A new acicular-leaved species of Sauvagesia (Ochnaceae) from Chapada Diamantina, Bahia, Brazil DOMINGOS BENÍCIO OLIVEIRA SILVA CARDOSO
AND
ABEL AUGUSTO CONCEIÇÃO
Programa de Pós-Graduação em Botânica, Universidade Estadual de Feira de Santana, Km 03, BR 116, Campus, Feira de Santana, 44031-460 Bahia, Brazil; e-mail:
[email protected]
Abstract. A new species of Sauvagesia is described and illustrated under the name Sauvagesia paniculata. This new species is morphologically similar to the acicularleaved species of the subsect. Vellozianae. However, S. paniculata can be clearly differentiated from the other acicular-leaved species by the paniculate inflorescence. Other diagnostic characters of S. paniculata include the shorter pedicel and longer leaves. This new species seems to be narrowly endemic to the “campo rupestre” vegetation in the Esbarrancado mountain range of Mucugê, in the Chapada Diamantina, Bahia, Brazil. Key Words: Bahia, campo rupestre vegetation, Chapada Diamantina, Ochnaceae, Sauvagesia. Resumo. Uma nova espécie de Sauvagesia é descrita e ilustrada sob o nome Sauvagesia paniculata. Esta nova espécie é morfologicamente similar às espécies da subsect. Vellozianae que apresentam folhas aciculares. No entanto, S. paniculata é claramente diferenciada das demais espécies de folhas aciculares por possuir inflorescência paniculada. Outros caracteres diagnósticos de S. paniculata são o pedicelo mais curto e as folhas maiores. Esta nova espécie parece ser endêmica restrita da vegetação de campo rupestre da Serra do Esbarrancado em Mucugê, Chapada Diamantina, Bahia, Brasil.
Sauvagesia L. (Ochnaceae) contains about 35 species (Sastre, 2004), most of which are found in Brazil, and reaches its highest diversity and endemism in the campo rupestre vegetation of Minas Gerais and Bahia States (Sastre, 1997; Zappi & Lucas, 2002). The genus is diagnosed by the combination of actinomorphic flowers with pink or white petals, five stamens, and one or two staminodal whorls external to the stamens. The structure of the staminodal whorls was considered by Sastre (1981) as important to distinguish the two subsections within Sauvagesia sect. Sauvagesia Sastre. Accordingly, Sauvagesia subsect. Sauvagesia has free staminodes, while Sauvagesia subsect. Vellozianae Sastre is characterized by fused stam-
inodes resembling a corona-like structure that envelops the stamens and the pistil. The remarkable richness of Sauvagesia in the Chapada Diamantina is reflected in descriptions of new taxa during only the last four years. Zappi & Lucas (2002) described Sauvagesia nitida Zappi & E. Lucas from the vicinity of Catolés. More recently, Harley et al. (2005) described two species with acicular leaves from the Gobira mountain, Mucugê: Sauvagesia oliveirae Harley & Giulietti and Sauvagesia ribeiroi Harley & Giulietti. Almost at the same time, the present authors collected another acicular-leaved species of Sauvagesia in Esbarrancado mountain, also in Mucugê, that is clearly different from those previously known from the Chapada Diaman-
Brittonia, 60(4), 2008, pp. 305–309 © 2008, by The New York Botanical Garden Press, Bronx, NY 10458-5126 U.S.A.
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tina. This new species is herein described and illustrated. Sauvagesia paniculata D. Cardoso & A. A. Conc., sp. nov. Type: Brazil. Bahia: Mucugê, Chapada Diamantina, Serra do Esbarrancado, 12°43′51″S, 41°30′33″W, 1500 m, 15 Sep 2006 (fl, fr), A. A. Conceição & D. Cardoso 1835 (holotype: HUEFS; isotypes: CEPEC, K, MBM, NY, P, RB). (Fig. 1) Sauvagesia paniculata, inter species sect. Sauvagesiae subsect. Vellozianarum, habitu ericoideo et foliis acicularibus ad S. semicylindrifoliam, S. ribeiroi et S. oliveirae accedens, sed ab eis inflorescentia paniculata, foliis relative majoribus, 18–26 mm longis (non 10–12[–16] mm ut in S. semicylindrifolia, [8–]12–19 mm in S. ribeiroi et 4–4.5 mm in S. oliveirae), pedicello breviore, 3–5 mm longo (non 8–12 mm ut in S. semicylindrifolia, 10–16 mm in S. ribeiroi et ca. 8 mm in S. oliveirae), corolla campanulata (non petalis patentibus ut in S. semicylindrifolia et in S. ribeiroi) differt.
