Introduction

Dyckia Schultes & Schultes f., with 162 accepted species (Butcher & Gouda cont. upd.), is the second largest genus in Bromeliaceae subfamily Pitcairnioideae and the one with greatest diversity in Brazil, where approximately 80% of the species occur (Forzza, 2001). The members of this genus have an exclusively South American distribution, with diversity centers in southern Brazil within the Cerrado and Campos Rupestres ecosystems (Forzza, 2001). According to a phylogenetic analysis based on morphological characters, the genus Dyckia is considered monophyletic, which is supported by four synapomorphies: the lateral inflorescence, the peduncle bracts foliaceous and different in shape when compared to the leaves, the presence of nectaries on the sepals, and the petal-staminal tube (Forzza, 2001; 2005).

Dyckia is known from Argentina, Bolivia, Brazil, Paraguay and Uruguay. In Brazil, it occurs from sea level to elevations over 1000 m, usually in sun-exposed niches of the Atlantic Forest, Restinga, Caatinga, Campos Rupestres and Cerrado vegetation. Dyckia species are usually xeromorphic terrestrials growing in well-drained soils, or saxicolous on diverse rock outcrops (i.e., granitic, quartzitic, sandstone, or iron-rich "canga"), in dry or sometimes humid habits. (Leme et al., 2012)

The iron-rich "canga" is a geological typology of rock outcrops featuring compact, hard substrates with thin, nutrient-poor soils of high acidity and low water-holding capacity (Giulietti et al., 1997). Plants living in these ironstone outcrops are in general subjected to stressful environmental factors like high UV incidence, high daily temperature amplitude, winds, low relative air humidity (Jacobi et al., 2007), besides the high levels of heavy metals (Porto & Silva, 1989; Teixeira & Lemos-Filho, 2002; Vincent, 2004). In Bromeliaceae, some Dyckia species are reported as metallophytes in cangas, like Dyckia inflexifolia Guarconi & M.A. Sartori (Guarconi et al., 2012) in Minas Gerais state, D. cangaphyla P. Braun, Esteves & Scharf (Braun et al., 2010), in the state of Goias, Central Brazil, and D. duckei L. B. Sm. (Leme & Marigo, 1993) in the Serra dos Carajas, Para state, northern Brazil.

The new species described below are examples of new discoveries from surveys in the underexplored outcrops of iron-rich "canga" in Minas Gerais state.

Taxonomy

Dyckia conceicionensis O.B.C. Ribeiro & Leme, sp. nov. (Figs. 1-5, 6 A-F)

This new species is closely related to Dyckia brachyphylla L.B. Sm., differing by the longer leaf blades (9-10 cm vs. ca. 7 cm long), with longer spines along the margins (2.5-3 mm vs. ca. 1.5 mm long), longer inflorescence (18-20 cm vs. ca. 7 cm long), longer sepals (6-7 vs. ca. 4 mm long), longer (10-11 mm vs. ca. 8 mm long), and broadly spathulate petals (vs. elliptic).

Type: BRAZIL. Minas Gerais: Conceicao do Mato Dentro, Serra da Ferrugem, campo de canga couracada on the road to Pico do Soldado, 1027 m elevation, 19[degrees] 00' 21.8" S, 43[degrees] 23' 55.7" W, 5 September 2010, O.B.C. Ribeiro 267(holotype BHCB!).

Plants rupicolous or saxicolous on iron-rich outcrops, flowering 50-55 cm high. Leaves 20-21 in number, coriaceous; sheaths 1.7-1.9 x 2-2.2 cm, whitish, glabrous and lustrous on the both...