Chromolaena pedunculosa (Hooker & Arnott) King & Robinson (1980b: 231)

Christ, Anderson Luiz & Ritter, Mara Rejane, 2019, A taxonomic study of Praxelinae (Asteraceae-Eupatorieae) in Rio Grande do Sul, Brazil, Phytotaxa 393 (2), pp. 141-197 : 181

2.12. Chromolaena pedunculosa (Hooker & Arnott) King & Robinson (1980b: 231) .

Eupatorium pedunculosum Hooker & Arnott (1836: 240) . Type:— BRAZIL. Rio Grande do Sul, s.d., J. Tweedie s.n. (holotype K! [K000486793]).

= Eupatorium foliatum var. incanum Hieronymus (1897: 749) . Lectotype (designated by Freire & Ariza Espinar 2014b: 338):— ARGENTINA . Misiones: Cierro de Santa Ana, s.d., G. Niederlein 4636 (GH! [GH00007677]).

= Eupatorium conyzoides var. foliatum Baker (1876: 278) . Eupatorium foliatum (Baker) Hieronymus (1897: 748) . Chromolaena foliata (Baker) King & Robinson (1970: 201) . Lectotype (designated by Freire & Ariza Espinar 2014b: 338):— BRAZIL. s.l., s.d., F. Sellow 2581 (GH! [GH00257069]). ( Fig. 20E–I , 23A–C ).

Subshrubs to shrubs, up to 2 m tall, erect, xylopodium absent, branched only in capitulescence; stems puberulous to villose, glandular or eglandular, leafy until capitulescence. Leaves 4–9.5 × 1.2–5 cm, opposite, petiolate, 3-veined, leaf blade ovate to lanceolate, papyraceous, apex acuminate to obtuse, base cuneate to attenuate, rarely rounded, margins crenate to serrate, rarely entire, adaxial surface strigose, eglandular, abaxial surface strigose only on veins to tomentose, glandular, margins ciliate, petioles 0.4–2.5 cm long, puberulous to villose, glandular or eglandular. Primary capitulescences corymbose. Secondary capitulescences paniculate, axis strigose to villose, glandular or eglandular, bracteate, bracts 0.8–8.2 × 0.2–4.2 cm, sometimes with base rounded and margins entire, petioles 0.1–1.6 cm long, puberulous to villose, glandular or eglandular. Capitula subsessile to long pedunculate, peduncles 0.2–3.3 cm long, puberulous, eglandular or rarely glandular, involucres cylindrical, 7.5–10 × 2.4–4.4 mm, involucral bracts 25–36, 6–7-seriate, outer ovate to oblong, 1.9–3.4 × 1.2–2 mm, apex rounded to cuneate, stramineous to vinaceous, ciliate, glabrous, eglandular, appressed, abaxial surface stramineous to citrine, 3–6-veined, glabrous, inner linear, 6.6–9.7 × 0.7–1.1 mm, apex rounded to obtuse, stramineous to vinaceous, non-petaloid, ciliate, glabrous, eglandular, appressed, abaxial surface stramineous to citrine, 3-veined, glabrous, receptacles epaleate or paleate, paleae 1–4, linear, 6.9–9.3 × 0.2–0.7 mm, 1-veined, apex and abaxial surface stramineous, ciliate, eglandular. Florets 20–35, corollas 4–6 × 0.4–1 mm, lobes glabrous to puberulous, glandular. Cypselas obconical, 2.4–4.2 × 0.4–07, 4–6-ribbed, ribs and sinuses glabrous to setuliferous, eglandular, pappus setae ca. 30–40, white to stramineous, 4.4–5.8 mm long.

Distribution: — Argentina , Brazil and Paraguay ( Freire & Ariza Espinar 2014b). In Brazil, it occurs in Minas Gerais, Paraná, Rio Grande do Sul, Santa Catarina and São Paulo. In Rio Grande do Sul, it occurs in all physiographic regions, except in the Encosta do Sudeste ( Fig. 21 , circles).

Habitat: —Forest edges of biomes Atlantic Forest and Pampa, usually in shadowy environments. The species can also be found in grasslands, although in a lesser degree. It is also common in anthropogenic sites, mostly in roadsides.

Phenology: —Flowers from the end of summer to the beginning of autumn, with a flowering peak from March to May.

Etymology: —Latin pedunculosus (bearing a peduncle), in reference to the usually long peduncles of the capitula.

