Baccharis obdeltata G. Heiden 2014, spec. nov.
Creators: name: Heiden, Gustavo
name: Pirani, José Rubens
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Asterales
Asteraceae
Baccharis
Baccharis obdeltata

description: Baccharis obdeltata G.Heiden, spec. nov. (Figures 1 and 2)
Type: — BRAZIL. Minas Gerais: Santana do Riacho, Serra do Cipó, Lapinha da Serra, trilha para o Pico do Breu, trilha secundária adjacente à encosta, 19°6'27" S, 43°40'20" W, elevation 1281 m a.s.l., 16 June 2010, fl., fr., ♀, G. Heiden, L.M. Borges, C.M. Siniscalchi & G. Müller 1385 (holotype SPF!; isotypes JE!, K!, RB!, Herbário da Embrapa Clima Temperado, Pelotas, RS, Brasil!).
Shrubs 0.3–0.7 m tall, erect, and strongly resinous; bark light brown. Leaves with petioles 1.2–2 mm long, leaf blade coriaceous, 4.2–10 mm long, 3.5–8 mm wide, strongly resinous, obdeltate, apex 3(–5)-dentate, base cuneate, margin entire or rarely with 2 teeth, venation pinnate, craspedodromous, with 1–2 pairs of major lateral veins, midrib prominent on abaxial surface, glandular-punctate on both surfaces. Capitula solitary, in leaf axils of younger shoots. Male capitula sessile, 2.6–2.9 mm long; florets 5–7; involucre 2.2–2.5 mm long, 1–1.7 mm in diam., campanulate; phyllaries 3-seriate, outermost phyllaries ovate, median narrow elliptic, innermost lanceolate, stramineous, margins slightly dentate, scarious, apices acute; clinanthium flat, glabrous; corolla 1.4–1.6 mm long, tube 0.9–1.1 mm long, throat 0.1–0.2 mm long, lobes 0.4–0.5 mm long; style 1.4–1.7 mm long, apex slightly cleft, distally dilated; ovary abortive, glabrous; pappus uniseriate, 1–1.4 mm long, bristles 14–16, apically broadened, short-protruding, erect terminal cell ends. Female capitula sessile, 3.1–3.3 mm long; involucre 3.1–3.4 mm long, 0.8–1 mm in diam., cylindrical, narrowed at distal end; phyllaries 3–4 series, stramineous, outer and median ovate, innermost linear-lanceolate, margins slightly dentate, scarious, apices acute; clinanthium slightly convex, glabrous; florets 1; corolla 0.6–0.85 mm long, filiform, with 5 obtuse apical teeth; style 0.85–0.95 mm long, branches 0.2– 0.25 mm long; cypselae 1.1–1.4 mm long, 0.3–0.4 mm in diam., brown, glabrous, oblong, slightly narrowed at bases, with 12–14 strong longitudinal ribs, pappus biseriate, 0.65–0.8 mm long, bristles 40–60, apically not broadened, not elongated at cypsela maturity, deciduous.
Distribution: —Known only from elevations between 1100–1400 m a.s.l. along the trail from Lapinha da Serra to Pico do Breu and in the private reserve of Brumas do Espinhaço (Figure 3) within the Serra do Cipó range, a portion of the Cadeia do Espinhaço, the latter extending from central Bahia to Southern Minas Gerais states (Giulietti et al. 1997).
Habitat: — Baccharis obdeltata forms dense populations along steep quartz outcrops in the rocky grasslands (campos rupestres) vegetation.
Phenology: —Fertile specimens, flowering and setting fruit, have been collected between May and June.
Conservation status: —Because of the limited extent of occurrence, known populations recorded from only three locations, and the increasing loss of quality of the campos rupestres ecosystem due to anthropogenic pressure (Burman 1991, Giulietti et al. 1997), the new species is assessed as Vulnerable: VU B1ab(iii) (IUCN 2011).
Etymology: —The specific epithet refers to the unusual obdeltate leaf shape.
Additional specimens examined (paratypes): — BRAZIL. Minas Gerais: Santana do Riacho, RPPN Brumas do Espinhaço, Brumoso, 1414 m, 12 July 2012, fl., ♂, M.G.C. Fernandes, F.M. Fernandes & C.A. Ferreira Júnior 1648 (BHZB, SPF); Serra do Cipó, Lapinha da Serra, trilha para o Pico do Breu, trilha secundária adjacente à encosta, 19°6'27" S, 43°40'20" W, 1281 m, 16 June 2010, fl., ♂, G. Heiden, L.M. Borges, C.M. Siniscalchi & G. Müller 1386 (BHCB, RB, SPF); subida para o falso Morro do Breu, subida em zigue-zague no primeiro trecho da trilha, 19°6'58.8" S, 43°40'10.7" W, 1110 m, 23 May 2011, fl., fr., ♀, C.M. Siniscalchi, C.R.M. Siniscalchi & R. Siniscalchi 225 (BHCB, RB, SPF); fl. ♂, C.M. Siniscalchi, C.R.M. Siniscalchi & R. Siniscalchi 226 (BHCB, RB, SPF); vertente na encosta da montanha, 19°6'29.9" S, 43°40'12.8" W, 1217 m, fl., fr., ♀, C.M. Siniscalchi, C.R.M. Siniscalchi & R. Siniscalchi 227 (JE, SPF); ♂, C.M. Siniscalchi, C.R.M. Siniscalchi & R. Siniscalchi 228 (JE, SPF); 19°6'26.1" S, 43°40'16.1" W, 1256 m, ♀ C.M. Siniscalchi, C.R.M. Siniscalchi & R. Siniscalchi 231 (K, NY, SPF); ♂, C.M. Siniscalchi, C.R.M. Siniscalchi & R. Siniscalchi 232 (K, NY, SPF).
Taxonomic position and affinity: — Baccharis obdeltata belongs to subgenus Baccharis on the basis of the style apex of its male florets bearing sweeping hairs of unequal size, female florets with 5-dentate corolla apex and glabrous>8-costate cypselae with deciduous biseriate pappus. The new species superficially resembles the allopatric B. truncata Gardner (1848: 82) occurring in the Espinhaço range from the northerly Chapada Diamantina south to the Serra do Ouro Branco range in ironstone vegetation (canga) but not hitherto recorded from the Serra do Cipó. Both species are characterized by the obdeltate leaves with cuneate basis. However, B. obdeltata can be distinguished by the smaller leaves (4.2–10 mm long and 3.5–8 mm wide) with 3(–5)-dentate apex, sessile male capitula bearing fewer florets (5–7) and single-flowered sessile female capitula, while B. truncata has larger leaves (1–2 cm long and 0.8–1 cm wide) with truncate apex, pedunculate male capitula bearing more florets (10–16) and pedunculate female capitula bearing 3–7 florets.
description: Published as part of 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, pp. 141-148 in Phytotaxa 164 (2) on page 142, DOI: 10.11646/phytotaxa.164.2.8, http://zenodo.org/record/5132678