Baccharis umbellata G.Heiden & Ribas, 2012

Heiden, Gustavo & Ribas, Osmar Dos Santos, 2012, Baccharis umbellata (Asteraceae, Astereae): a new species endemic to the highest summits of Paraná, Southern Brazil, Phytotaxa 49 (1), pp. 23-28 : 24-27

Baccharis umbellata G.Heiden & Ribas , sp. nov. ( Figs. 1 and 2 )

Differs from Baccharis platypoda DC. in its pedunculate capitula arranged in monomorphic umbel-like capitulescences (versus densely aggregated capitula arranged in dimorphic glomerule-like capitulescences of pedunculate or sessile secondary capitula).

Type:— BRAZIL. Paraná: Antonina, Serra Ibitiraquire, Pico Paraná, 1922 m , fl, ♂, 20 December 1977. Subarbusto 40 cm, capítulo creme. Matinha nebular do cume do morro. O. S. Ribas & V. A. O. Dittrich 2183 (holotype MBM!; isotype US!) .

Subshrubs or shrubs 0.3–1 m tall, erect; shoots terminating in a capitulescence, strongly resinous; bark light brown to stramineous. Leaves with petioles 2.3–4.5 mm long, leaf blade coriaceous, 1.5–3.4 cm long, 0.4–2 cm wide, oblong to obovate, apex rounded to obtuse or truncate, base cuneate, margins with 5–12 pairs of smooth to coarse teeth distally, strongly resinous; venation pinnate, semi–craspedodromous, with 6–16 pairs of major lateral veins, midrib prominent on both surfaces; both surfaces with tufts of flagellate hairs and biseriate glandular hairs appearing as small resinous dots. Capitulescences of 4–8 capitula, terminal, umbellike, 1.4–2 cm long, 1.6–4.4 cm wide. Capitula pedunculate; peduncles 3.4–9.5 mm long. Male capitula 6.9– 8.8 mm long; florets 48–60; involucre 6.5–7.5 mm long, 4.5–7.7 mm wide, oblong to campanulate; clinanthium (receptacle) flat, glabrous; phyllaries in 4–6 series, pale yellow with a slightly darker subapical region, outer phyllaries ovate, median oblong, innermost lanceolate, margin dentate, scarious, apex acute; corolla 4.7–5.4 mm long, tube 3.4–4 mm long, throat 0.3–0.5 mm, lobes 0.7–1.2 mm long; anthers including apical appendages 1–1.6 mm long; style 4.9–6 mm long, apex nearly fully cleft into lanceolate branches with sweeping hairs of unequal size, slightly dilated towards apex; ovary abortive, puberulous with biseriate glandular hairs; pappus uniseriate, 4.5–5 mm long, bristles 16–20, with apically broadened, short-protruding, erect terminal cell apices. Female capitula 6.5–8 mm long; florets 10–20; involucre 5.8–7.1 mm long, 3.8–7.9 mm wide, cylindrical to campanulate, narrowed distally; clinanthium (receptacle) slightly convex, glabrous; phyllaries in 5–7 series, pale yellow with a slightly darker subapical region, outer and median oblong, innermost lanceolate to linear-lanceolate, margins dentate, scarious, apex acute; corolla 3–4.2 mm long, filiform, with 5 obtuse apical teeth; style 3.8–6.2 mm long, branches 0.6–0.9 mm long; cypselae 1.9–2.2 mm long, 0.79–1.1 mm wide, brown, glabrous, oblong, slightly narrowed at bases, with 12–16 strong longitudinal ribs; pappus biseriate, 4.5–5.2 mm long, bristles 40–60, apically not broadened, not elongated at cypsela maturity, deciduous.

Distribution:—Only known from elevations between 1600–1922 m a.s.l. on the summits of the peaks Camapuã, Paraná, and Tucum along the Serra do Ibitiraquire, which is a portion of the southern range of the Serra do Mar and the natural boundary between the municipalities of Antonina and Campina Grande do Sul, in the east of Paraná State, southern Brazil ( Figure 3 ).

Habitat:— Baccharis umbellata forms sparse populations along the edge of cloud forests thickets, amongst grasslands, or in rock outcrops within the High Altitude Tropical Grassland biome ( Iganci et al. 2011). These environments occur in the transitional zone of ombrophilous dense forests and high altitude grasslands of the Atlantic Rainforest Domain.

Phenology:—Fertile specimens have been collected all year round.

Conservation status: —Because of the limited area of occupancy, small and sparse populations recorded for only three locations, and loss of quality of the high altitude grasslands environment due anthropogenic pressure, the new species is assessed as Endangered: EN B 1ab(iii) ( IUCN 2011).

