Baccharis scopulorum A.A.Schneid. & G.Heiden, 2011

Schneider, Angelo Alberto, Heiden, Gustavo & Boldrini, Ilsi Iob, 2011, Baccharis scopulorum, a new species of section Caulopterae (Asteraceae: Astereae) from rocky cliffs of southern Brazil, Phytotaxa 15, pp. 9-14 : 10-12

Baccharis scopulorum A.A.Schneid. & G.Heiden , sp. nov. ( Figures 1 and 3 )

Ad Baccharis sect. Caulopterae pertinens, B. altimontana similis , sed foliis basalibus evolutis vel sparsim in ramis (vs. foliis evolutis absentibus), ramis erectis (vs. erectus-patentibus), capituliis staminatis cum 60–135 flosculis (vs. 35– 63 flosculis), capituliis pistillatis cum 130–140 flosculis (vs. 34–42 flosculis) et cypselis 10–14–costatis (vs. 16–22– costatis) differt.

Type:— BRAZIL. Santa Catarina: Grão-Pará / Urubici, Serra do Corvo Branco , rodovia SC 439 , 28°03’36.5”S, 49°21’48,1”W, 1334 m, ♂ , fl, 19 October 2006, Schneider 1333 (holotype ICN) .

Subshrub, 25–40 cm tall; shoots erect or erect–patent, terminating in solitary or paired capitula born at the tip of the branches; stems 3-winged, wings 4–7 x 0.7–1.4 cm, laminate or slightly undulate, coriaceous, slightly resinous, light green, indumentum tufted. Basal leaves 1.5–4 x 1–3.4 cm, obovate to orbicular or spathulate, sessile to sub-sessile, subcoriaceous, 3(–5)-veined, the base attenuate, the margins entire, slightly revolute, the apex obtuse to rounded, mucronulate; stem leaves developed or bract-like. Capitula sessile, solitary or paired, born mostly at the tips of the branches. Staminate capitula 5.6–7 mm; florets 60–135; involucre 4–4.5 x 6–8 mm, campanulate; phyllaries in 4 or 5 series, the outermost phyllaries ovate, the median phyllaries oblong, the innermost phyllaries lanceolate, resinous and brightly coloured, the apex acute; corolla 2.7–4 mm, tube 2.2–3.2 mm, lobes 0.5–0.8 mm; style 4.0– 5.3 mm, the apex nearly fully cleft into two lanceolate branches, these slightly dilated towards their apex, ovary abortive, glabrous; pappus uniseriate, 4– 4.5 mm, bristles 16–18, apically broadened and scarcely barbellate. Pistillate capitula 7–8 mm; florets 130– 140; involucre 4.5–5 x 5–7 mm, campanulate to urceolate; phyllaries in 4 or 5 series, outermost phyllaries ovate, the median phyllaries oblong, innermost phyllaries lanceolate, resinous and brightly coloured, the apex acute; corolla 2–4 x 0.05–0.15 mm, filiform, ligulate with a dentate ligule, glabrous; style 3–4 mm; cypselae 1.3–2 x 0.3–0.4 mm, nearly cylindrical, 10–14–ribbed, pappilose, pappus uniseriate, 2.2–3 mm, bristles 16– 19, stramineous, persistent, basally fused.

Distribution:—Known only from elevations above 1400 m at Serra do Corvo Branco, part of the eastern edge of the Serra Geral plateau, which is the boundary between the municipalities of Grão-Pará and Urubici, at the state of Santa Catarina, southern Brazil ( Figure 2).

Phenology:—Flowering and fruiting specimens have been collected during October and November.

Habitat:—To date Baccharis scopulorum is known from a single site growing directly attached to bare rock at the ledges of outcrops and cliffs on steep slopes subject to constant fog and high humidity. These outcrops occur in the transitional zone of cloud forests and dense forests of the Atlantic Rainforest.

Conservation status:—The new species, according to IUCN Red list category ( IUCN 2010), is considered Endangered (EN subcriteria D1—very small or restricted population) as it grows in a highly specialized habitat and is known from a single population, found in an area difficult to access due the steep and slippery slopes. We can estimate the existence of about 150 individuals in the most accessible places.

Etymology:—The epithet means 'of the cliffs' referring to the habitat of the species on the cliffs of the Serra do Corvo Branco, part of the Serra Geral range.

Additional specimens examined (paratypes):— BRAZIL. Santa Catarina: Grão-Pará / Urubici, Serra do Corvo Branco , SC 439 , 28°03’36.5”S, 49°21’48,1”W, 1334 m, 13 November 1995, ♂, M. R . Ritter 892 ( ICN); 19 October 2006, ♀, A. A . Schneider 1326, 1347 ( ICN); ♂, A. A . Schneider 1331, 1332 ( ICN); 28 October 2008, ♀, J. R. V . Iganci 505 ( SPF); ♂, J. R. V . Iganci 506 ( HECT, SPF); 3 April 2010 , sterilis, G. Heiden , J. R. V . Iganci & T . Särkinen 1336 ( SPF) .

Current taxonomic studies on Brazilian Baccharis sect. Caulopterae recovered a species previously identified as a new record of B. opuntioides Mart. ex Baker for southern Brazil ( Schneider & Boldrini 2008). In the current work, this species is identified as an undescribed species on the basis of its distinctive morphology, geographical distribution and habitat preferences.

Baccharis scopulorum belongs to Baccharis sect. Caulopterae on the basis of its 3-winged stems, epaleaceous clinathia which are densely covered with bisseriate glandular hairs and the bristles of the female pappus which are basally fused into a ring. This species is morphologically most similar to B. altimontana Heiden, Baumgratz & Esteves (2009a: 140) and B. opuntioides .

We believe Baccharis scopulorum to be most closely related to B. altimontana based on its 3-winged stems, urceolate to campanulate involucra of the female capitula and the uniseriate pappus of the female florets; and to B. opuntioides based on its 3-winged stems, erect branches, and the uniseriate pappus of the female florets. Baccharis scopulorum may be distinguished from B. altimontana and B. opuntioides based on the characters listed in Table 1.

Figures

FIGURE 1. Baccharis scopulorum. A. Habit (Schneider 1333, ICN). B. Representative leaves (Schneider 1331, 1332, ICN). C. Staminate capitulum (Schneider 1333, ICN). D. Pistillate capitulum (Schneider 1326, ICN). E. Phyllaries of pistillate capitulum (Schneider 1326, ICN). F. Staminate floret (pappus removed) (Schneider 1333, ICN). G. Corolla and style of pistillate floret (Schneider 1326, ICN). H. Cypsela with pappus (Schneider 1326, ICN).

FIGURE 3. Baccharis scopulorum. A. Habitat on cliffs of bare rock outcrops. B. Habit. C. Staminate capitulum. D. Pistillate capitulum. E. Cypsela in SEM. C. Schneider 1333 (ICN). D–E. Schneider 1326 (ICN). Scale bars B. 5 cm. C–D. 1 mm. E. 200 µm.