Chromolaena ivifolia (Linnaeus) King & Robinson (1970c: 202)

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 : 166-170

2.7. Chromolaena ivifolia (Linnaeus) King & Robinson (1970c: 202) .

Eupatorium ivifolium Linnaeus (1759: 1205) . Osmia ivifolia (L.) Schultz-Bipontinus (1866: 252). Lectotype (designated by King & Robinson 1975: 924):— JAMAICA. s.l., s.d., P. Browne s.n. (LINN! [LINN978.28]).

= Eupatorium affine Hooker & Arnott (1836: 240) . Eupatorium conyzoides var. affine (Hook. & Arn.) Baker (1876: 278) . Lectotype (designated by Freire & Ariza Espinar 2014b: 334):— ARGENTINA . Interior of Entre Rios, s.d. J. Tweedie s.n. (E! [E00249910], isolectotype K! [000486880]).

= Eupatorium concinnum Hooker & Arnott (1836: 239) , non Candolle (1836: 156) (= Neocabreria concinna King & Robinson 1972: 152 ). Type:— BRAZIL. Rio Grande do Sul, s.d., J. Tweedie s.n. (holotype E! [E00249919]).

= Eupatorium obscurum Candolle (1836: 142) . Osmia obscura (DC.) Schultz-Bipontinus (1866: 252) . Type:— BRAZIL. s.l., s.d., C. Gaudichaud s.n. (holotype P! [P02399637], isotype G-DC! [G00465921]).

= Ooclinium clavatum Bentham (1838: 108) . Osmia gracilima Schultz-Bipontinus ex Baker (1876: 290) nom. nud. pro syn. Osmia stenophylla Schultz-Bipontinus ex Baker (1876: 290) nom. nud. pro syn. Eupatorium ivifolium var. gracilimum Baker (1876: 290) . Type:— GUIANA. s.l., 1836, M.R. Schomburgk 165 (holotype K! [K000486812]).

= Eupatorium fasciculare Poeppig (1845: 54) . Type:— PERU. Cessapi, 1829, E.F. Poeppig 1660 (holotype W, isotype F! [V0043793F]).

= Eupatorium ivifolium var. serratum Grisebach (1866: 146) . Type:— CUBA . s.l., 1860, C. Wright 2800 (holotype GOET, isotype K! [K000373092]).

= Eupatorium ivifolium var. extrorsum Baker (1876: 290) . Eupatorium extrorsum Schultz-Bipontinus ex Baker (1876: 290) nom. nud. pro syn. Types:— BRAZIL. São Paulo: Sorocaba, s.d., Riedel s.n. (syntype K! [K000486810]); Minas Gerais: Lagoa Santa, s.d., E. Warming 516 (syntype P! [P02399700]).

= Eupatorium ivifolium var. laxiflorum Baker (1876: 290) . Type:— BRAZIL. Maranhão, 1837, Pohl 289 (holotype K! [K000486814]).

= Eupatorium ivifolium var. asperum Baker (1876: 291) . Type:— BRAZIL. Goiás: Arraias, May 1840, Gardner 4207 (holotype K! [K000373091]).

= Eupatorium luquense Chodat (1901: 413) . Chromolaena luquensis (Chodat) King & Robinson (1970c: 203) . Lectotype (designated by Freire & Ariza Espinar 2014b: 334):— PARAGUAY. Sapucay, 1885, E. Hassler 1657 (G! [G00381968], isolectotypes K! [K000486804], P! [P00742480], NY! [NY169094]).

= Eupatorium ivifolium var. foliosum Chodat (1902: 307) . Type:— PARAGUAY. Luque, March 1875, B. Balansa 939 (holotype G! [G00381851]).

= Eupatorium ivifolium var. hirsutum Hassler (1916: 280) . Lectotype (designated by Freire & Ariza Espinar 2014b: 334):— PARAGUAY. Santa Elisa, March 1903, E. Hassler & T. Rojas 2788 (G! [G00381965[, isolectotypes K! [K000486811], BM]

= Eupatorium ivifolium var. pilcomayense Hassler (1916: 280) . Type:— PARAGUAY. Gran Chaco: Pilcomayo river, June 1906, T. Rojas 236 (holotype G, isotype BM! [BM000096343]).

= Eupatorium ivifolium var. perturbinatum Robinson (1928: 23) . Type:— ARGENTINA . Formosa: Guayalec, September 1909, P. Jörgensen 3351 (holotype GH! [GH00007734], isotype SI). ( Fig. 14A–E , 15A–B ).

