Croton muscicapa Müller Argoviensis (1873: 199)

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 : 268

Croton muscicapa Müller Argoviensis (1873: 199) . ( Fig. 1 , 4 C , 5 A–E )

Type:— BRAZIL. Bahia: in Serra do Gado Bravo prope Villa Nova da Rainha, April, C.F.P. von Martius Obs. 2260 (holotype M!).

Description: —Shrubs, monoecious, erect, 1–2 m tall, foliage viscid, green-vinaceous, glabrous to pilose, trichomes stellate-rotate, porrect, radii 6–8. Leaves simple, alternate; stipules glandular, resembling a bunch of grapes, 0.5–2 mm; petiole 10–44 mm long, glabrous to hirsute, eglandular; blade ovate, 16–67 × 14.5–51.5 mm, apex acute, base cordate, margin serrate, with 1–3 sessile glands at the apex of each tooth, glabrous to pubescent on both surfaces, trichomes stellate; venation actinodromous. Inflorescences terminal, bisexual, 14–109 mm long, glabrous to pilose, with proximal pistillate flowers and distal staminate flowers, distributed continuously along the rachis; bracts lanceolate, staminate flower bracts 1–3.5 mm long, pistillate flower bracts 1–6 mm long, fimbriate-glandular. Staminate flowers 4–7 mm long; pedicel 2–6 mm long; sepals 5, ovate, 3–5 × 1–3 mm, adaxial surface glabrous with trichomes at the apex, abaxial surface pubescent; petals 5, ovate, 3–5.5 × 2–4 mm; stamens 11–12, 3.5–6 mm long. Pistillate flowers 6–10 mm long; pedicel 3–12 mm long; sepals 5, 4.5–10.5 × 1–2.5 mm, lanceolate, glabrous to pubescent, margin with short-stipitate glands, not reduplicate; petals absent; ovary globose, glabrous to pubescent; styles 3, united at the base, with 9–15 terminal tips, glabrous. Capsules globose, 5–7 × 5–7 mm, glabrous to pubescent; seeds globose, 3–5 × 2–4.5, smooth, carunculate.

Morphological comments: — Croton muscicapa is mainly characterized by the presence of the following: leaf blades with a glabrous to pubescent adaxial surface, margins with one to three glands at the apex of each tooth; staminate flowers 4–7 mm long, stamens 11–12; pistillate flowers 6–10 mm long, bracts 1–6 mm long, and sepals with short-stipitate glands. Besides the morphological differences regarding C. graomogolensis mentioned above, C. muscicapa is distinct from C. longibracteatus based on the width of the middle of the leaf blade, width of the bracts (¼ from the end), and longer pedicel of the pistillate flower of C. muscicapa . They also have distinct genetic pools, reinforcing their delimitations.

Geographic distribution, habitat and conservation: —This species occurs in seasonal forest and caatinga vegetation in Chapada Diamantina, Bahia, Brazil ( Fig. 1 ), from 593 to 740 m elevation ( Tab 2). We do not consider this species threatened with extinction, according to IUCN (2012) criteria, due its occurrence in eight localities within Chapada Diamantina National Park, which is a protected area.

Specimens examined: — BRAZIL. Bahia: Jacobina, estrada para a antiga Companhia Força Luz, 11º10’775”S, 40º29’911”W, 16 November 2014, B.L.R. Barbosa et al. 1 (HUEFS); Povoado de Itaitú, Cachoeira Véu de Noiva, 11º19’944”S, 40º30’198”W, 16 November 2016, B.L.R. Barbosa et al. 4 (HUEFS). Miguel Calmon, 14 January 1991, A.M. Miranda & F. Esteves 331 (HUEFS). Palmeiras, Serra Negra, 27 April 2015, B.L.R. Barbosa et al. 16 (HUEFS). Pindobaçú, Trilha para a Serra da Fumaça, 10º40’080”S, 40º21’724”W, 17 November 2014, B.L.R. Barbosa et al. 8 (HUEFS). Rui Barbosa , 28 May 2005, T.A.B. Costa 27 (HUEFS). Tapiramutá, estrada de chão Bonito-Tapiramutá 25 km de Bonito, 27 June 2005, D.S. Carneiro-Torres et al. 585 (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.