angélica Silva, Dórea, Marcos Da Costa, Martins, Fabiano Machado & Carneiro-Torres, Daniela Santos, 2018, Croton aemulus and C. graomogolensis (Euphorbiaceae): Two new species from Minas Gerais, Brazil, based on distinct lines of evidence and their relation to C. muscicapa and C. longibracteatus, Phytotaxa 365 (3), pp. 259-272 : 265-267

Croton longibracteatus Mart. -Gord. & de Luna (2005: 568). ( Fig. 1 , 4 A , 5 F–J )

Type:— BRAZIL. Bahia: 7–10 km de Seabra-Itaberaba oeste de Lençóis, 27 May 1980, R.M. Harley, G.L. Bromley, A.M. de Carvalho, J.M. Soares, J.L. Hage & E. B. dos Santos 22675 (holotype NY; isotypes CEPEC!, IPA) .

Description: —Shrubs, monoecious, erect, 1–3 m tall, foliage viscid, green-vinaceous, hirsute to pubescent, trichomes stellate-rotate, porrect, radii 6–8. Leaves simple, alternate, stipules lanceolate, glandular, 1.5–5.5 × 1–3 mm; petiole 7.5–43.5 mm long, hirsute, eglandular; blade ovate, 21–99 × 15.5–52 mm, apex acuminate, base cordate to subcordate, margin dentate, with one gland at the apex of each tooth, adaxial surface subglabrous, abaxial surface glabrous to pubescent, trichomes stellate; venation actinodromous. Inflorescences terminal, bisexual, 21–138 mm long, hirsute, with proximal pistillate flowers and distal staminate flowers, distributed continuously along the rachis; bracts lanceolate, staminate flower bracts 4–12 mm long, pistillate flower bracts 5–19 mm, fimbriate-glandular. Staminate flowers yellowish green, 6–11 mm long, pedicels 1–7 mm long; sepals 5, ovate, 3–6 × 1.5–3.5 mm, adaxial surface glabrous with trichomes only at the apex, abaxial surface glabrous; petals 5, ovate, 2–6 × 1–4 mm; stamens 11–12, 6–11.5 mm long. Pistillate flowers 9–17.5 mm long; pedicels 1–6 mm long; sepals 5, lanceolate, 9.5–18 × 1–3 mm, pilose, margin glandular, glands long-stipitate, reduplicate; petals absent; ovary globose, pubescent; styles 3, united at the base, multifid, with 6–13 terminal tips, glabrous. Capsules globose, 4–8 × 5–9 mm, pubescent; seeds globose, 4–6 × 3–7 mm, smooth, carunculate.

Morphological comments: — Croton longibracteatus is here confirmed as a distinct species from C. muscicapa ( Fig.5 A–E ), but we are proposing modifications to its original description made by Martínez-Gordillo & de Luna (2005) and geographic distribution, as noted below. The current morphological delimitation of this species includes the following: leaf blades with subglabrous adaxial surface, margins with one gland at the apex of each tooth; staminate flowers 6–11 mm long, stamens 11–12, 6–11.5 mm long, bracts 4–12 mm long; pistillate flowers 9–18 mm long, bracts 5–19 mm long, and sepals with long-stipitate glands.

Geographic distribution, habitat and conservation: —This species is exclusive to campo rupestre vegetation in Chapada Diamantina, Bahia, Brazil ( Fig. 1 ), from 780 to 1,021 m elevation ( Tab. 2). We do not consider this species threatened with extinction, according to IUCN (2012) criteria, because it occurs in five localities within Chapada Diamantina National Park, which is a protected area.

Specimens examined: — BRAZIL. Bahia: Andaraí, ca. 2 km S de Andaraí na estrada para Mucugê, 10 October 2008, L.P. de Queiroz et al. 13590 (HUEFS); estrada de chão de Mucugê para Igatú, 13º01’43.5”S, 41º21’38”W, 28 January 2015, B.L.R. Barbosa et al. 13 (HUEFS). Lençóis, BR 242, na beira da pista, do outro lado do Rio Mucugezinho, antes da placa do Orquidário, 12º27’52.3”S, 41º25’45.4”W, 29 January 2015, B.L.R. Barbosa et al. 14 (HUEFS); trilha para a Pedra Verde, 30 January 2015, B.L.R. Barbosa et al. 15 (HUEFS). Mucugê, em frente ao Cemitério Bizantino, 13º00’40.6”S, 41º22’59.8”W, 26 January 2015, B.L.R. Barbosa et al. 11 (HUEFS); arredores da cidade, trilha para o Vale do Medonho, 13º05’21”S, 41º22’41”W, 27 January 2015, B.L.R. Barbosa et al. 12 (HUEFS). Palmeiras, área em frente ao Rio Mucugezinho, 17 November 2006, S.P.S. Neves 149 (HUEFS).

Figures

FIGURE 1. Map showing known distribution of the four species.

FIGURE 4. Morphological comparison of species. Leaf margin, stipules, sepals, and bracts. A. C. longibracteatus (Barbosa et al. 11, HUEFS). B. C. aemulus (Barbosa et al. 19, HUEFS). C. C. muscicapa (Barbosa et al. 4, HUEFS). D. C. graomogolensis (Barbosa et al. 17, HUEFS). Scale bars = 1 mm.

FIGURE 5. C. muscicapa (Barbosa et al. 4, HUEFS) and C. longibracteatus (Barbosa et al. 11, HUEFS). A–E. C. muscicapa: A. Habit; B. Glabrous leaf; C. Glandular stipules, resembling a brunch of grapes; D. Staminate flower; E. Pistillate flower; F–J. C. longibracteatus. F. Habit; G. Leaf with details of the subglabrous adaxial surface and pubescent abaxial surface; H. Glandular, lanceolate stipules; I. Staminate flower; J. Pistillate flowers with one sepal removed. Drawing by Lucas Menezes.