Comments: — Chromolaena pedunculosa is a very common species in Rio Grande do Sul, mostly in forest edges and anthropogenic sites such as roadsides. This species shows notable morphological variations in the vegetative characters, principally in the indumentum of leaves and stems, the size of the leaves and the length of the internodes. These variations have led to several identification problems involving this species and other similar species such as C. paraguariensis and C. ulei . Another character of this species that contributes to the difficulty in identifying C. pedunculosa is its large capitulescence, in general too big and voluminous to be collected in its entirety. As a result, most of the herbarium sheets consist of only fragments of the capitulescence. The axes usually show a different, sparser indumentum than the rest of the plant, and the bracts usually have rounded bases and entire margins, in direct contrast to the leaves. Thus, sheets consisting of only fragments of the capitulescence tend to be very different from the ones containing entire specimens, what usually leads to misidentifications.

Chromolaena pedunculosa can be recognized by the ovate to lanceolate leaves, in general with a strigose indumentum in the abaxial surface; by the puberulous to villose indumentum of the stem; and by the capitula generally long pedunculate with all involucral bracts with glabrous, eglandular and appressed apices. The most similar species to C. pedunculosa found in Rio Grande do Sul are C. paraguariensis and C. ulei . The differences between C. pedunculosa and the former were commented under its description. Chromolaena ulei differs from C. pedunculosa by the shape, margins and indumentum of the leaves, the indumentum of the stem and the general aspect of the capitulescence, which tends to be more condensed. Chromolaena ulei also usually has shorter internodes and more tightly arranged leaves.