Etymology: —The specific epithet refers to the pedunculate heads arranged in terminal umbel-like capitulescences.

Additional specimens examined (paratypes):– BRAZIL. Paraná: Antonina, Serra do Mar, Serra Ibitiraquire, Pico Paraná, rampa de pouso da torre, 1800 m, 2 May 1971, fl., fr., ♀, N . Imaguire 503 ( MBM, PACA); subida ao Pico Paraná, 1920 m, 17 August 1996, fl., ♂, O. S . Ribas , J. M . Silva & E . Barbosa 1469 ( MBM). Campina Grande do Sul, Serra Ibitiraquire, Pico Camapuã , 3 February 2000, fl., ♂, O. S . Ribas , J . Cordeiro & E . Barbosa 3062 ( CTES, MBM); 28 November 2000, fr., ♀, F . Silveira 1 ( UPCB); 1600 m, 5 November 2011, fl., ♂, G . Felitto , B. K . Canestraro , E . D. Lozano & E . Curcio 200 ( MBM); 1600 m, 5 November 2011, fl., ♀, E . D. Lozano , B. K . Canestraro , G . Felitto & E . Curcio 774 ( MBM); Serra dos Órgãos, Morro Tucum, 19 November 1999, fl., ♂, J . Cordeiro , J. M . Cruz & L. A . Ferreira 1646 ( MBM); 22 September 2006, fl., ♂, J. M . Silva , E . Barbosa & F . Marinero 5077 ( MBM) .

Baccharis umbellata belongs to subgenus Baccharis because the style apex of male florets bears sweeping hairs of unequal size, the female florets have an apically 5-dentate corolla apex and because of the glabrous and>8-ribbed cypselae with deciduous biseriate pappus. The new species seems to be closely related to the allopatric species B. platypoda De Candolle (1836: 409) , which mainly inhabits mountain summits across western ( Bolivia and Peru) and eastern South America (Brazilian States of Bahia, Espírito Santo, Minas Gerais, Rio de Janeiro, and São Paulo), sharing the same leaf shape and texture, margin dentition and pattern of venation, however being easily differentiated by the pedunculate capitula arranged in umbel-like capitulescences (vs. sessile capitula forming densely congested capitulescences). Apart from the arrangement of capitula, B. umbellata can be distinguished from B. platypoda by its height (0.3–1 m vs. 1–3.5 m tall), smaller leaf blades (1.51–3.41 × 0.43–2 cm vs. 4–15 × 2–6 cm), dentate (vs. long-fimbriate) phyllary margins, more florets per male (48–60 vs. 10–30) and female capitulum (10–20 vs. 8–10) and wider male involucres (4.5–7.7 mm vs. 2.5–4.5 mm).

The section Agglomeratae Giuliano (2005: 535) was mainly circumscribed on the basis of the presence of dimorphic capitulescences in male (axillary pedunculate glomerules of sessile capitula or pedunculate secondary capitula) and female plants (terminal sessile globose capitulescence) and comprises B. platypoda DC. (eastern Brazilian populations) and B. condensata Rusby (1920: 148 ; Bolivian and Peruvian populations of B. platypoda , fide Müller 2006: 132). Despite the absence of dimorphic congested capitulescences in B. umbellata , which is characterized by the presence of umbel-like capitulescences of lax capitula in both male and female plants, its characteristics of habit, leaves and characters of florets and cypselae shows the new species’ unequivocal relationship to B. platypoda , supporting its inclusion in section Agglomeratae .

Figures

FIGURE 1. Baccharis umbellata. A. Fertile shoot. B. Capitulescence. C. Adaxial view of a leaf. D. Male capitulum. E. Phyllaries of male capitulum (outer to inner). F. Male floret. G. Female capitulum. H. Female floret. I. Corolla and style of female floret. J. Cypsela (pappus removed). A–F: Ribas & Dittrich 2183 (MBM). G–J: Imaguire 503 (PACA). Illustration by João Iganci.

FIGURE 2. Flowering shoot of a male specimen of Baccharis umbellata (Felitto et al. 200). Photo by B.C. Canestraro.

FIGURE 3. Distribution of Baccharis umbellata: A. Overview map of South America highlighting the position of Paraná State in southern Brazil and the Serra do Ibitiraquire in eastern Paraná. B. Three-dimensional map of the Serra do Ibitiraquire plotting the peaks of Camapuã, Tucum and Paraná, where the new species is recorded from.