Subshrubs, up to 1.5 m tall, erect, xylopodium absent, branched from base or only in capitulescence; stems puberulous to hirsute, eglandular or rarely glandular, leafy until capitulescence. Leaves 1.7–8.9 × 0.4–4.4 cm, opposite, sessile to petiolate, 3-veined, leaf blade lanceolate to linear, papyraceous to chartaceous, apex acute to obtuse, base acute to cuneate, rarely rounded, margins entire to serrate in apical half, entire in basal half, adaxial surface glabrous to strigose, eglandular, abaxial surface strigose to rarely hirsute on veins, glandular, margins ciliate; petioles up to 1.4 cm long, hirsute, eglandular. Primary capitulescences corymbose. Secondary capitulescences corymbose to paniculate, axis puberulous to hirsute, glandular or eglandular, bracteate, bracts 0.9–8.5 × 0.2–2 cm, petioles up to 1.5 cm long, hirsute, eglandular. Capitula subsessile to pedunculate, peduncles 0.4–1.6 cm long, puberulous, glandular or eglandular, involucres cylindrical to campanulate, 5.5–7.8 × 2.7–4 mm, involucral bracts 22–40, 6–7-seriate, outer ovate to oblong, 1.4–2.9 × 1–1.6 mm, apex rounded to truncate, vinaceous, ciliate or eciliate, glabrous to puberulous, glandular or rarely eglandular, recurved to slightly recurved, abaxial surface stramineous to citrine, 3–5-veined, glabrous, inner spatulate to linear, 5–7.5 × 0.7–1.1 mm, apex rounded, pink, non-petaloid, eciliate, glabrous, eglandular, slightly recurved to erect, abaxial surface stramineous to citrine, 3–4-veined, glabrous, receptacles epaleate or rarely paleate, paleae 0–2, linear, 3.2–7 × 0.2–0.7 mm, 1–3-veined, apex stramineous to pink, abaxial surface stramineous, eciliate, eglandular. Florets 18–27, corollas 3.3–4.8 × 0.4–0.9, lilac, lobes glabrous, glandular. Cypselas obconical, 2–3.4 × 0.4–0.8 mm, 5–7-ribbed, ribs and sinuses glabrous to setuliferous, eglandular, pappus setae ca. 25–40, white to stramineous, 3.8–4.9 mm long.

Distribution: —Tropical America, from southern United States to northern Argentina ( Esteves 2001) . In Brazil, it occurs in Espírito Santo, Minas Gerais, Rio de Janeiro, Rondônia, São Paulo, Tocantins and all states of the Midwestern and Southern regions. In Rio Grande do Sul, it occurs in all physiographic regions with the exception of Missões ( Fig. 16 , triangles).

Habitat: —Grasslands or forest edges in both Atlantic Forest and Pampa biomes, without any clear environmental preferences. It is also a common species in anthropogenic sites.

Phenology: —Flowers during summer and autumn, with a flowering peak in March and April.

Etymology: —The specific epithet is a reference to the leaves of genus Iva L. ( Asteraceae ), to which the leaves of this species bear some similarity.

Comments: — Chromolaena ivifiolia is one of the three species with the greatest geographical range of the genus, along C. laevigata and C. odorata . It is one of the most common species found in Rio Grande do Sul, particularly in anthropogenic sites such as roadsides, where it tends to form dense populations.

We agree with the observations of Matzenbacher (1979) and Esteves (2001), who noted that C. ivifolia is subject to a significant variation in some of its morphological characters, particularly the indumentum of stems and leaves, the shape and size of leaves, and the indumentum, shape and curvature of the apices of the outer involucral bracts. However, the characters of the inner involucral bracts, mainly the shape of the apex and the pink coloration are constant among the specimens analyzed, suggesting it to be a strong morphological feature to recognize this species.

Morphologically, the closest species to C. ivifolia found in Rio Grande do Sul is C. callilepis . The differences between these species were pointed under the description of the latter.

The great variation of most of its morphological characters makes its identification sometimes complex, resulting in many misidentifications with similar species. Chromolaena ivifolia is often mistaken for C. verbenacea : both species share many similar characters, mostly in the vegetative organs. Chromolaena ivifolia differs from C. verbenacea by the smaller leaves, with never attenuate base and always with abaxial surface densely glandular; the greater number of florets; the smaller capitula; and the outer involucral bracts never glabrous, always glandular and with apex slightly recurved to recurved. Chromolaena ivifolia is also sometimes mistaken for C. hirsuta and C. pedunculosa . It differs from the latter mostly due to the smaller capitula and the outer involucral bracts with more or less recurved apices, never glabrous and always glandular (vs. involucral bracts with always appressed apices, always glabrous and never glandular) and from the former by the greater number of florets, general shape of the leaves, absence of glandular hairs in the cypselas and by the inner involucral bracts with pink, rounded apices.

