Baccharis simplex G.Heiden, 2014

Heiden, Gustavo & Pirani, José Rubens, 2014, Two new species of Baccharis subgen. Baccharis (Asteraceae, Astereae) with single-flowered female capitula from the Serra do Cipó, Minas Gerais, Brazil, Phytotaxa 164 (2), pp. 141-148 : 144-147

Baccharis simplex G.Heiden , spec. nov. ( Figures 4 and 5 )

Type: — BRAZIL. Minas Gerais: Jaboticatubas, Serra do Cipó, APA Morro da Pedreira, Rodovia Belo Horizonte – Conceição do Mato Dentro (MG010), km 116, Alto do Palácio, topo das elevações com escarpas voltadas para o vale do Córrego Palácio , 19°15' S, 43°32' W, elevation 1250 m a.s.l., 17 February 2011, fl., fr., ♀, G. Heiden, J.R. Pirani, C.M. Siniscalchi & M.F. Devecchi 1611 (holotype SPF! ; isotypes BHCB! , JE! , RB! , Herbário da Embrapa Clima Temperado, Pelotas, RS, Brasil! ).

Shrubs 0.3–0.5 m tall, erect; strongly resinous; bark light brown. Leaves with petioles 1–2 mm long, leaf blade coriaceous, 6.8–11 mm long, 3–6.6 mm wide, strongly resinous, broadly elliptic to oblong, apex rounded to obtuse, base obtuse, margins with 1–4 smooth teeth on distal half of each side, venation pinnate, craspedodromous, with 3– 5 pairs of major lateral veins, midrib prominent on abaxial surface, glandular-punctate on both surfaces. Capitula solitary, in the leaf axis of the younger shoots. Male capitula with peduncles 1.2–2.5 mm long; capitula 2.5–2.7 mm long; florets 2–7; involucre 1.9–2.2 mm long, 1.2–2.7 mm in diam., cup-shaped; phyllaries 3-seriate, outermost phyllaries lanceolate, median ovate, innermost ovate-lanceolate, stramineous, margins entire, scarious, apices acute; clinanthium plane, glabrous; corolla 1.9–2.3 mm long, tube 1.1–1.3 mm long, throat 0.2–0.3 mm long, lobes 0.6–0.8 mm long; style 2.3–2.4 mm long, apex slightly cleft, distally dilated, ovary abortive, glabrous; pappus uniseriate, 2–2.3 mm long, bristles 14–18, apex broadened, short-protruding, erect terminal cell apices. Female capitula sessile, 3.5–4.1 mm long; involucre 3.5–4 mm long, 1–1.3 mm in diam., cylindrical, narrowed at distal end; phyllaries 3–4-seriate, stramineous, outer lanceolate, median ovate, innermost linear-lanceolate, margins entire, scarious, apices acute; clinanthium slightly convex, glabrous; florets 1; corolla 1.4–1.5 mm long, filiform, with 5 obtuse apical teeth; style 1.4–1.6 mm long., branches 0.2–0.3 mm long; cypselae 1.5–1.7 mm long, 0.55–0.6 mm in diam., brown, glabrous, oblong, slightly narrowed at bases, with 12–14 strong longitudinal ribs; pappus biseriate, 1.2–1.4 mm long, bristles 60–80, apically not broadened, not elongated at cypsela maturity, deciduous.

Distribution: —Known only from elevations between 1250–1400 m a.s.l. with two precise records at Alto do Palácio and in the private reserve of Brumas do Espinhaço ( Figure 3 ) within the Serra do Cipó range, a portion of the Espinhaço ridge, the latter extending from central Bahia to Southern Minas Gerais states ( Giulietti et al. 1997).

Habitat: — Baccharis simplex grows in areas of exposed fine quartzite sediments found at the very top of elevations amidst the rocky grasslands (campos rupestres) vegetation.

Phenology: —Fertile specimens, flowering and setting fruit, have been collected in February and July.

Conservation status: —Because of the limited extent of occurrence, known only for small populations recorded from two, maybe three localities, and the loss of quality of the campos rupestres ecosystem due to anthropogenic pressure ( Burman 1991, Giulietti et al. 1997), the new species is assessed as Endangered: EN B1ab(iii) ( IUCN 2011).

Etymology: —The specific epithet refers to the single-flowered female capitula and to the ordinary overall aspect of the plants, which share habit and leaf characters that are quite common to several other species of Baccharis subgen. Baccharis .

Additional specimens examined (paratypes): — BRAZIL. Minas Gerais: Jaboticatubas, Serra do Cipó, APA Morro da Pedreira, Rodovia Belo Horizonte – Conceição do Mato Dentro (MG010), km 116, Alto do Palácio, topo das elevações com escarpas voltadas para o vale do Córrego Palácio , 19°15' S, 43°32' W, 1250 m, 17 February 2011, fl., ♂, G. Heiden, J.R. Pirani, C.M. Siniscalchi & M.F. Devecchi 1610 ( BHCB, JE, RB, SPF, Herbário da Embrapa Clima Temperado, Pelotas, RS, Brasil!) . Santana do Riacho, RPPN Brumas do Espinhaço , 1414 m, 11 July 2012, fl., ♂, M.G.C. Fernandes, F.M. Fernandes & C.A. Ferreira Júnior 1570 ( BHZB, HUFU, SPF) ; Serra do Cipó , 1400 m, 11 May 1974, fl., ♂, G. Martinelli 315 ( RB) .

Taxonomic position and affinity: — Baccharis simplex belongs to Baccharis subgenus Baccharis based on style apex of male florets bearing sweeping hairs of unequal size, female florets with 5-dentate corolla apex and glabrous>8-costate cypsela with deciduous biseriate pappus. The new species is similar to the sympatric B. concinna Barroso (1976: 162) , also endemic to the Serra do Cipó. The two species possess leaves with dentate margins and axillary few-flowered male capitula and single-flowered female capitula, being distinguished by habit, leaf shape and female capitula length. While B. simplex is a small shrub (0.3–0.5 m tall) with oval to oblong leaves, obtuse base and rounded to obtuse apex with small teeth and shorter female capitula (3.5–4.1 mm long), floret (1.4–1.5 mm long) and cypsela (1.5–1.7 mm long), B. concinna is a taller shrub (0.5–1 m tall) with obovate to lanceolate leaves, attenuate base and rounded apex with coarse teeth and longer female capitula (4.5–5 mm long), floret (2–2.2 mm long) and cypsela (2–2.2 mm long).

Figures

FIGURE 3. Distribution of Baccharis obdeltata and B. simplex. A. Overview map of South America pinpointing the position of the Serra do Cipó in south-eastern Brazil. B. A highlight in south-eastern Brazil depicting the boundaries of Minas Gerais state and the position of Serra do Cipó. C. Three-dimensional map showing part of the Serra do Cipó range, plotting the known distribution of B. obdeltata (Brumas do Espinhaço and Serra da Lapinha) and B. simplex (Alto do Palácio and Brumas do Espinhaço).

FIGURE 4. Baccharis simplex. A. Fertile shoot. B. Leaf and male capitulum. C. Male capitulum. D. Phyllaries of male capitulum. E. Male floret. F. Female capitulum. G.Female floret. H. Corolla and style of female floret. I. Cypsela (pappus removed). A–E: Heiden et al. 1610 (SPF). F–I: Heiden et al. 1611 (SPF). Illustration by João Iganci.

FIGURE 5. Baccharis simplex. A. Habitat and habit. B. Flowering shoot of a male plant. C. Flowering shoot of a female plant. Photos by G. Heiden.