Specimens examined: — BRAZIL: Rio Grande do Sul: Arroio dos Ratos: Granja Faxinal , 13 March 1982, Hagelund, K. 13841 ( ICN). Arvorezinha: s.l. [28°49’59’’S, 52°15’42’’W], 14 March 2005, Marchetti, M. & Born, T. s.n. ( HVAT1819 ) ; 28 March 2015, Scherer, L. C. s.n. ( HVAT3603 ). Bento Gonçalves: Pinto Bandeira, 25 February 1985, Stehmann, J. R. 527 ( ICN). Bom Jesus: Rodovida Bom Jesus a São Joaquim, 11 March 2005, Hatschbach, G., Barbosa, E. & Costa, E. F. 79057 ( MBM, FURB) ; Rio Tainhas , 19 March 1999, Rossato, M. & Wasum, R. 57 ( HUCS, MBM, PACA) ; s.l. [28°46’S, 50°28’W], 25 March 2017, Christ, A. L. 410, 411 ( ICN). Caçapava do Sul: BR-290, Km 223, May 1985, Sobral, M. 3909 ( ICN, MBM) ; s.l., 12 April 2008, Schneider, A. A. 1597 ( ICN). Campo Bom: s.l. [29°39’41,6’’S, 51°02’39,1’’W], 01 March 2014, Silva Filho, P.J.S. 2039 ( ICN). Canela: Caracol, 09 March 1954, Emrich, K. s.n. ( PACA54251 ). Carazinho: s.l., February 1944, Augusto, I. s.n. ( ICN18037 ). Caxias do Sul: s.l., 1932, Augusto, I. s.n. ( PACA11858 ) ; estrada para Loreto , 27 May 1985, Guerra, I. et al. s.n. ( HUCS888 ) ; Mato Perso , 23 March 1986, Wasum, R. et al. s.n. ( HUCS1427 ) ; Faxinal , 26 February 1999, Scur, L. 30 ( HUCS, MBM) ; Vila Cristina , 22 March 1999, Kegler, A. 231 ( MBM) ; Jardim Botânico , 23 March 2004, Wasum, R. 2122 ( HUCS, MBM) ; Criúva, linha Taimbé , 29 April 2005, Wasum, R. 2929 ( HUCS) ; rodovia RS-122, 15 April 2012, Wasum, R. 4981 ( HUCS, MBM). Dois Irmãos: Morro Reuter, 29 March 1987, Wasum, R. et al. s.n. ( HUCS2595 ). Dom Pedrito: Estância São Salvador, 14 March 1947, Sehnem, A. s.n. ( HUCS1014 ). Dom Pedro de Alcântara : s.l., 19 December 1997, Dalpiaz, S. & Baptista , L. R. M. s.n. ( ICN115239 ) ; [29°22’58,91’’S, 49°50’16,69’’W], 21 January 2005, Maraschin-Silva, F. s.n. ( ICN137108 ). Erechim: IBDF, 06 April 1993, Butzke, A. et al. s.n. ( HUCS10674 ). Esmeralda: s.l., 02 April 1978, Arzivenco, L. 7 ( ICN). Farroupilha: s.l., 18 March 1957, Camargo, O. R. 1167 ( PACA) ; 07 May 1957, Camargo, O. R. 1352 ( PACA) ; São Roque , 19 April 1985, Dal Pont, V. et al. s.n. ( HUCS652 ) ; Parque dos Pinheiros, 14 May 2005, Meneghel, R. 5, 8 ( HUCS) ; 08 June 2005, Meneghel, R. 28, 35, 36 ( HUCS). Flores da Cunha: Otávio Rocha , 06 May 1984, Oliveira, F. et al. s.n. ( HUCS59 ) ; estrada para Antônio Prado , 22 June 1998, Wasum, R. & Molon, R. C. s.n. ( HUCS12617 ). Garibaldi: Marcorama, Vila Santana, 15 May 1988, Wasum, R. et al. s.n. ( HUCS4219 ). General Câmara: Santo Amaro, March 1996, Carneiro, A. 1 ( ICN). Giruá: Granja Sodal, March 1964, Hagelund, K. 2034 ( ICN). Guaíba: s.l., 19 March 1978, Matzenbacher, N. I. s.n. ( ICN170493 ) ; Fazenda São Maxmiliano , 23 March 2009, Matzenbacher, N. I. s.n. ( ICN170916 ) ; 16 May 2010, Matzenbacher, N. I. 3041 ( ICN) ; 08 April 2013, Matzenbacher, N. I. s.n. ( ICN191053 ). Ijuí: Rua Dr. Pestana, 01 April 1954, Pivetta, J. 354 ( PACA). Jaquirana: Fazenda Rodeio Velho, 19 March 2006, Wasum, R. 3616 ( HUCS, ICN) ; propriedade do seu Ângelo [29°01’S, 50°24’W], 18 March 2017, Christ, A. L. 384 ( ICN). Lajeado: Jardim Botânico, 15 February 2007, Spellmeier, J. s.n. ( HVAT2318 ). Machadinho: Linha Santa Catarina, 15 February 2001, Antunes, J. s.n. ( PACA85732 ) ; 01 March 2001, Peloso, E. s.n. ( PACA85713 ). Marcelino Ramos: Sétimo Céu [27°28’02,8’’S, 51°54’18,8’’W], 02 March 1989, Jarenkow, J. A. 12751 ( MBM) ; 06 May 2008, Schneider, A. A. 1604 ( ICN). Mariana Pimentel: Colônia do Podocarpus , 08 April 1978, Matzenbacher, N. I. s.n. ( ICN170492 ). Montenegro: Kappesberg, 15 May 1945, Friderichs s.n. ( PACA29922 ) ; 14.III.1947, Sehnem, A. 2671 ( PACA) ; 14 March 1949, Sehnem, A. 3689 ( PACA). Nova Hartz: s.l., 10 June 2012, Silva Filho, P.J.S. & Molz, M. 1770 ( ICN). Nova Prata: Cascata da Usina, 02 March 1989, Wasum, R. et