Baccharis ser. Canescentes (Giuliano) G.Heiden, 2016

Heiden, Gustavo & Pirani, José Rubens, 2016, Taxonomy of Baccharis subgen. Tarchonanthoides (Asteraceae: Astereae: Baccharidinae), a group from the southeastern South American grasslands and savannas, Phytotaxa 241 (1), pp. 448-450 : 448-450

Phytotaxa 241 (1) © 2016 Magnolia Press • 37 8. Baccharis leucopappa Candolle (1836: 415) . Baccharis helichrysoides var. leucopappa (DC.) Baker (1882: 51) . Lanugothamnus leucopappus (DC.) Deble (2012: 13) . Type:— BRAZIL. Rio Grande do Sul: [between Encruzilhada do Sul and Caçapava do Sul fide Malagarriga (1957)], ♀, F. Sellow 3111 = M. I. B. 830 (holotype P! (00755454); isotypes B! (100093163), G-DC! (G00200391), P! (00755455)).

Illustrations: — Baker (1882: tabula 21: II, as B. helichrysoides var. leucopappa ); Barroso (1976: 211, 218, 224); Malagarriga (1973: fig. 16; 1977: dessin 62). Fig. 20 , 21 .

Subshrubs 0.5–1 m tall, erect; fertile shoots ascending, branches axillary. Stems light brown, shoots villose. Leaves 0.7–3.3 cm long, 3–9 mm wide, sessile, evenly distributed along the branches; leaf blade thin to indurate, ovate to cordate, apex acute, base truncate, subcordate to cordate, margins entire, plane or revolute; leaves 1- nerved, adaxial surface with a caducous pilose indumentum, abaxial surface with a persistent tomentose indumentum. Capitulescences corymbose, terminal; 1.5–8 cm long, 2–7 cm wide. Capitula pedunculate; peduncles 0.1–1.3 cm long, villose. Male capitula 3.8–5 mm long; involucre 3–4.6 mm long, 4.3–7.9 mm wide, campanulate; phyllaries 3–4-seriate, white, outer ones ovate, median and inner ones oblanceolate, margins entire, apex acute, villose; clinanthium plane, glabrous; florets 45–68; corollas 2.2–2.7 mm long, tube 0.8–1 mm long, throat 1.1–1.3 mm, lobes 0.3–0.4 mm long, biseriate hairs on the lobes; anthers white, 2.2–2.7 mm long; style 2.3–2.8 mm long; ovary abortive, 0.05–0.07 mm long, 0.1–0.12 mm wide, covered by filiform trichomes; pappus 2.8–3.4 mm long, bristles 16–20, flexuous, apically not broadened. Female capitula 4.9–7.3 mm long; involucre 4.1–6 mm long, 4.8–6.5 mm wide, cylindrical to campanulate; phyllaries 4–6-seriate, white, outer ones elliptic, median and inner ones linear-lanceolate, margins entire, apex acute, villose; clinanthium plane, nearly glabrous, with scarce flagelliform and biseriate trichomes; florets 58–80; corollas 2.6–3.3 mm long; style 2.9–3.3 mm long, branches 0.3–0.4 mm long. Cypselae 0.9–1.1 mm long, 0.35–0.47 mm wide, stramineous, sericeous, evenly covered by twin trichomes, obconical, 4–5-ribbed; pappus 2.4–3.6 mm long, deciduous; bristles 38–48, not broadened apically, accrescent. Chromosome number unknown.

Etymology: —The specific epithet refers to the white colour of the pappus bristles.

Distribution and habitat: — Baccharis leucopappa occurs in southern Brazil (Rio Grande do Sul and Santa Catarina states), known from some disjunct locations from the Serra Geral and the eastern hills of Serra do Sudeste and surrounding lowland areas, at elevations between 50 and 950 m a.s.l. (Fig. 19). It forms sparse populations on rocky basaltic soil, within the subtropical highland grasslands of the Paranense province, and on granitic, sandstone or basaltic outcrops or rocky and shallow soils, in the low altitude temperate grasslands, within the Pampean province.

FIGURE 19. Distribution of Baccharis gnaphalioides (○) and B. leucopappa (Δ).