Shrub up to 2 m high, erect, stems leafless below, glabrous, terete, well-branched to the apex, sometimes sprouting from lateral buds at the base after burning, branches straight and slightly rugose, with conspicuous stipular tissue. Stipules ca. 3 mm long, the blade inconspicuous, appressed to stem, narrowly lanceolate, margins and apex broadly fimbriate. Leaves acicular, imbricate, slightly erect, densely clustered at apex of branches; leaf lamina 18–26 ×ca. 0.5 mm, rigid, greenvinaceous, with apex acute and base narrow, margin entire, eglandular; petiole 1–1.5 mm long. Panicle to 4–9 cm long, well-branched, terminal, slightly horizontal, about 10–30flowered; bracts ca. 2 mm long, lanceolate, fimbriate at the base, dark-vinaceous, glossy; pedicel ca. 3–5 mm long, deeply vinaceous. Flowers 5–7×10–12 mm, nodding, appearing slightly tubular-campanulate due to the erect petals; sepals 5, ca. 2×1 mm, ovate-elliptic, apex apiculate, eglandular, dark-vinaceous, glossy; petals 5, 5.5–7×3.5–4.5 mm, contorted, erect, obovate, pinkish, apex acute; staminodes 5 in a single series, fused into a conical tube covering the stamens, short, 2.8– 3.5 mm long, deep pink, with apex 5-lobed; stamens 5, free, anthers ca. 2 mm long, basifixed with short, thick filaments, oblong, apiculate, tetrasporangiate, dithecal, dehiscing by longitudinal slits; style ca. 2.5 mm long, subulate,
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projecting ca. 0.8 mm beyond staminodal tube, stigma simple; ovary ca. 1×0.8 mm, 3-lobed, 3-carpelled, uniloculate, ovoid, glabrous, placentation parietal, 10(–15) ovules per carpel. Fruit a septicidal capsule, up to 0.7 mm long, erect, with persistent sepals, staminodes and stamens, 3-valved, ovoid-apiculate. Seeds ca. 1 mm long, mid brown, obovoid, punctulatefoveolate. Etymology.—The specific epithet refers to the paniculate inflorescences, which have not been found in other acicular-leaved species of Sauvagesia. Ecology and Distribution.—Sauvagesia paniculata seems to be a narrow endemic of Mucugê, in the Chapada Diamantina, Bahia, Brazil. It is only known from the summit of Esbarrancado mountain at 1500 m. In this area, the predominant vegetation is campo rupestre, which is characterized by a mosaic of different physiognomies occurring side by side, composed mainly of a herbaceousshrubby layer, on a rocky quartzite-sandstone substrate and on sandy soils (Conceição, 2006). The new species was encountered in both flower and fruit in April and September. Conservation.—The three recently described species of Sauvagesia (Zappi & Lucas, 2002; Harley et al., 2005), as well as S. paniculata and the many endemics of the campos rupestres (Zappi et al., 2003), are critically threatened because of their restricted distribution (following the criteria B-1-a, b of IUCN 2001). This also reinforces the conservation effort that should be devoted to the campo rupestre vegetation.
Additional specimens examined. BRAZIL. BAHIA: Mucugê, Chapada Diamantina, Serra do Esbarrancado, 12 43’51’’S, 41 30’33’’W, 16 Apr 2005 (fl, fr), A. A. Conceição et al. 1270 (HUEFS, MO, SP).
Like the other acicular-leaved species, Sauvagesia paniculata belongs to Sauvagesia subsect. Vellozianae due to the presence of fused staminodes. However, this new species can be easily differentiated from other acicularleaved species by the paniculate inflorescence, as well as the shorter pedicel (3–5 mm long in S. paniculata, 8–12 mm long in S. semicylindrifolia Sastre, 10–16 mm long in S.
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FIG. 1. Sauvagesia paniculata. A. Habit. B. Stipule. C. Leaf. D. Flower. E. Sepal. F. Petal. G. Internal staminodal whorl with style protruding. H. Internal staminodal whorl dissected to reveal stamens and the 5-lobed apex. I. Gynoecium. J, K. Stamen, dorsal view (J) and ventral view (K). L. Fruit with persistent sepals. (From the holotype.)
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(8–)12–19 present along margin, reddish shallowly crenate