al. s.n. ( HUCS5357 ). Osório: Fazenda do Arroio , 14 April 1950, Rambo, B. s.n. ( PACA46832 ) ; Lagoa da Pinguela , 05 August 1950, Rambo, B. s.n. ( PACA46498 ) ; Laranjeiras , 27 March 1982, Sobral, M. 1044 ( MBM). Palmeira das Missões: s.l., 12 February 1951, Rambo, B. s.n. ( PACA50012 ). Pareci Novo: para Montenegro, 31 March 1950, Rambo, B. s.n. ( PACA50520 ). Passo Fundo: s.l., 04 July 1957, Freddiani, P. s.n. ( PACA60736 ) ; s.l., April 2009, Savaris, M. 48 ( ICN). Porto Alegre: Vila Manresa , 03 March 1949, Rambo, B. s.n. ( PACA40366 ) ; Agronomia , 25 April 1974, Matzenbacher, N. I. 52 ( ICN) ; Morro Santana , 28 April 2006, Fernandez, R. s.n. ( ICN158160 ) ; em frente ao campus Agronomia / UFRGS, 2009, Silva Filho, P.J.S. 944 ( ICN) ; Morro São Pedro, 17 March 2017, Christ, A. L. 359, 366 ( ICN). Quevedos: Margem do rio Toropi, 01 April 2006, Wasum, R. 3660 ( HUCS). Rolante: entre Rolante e Riozinho, próximo à Cascata do Chuvisqueiro , 11 April 2005, Mentz, L. A., Soares, E. L. C. & Vendruscolo, G. S. 368 ( ICN). Santa Maria: Estação Experimental da Silvicultura , 10 March 1956, Camargo, O. R. 20 ( PACA) ; 10 April 1956, Camargo, O. R. 456 ( PACA) ; Campo de Instrução de Santa Maria - CISM, proximidades do arroio Taquarichim, Christ, A. L. 118 ( SMDB) ; Cerrito, s.d., Rau, G. s.n. ( SMDB264 ). Santa Rosa : Campinas , February 1950, Spies s.n. ( PACA47385 ). Santa Tereza: s.l., 16 April 2010, Pasini, E. 380 ( HUCS) ; 16 May 2010, Pasini, E. 382 ( HUCS). Santo Ângelo: Boca do Mato , 18 February 1941, Rambo, B. s.n. ( PACA4679 ) ; Granja Piratini , 10April 1975, Arzivenco, L. s.n. ( ICN42975 ). Santo Cristo: Linha Guaraipo, 14 February 2017, Christ, A. L. 345 ( ICN). São Leopoldo: s.l., 1907, Theissen, F. s.n. ( PACA7987 ) ; 08 September 1934, Rambo, B. s.n. ( PACA1626 ) ; Quinta São Manoel , March 1936, Dutra , J. 1305 ( ICN) ; Sapucaia , 17 March 1949, Rambo, B. s.n. ( PACA40590 ) ; Cristo Rei , 10 March 1950, Rambo, B. s.n. ( PACA46224 ). São Marcos: Linha Zambecari, 19 March 2011, Rizzon, E. 105 ( HUCS). São Vendelino: s.l., 30 March 1993, Wasum, R. s.n. ( HUCS9083 ). Sapucaia do Sul: para São Leopoldo, 09 March 1949, Rambo, B. s.n. ( PACA40421 ). Soledade: s.l., 02 April 1979, Hagelund, K. 10049, 12789, 12795, 12798, 12799 ( ICN) ; para Ibirapuitã [28°37’S, 52°35’W], 08 February 2001, Schneider, A. A. 1782 ( ICN). Taquara: s.l., 07 April 1958, Mattos, J. 6871 ( PACA). Taquari: BR-386, Km 80, em direção a Venâncio Aires, 18 March 1978, Reis, I. 260 ( ICN). Terra de Areia: s.l. [29°33’11’’S, 50°03’03’’W], 18 March 2008, Schneider, A. A. 1582 ( ICN). Teutônia: Lagoa da Harmonia , 22 March 1992, Wasum, R. et al. s.n. ( HUCS8489 ). Torres: Colônia São Pedro, 27 March 1973, Hagelund, K. 12705 ( ICN) ; Faxinal em Butiazal, 29 April 2010, Iganci, J. R. V. 662 ( ICN). Três Coroas: s.l., April 1995, Sobral, M. et al. 7897 ( FURB, MBM). Três de Maio : BR-462, Km 134, 13 April 2017, Christ, A. L. 435 ( ICN). Venâncio Aires: s.l., 18 March 1978, Reis, I. 258 ( ICN). Viamão: Bairro Tarumã, região de entorno do Lago Tarumã, 30 March 2010, Silva Filho, P.J.S. 747 ( ICN) ; 05 May 2011, Silva Filho, P.J.S. 1368 ( ICN) ; Parque Estadual de Itapuã , s.d., Czykiel, R. s.n. ( ICN152475 ) .

Figures

FIGURE 20A–D: Chromolaena paraguariensis. A. Fertile branch. B. Capitulum. C. Involucral bracts. D. Floret. E–I: Chromolaena pedunculosa. E. Fertile branch. F. Capitulum. G. Involucral bracts. H. Floret. I. Palea.

FIGURE 21: Distribution of C. paraguariensis (triangles), C. pedunculosa (circles) and C. rhinanthacea (diamond) in Rio Grande do Sul.

FIGURE 23A–C: Chromolaena pedunculosa. A. General view. B. Capitula. C. Leaves. D–F: Chromolaena rhinanthacea. D. Leaves. E. Capitula. F. General view. Credits: Anderson Christ (A, D–F) and Sérgio Bordignon (B–C).