38 • Phytotaxa 241 (1) © 2016 Magnolia Press

HEIDEN & PIRANI

Phenology: —Fertile specimens have been collected from the end of September to early December, with a flowering peak in November.

TAXONOMY OF BACCHARIS SUBGEN. TARCHONANTHOIDES

Phytotaxa 241 (1) © 2016 Magnolia Press • 39

Conservation status: —Vulnerable (VU D2). Baccharis leucopappa is represented only in few conservation units and in non-protected primary sites. The populations are naturally fragmented and the area of occupancy is

40 • Phytotaxa 241 (1) © 2016 Magnolia Press

HEIDEN & PIRANI restricted. Few populations still persist, all of them under anthropogenic pressure caused by urbanization and extensive cropland, leading to the habitat suppression and loss of habitat quality.

Vernacular names: —Vassourinha-do-barranco (Heiden & Iganci 2142, 2143).

Comments: —Since Baker (1882), there is a great confusion in the application of the names Baccharis leucopappa and B. phylicifolia . Baker (1882) proposed the combination B. helichrysoides var. leucopappa , provided a short description and illustration for its variety, and did not mention B. phylicifolia in Flora brasiliensis . The analysis of the short description and illustration provided by that author, and the study of the type specimens of B. leucopappa and B. phylicifolia , lead to the conclusion that B. helichrysoides var. leucopappa fide Baker (1882) is the same taxon represented by the type specimen of B. phylicifolia , while the type specimen of B. leucopappa belongs to a clearly distinct species. Probably as a result of the misapplication by Baker (1882) of the name B. leucopappa, Barroso (1976) , Malagarriga (1977) and Barroso & Bueno (2002) based the circumscription of B. leucopappa on specimens belonging to both B. leucopappa and B. phylicifolia , while Barroso (1976), Barroso & Bueno (2002) and Deble (2012) applied the name B. phylicifolia to specimens belonging to B. uleana .

Thus, in the current taxonomic revision the application of the name B. leucopappa is clarified as referring to a species occurring solely in rather dry environments in the states of Santa Catarina and Rio Grande do Sul, while B. phylicifolia is a species widely distributed in moist or flooded habitats from the mountains of Itatiaia on the boundary between Minas Gerais and Rio de Janeiro, south to the highlands of northeastern Rio Grande do Sul. Baccharis leucopappa is a shrub with ascending villose shoots (vs. virgate tomentose shoots in B. phylicifolia ), presenting leaves with a caducous pilose indumentum adaxially (vs. leaves with a caducous, deciduous or persistent sericeous indumentum adaxially), with male florets lobes glabrous (vs. male florets with filiform trichomes on lobes) and sericeous cypsela (vs. puberulous).

Specimens examined: — BRAZIL. RIO GRANDE DO SUL: Barra do Ribeiro , 1 November 2013, ♂, G . Heiden & J. R. V . Iganci 2142 ( SPF); ♀, G . Heiden & J. R. V . Iganci 2143 ( SPF). Cacequi, Sangão do Macaco Branco , 28 September 1983, ♂, R . Bueno s.n. ( ICN 92617 ). Cambará do Sul , December 2000, ♀, M . Sobral & A. L . Silva 9188 ( ICN, MBM). Caxias do Sul, Vila Oliva , 30 May 1954, st., P . Buck s.n. ( PACA 37167 ). Jaguari, 26 September 1985, ♂, S . Eisinger & B . Irgang s.n. ( ICN 81133 ). Jaquirana, 1150 m, 9 November 1961, ♀, G . Pabst 6678 & E . Pereira 6852 ( B, HB, PEL, RB); Parque Estadual do Tainhas , 3 November 2013, ♂, G . Heiden & J. R. V . Iganci 2145 ( SPF). Mariana Pimentel, Reserva Biológica de Cerro Alegre , s.d., ♂, N. I . Matzenbacher s.n. ( RB 191676 ). Pareci Novo, 14 October 1945, ♂ & ♀, E . Henz s.n. ( PACA, SI). Parobé, Santa Cristina do Pinhal , 9 September 2002, st., S . Bordignon s.n. ( ICN 129249 ). Portão, ♂, 23 September 1949, B . Rambo 43509 ( LIL, PACA). Porto Alegre , 5 October 1940, ♂, T . Luis & E . Maria 4101 ( LP, MT, SPF); Morro da Polícia , 20 September 1948, ♂, B . Rambo 37696 ( LIL, PACA, SI); Morro Santana , 14 July 2008, st., T. L. S . Alves 6 ( ICN); 138 m, 4 October 2007, ♂, A. C . Fernandes & M . Ritter s.n. ( ICN 158663 ); 8 October 2004, ♂, G. H . Silveira 283 ( ICN). Rio Pardo , 24 October 1978, ♂, J . Mattos 19919 ( HAS). São Francisco de Assis , 24 October 2012, ♂, G . Heiden et al. 2000 ( SPF); ♀, G . Heiden et al. 2001 ( SPF); vale do rio Ibicuí , 24 October 2012, bud, G . Heiden et al. 2004 ( SPF). São Francisco de Paula , 21 October 2012, ♂, G . Heiden et al. 1974 ( SPF); ♀, G . Heiden et al. 1975 ( SPF). São Leopoldo , 6 November 1946, ♂ & ♀, E . Henz s.n. ( NY, PACA, S, SI); September 1941, st., J. E . Leite 2822 ( SP); Morro das Pedras , October 1932, ♂, G . Malme 1397 ( S); Vila Diehl , 5 November 1949, ♀, B . Rambo 44258 ( LIL, PACA). Sapucaia do Sul, morro Sapucaia , s.d., ♀, J. E . Leite 692 ( NY); s.d., ♀, J. E . Leite 2129 ( SP); 5 September 1945, ♂, B . Rambo 29543 ( PACA, SI); 10 November 1948, ♀, B . Rambo 37913 ( B, LIL, PACA); 17 October 1949, ♀, B . Rambo 43927 ( B, LIL, PACA); 17 October 1949, ♂ & ♀, B . Rambo 43928 ( LIL, PACA); 5 November , 1949, ♂, B . Rambo 44256 ( B, LIL, PACA); ♀, B . Rambo 44258 ( PACA); 1 September 1956, ♂, B . Rambo 57463 ( B, PACA, S). Viamão, Parque Estadual de Itapuã , October 1983, ♂ & ♀, M . Sobral 2430 ( F, MBM); morro do Araçá , 13 November 2002, M . Pinheiro 493 ( ICN) . SANTA CATARINA: Capão Alto, 3 November 2013, ♂, G . Heiden & J. R. V . Iganci 2147 ( SPF); ♀, G . Heiden & J. R. V . Iganci 2148 ( SPF). Lajes, morro do Pinheiro Seco , 1 November 1963, ♂, R. M . Klein 4502 ( FLOR, HBR, LP, RB) .

V. Baccharis ser. Canescentes (Giuliano) G.Heiden , stat. nov. Baccharis sect. Canescentes Giuliano (2005: 535) . Type:— Baccharis helichrysoides DC.

Male floret lobes with filiform trichomes.

TAXONOMY OF BACCHARIS SUBGEN. TARCHONANTHOIDES

Phytotaxa 241 (1) © 2016 Magnolia Press • 41 Baccharis ser. Canescentes represents a lineage of five species easily recognized by the peculiar presence of long tortuous filiform trichomes on the lobes of male florets. Most of the species of the series occur in moist or water satured environments such as forest edges, peat bogs and acid swamps.

Figures

FIGURE 20. Baccharis leucopappa. A. Fertile shoot of pistillate plant. B. Leaves. C. Portion of villose peduncle. D. Male capitulum. E. Phyllaries of male capitulum (outer to inner). F. Male floret. G. Female capitulum. H. Phyllaries of female capitulum (outer to inner). I. Female floret. J. Corolla and style of female floret. K. Cypsela. A, C, G–K: Heiden 1975 (SPF). B (from left to right): Heiden 2001 (SPF); Heiden 1975 (SPF); Heiden 2143 (SPF); Rambo 37696 (PACA). D–F: Heiden 1976 (SPF). Illustration by João Iganci.

FIGURE 21. Baccharis leucopappa. A. Habitat and habit on sandstone and basaltic outcrops in the low altitude temperate grasslands at São Francisco de Assis, Rio Grande do Sul, Brazil. B. Habit. C. Shoot. D. Male capitulescences. E. Female capitulescence. Photos by G. Heiden.