Specimens examined: — BRAZIL: Rio Grande do Sul: Alegrete: BR 290 , Km 468, 03 April 1977, Porto, M. L., Irgang, B. et. al. 2420 ( ICN). Arroio dos Ratos: Granja Faxinal, 20 April 1979, Hagelund, K. 12778 ( ICN). Bom Jesus: s.l. [28°44’S, 50°26’W], 25 March 2017, Christ, A. L. 404 ( ICN). Caçapava do Sul: s.l., 11 April 2008, Schneider, A. A. 1596b ( ICN). Cachoeira do Sul: Mina Iruí, April 1985, Sobral, M. 3831 ( ICN). Canoas: s.l., February 1944, Augusto, I. s.n. ( ICN18052 ). Carazinho: s.l., February 1944, Augusto, I. s.n. ( ICN18032 ). Caxias do Sul: Ana Rech, Faxinal, 17 March 1989, Brinker, J. et al. s.n. ( HUCS05512 ) ; RS-122, 15 April 2012, Wasum, R. 4984 ( HUCS, MBM) ; Criúva, Cânion dos Palanquinhos, 04 February 2017, Gonzatti, F. 3337 ( HUCS). Giruá : Granja Sodal, March 1964, Hagelund, K. 1931, 2185, 2186, 2202, 2243 ( ICN) ; entre Giruá e Santa Rosa , 03 April 1979, Hagelund, K. 12736 ( ICN). Guaíba : BR 116 , Km 32, 18 March 1975, Matzenbacher, N. I. 163 ( ICN) ; Fazenda São Maximiano, BR 116 , Km 308, 28 March 2009, Matzenbacher, N. I. s.n. ( ICN153063 ). Ijuí: Rua Dr. Pestana, 19 February 1952, Pivetta, J. 355 ( PACA). Mariana Pimentel: Colônia do Podocarpus, 14 May 1978, Matzenbacher, N. I. s.n. ( ICN170494 ). Nonoai: Rio Uruguai , March 1945, Rambo, B. s.n. ( PACA28179 ). Osório: s.l., 27 March 1950, Rambo, B. s.n. ( ICN16304 ). Pelotas: s.l., 11 March 1957, Sacco, J. C. 611 ( PACA) ; s.l., 14 February 1967, Cardoso, E. 16 ( HBEI). Porto Alegre: Faculdade de Agronomia, 10 March 1975, Arzivenco , L. s.n. ( ICN67777 ). Rosário do Sul: s.l. [30°15’S, 54°32’], 28 November 2016, Christ, A. L. 313 ( ICN). Santa Cruz do Sul: Trombudo, 01 March 1976, Waechter, J. L. 227 ( ICN). Santana do Livramento : Cerro do Armour , 26 March 1976, Irgang, B. s.n. ( ICN32370 ). Santa Maria: Estação Experimental da Silvicultura , 10 April 1956, Camargo, O. R. 500 ( PACA) ; s.l., May 1985, Sobral, M. 3883 ( ICN) ; Campus da UFSM, atrás do CEFD, 14 January 1994, Ethur , L. s.n. ( SMDB5072 ) ; Campus da UFSM, 08 June 1994, Ethur, L. s.n. ( SMDB5440 ) ; Pains, antiga fazenda de Valter Moreira, 20 March 2015, Christ, A. L. 64 ( SMDB) ; CISM, proximidades da antiga fazenda Sarandi, 17 April 2015, Christ, A. L. 114 ( SMDB). São Francisco de Paula : RS-235, 25 March 2001, Wasum, R. 1027 ( HUCS) ; 24 March 2002, Wasum, R. 1437 ( HUCS) ; entre São Francisco e Jaquirana, 18 March 2017, Christ, A. L. 376 ( ICN). São Gabriel: Fazenda Santa Cecília , January 1944, Rambo, B. s.n. ( PACA25771 ) ; BR 290 , próximo ao Km 302, 27 March 1985, Bueno, O. et. al. 4248 ( MBM) ; s.l., 11 April 2008, Schneider, A. A. 1595 ( ICN) ; FEPAGRO, 02 April 2014, Barão, C. F. 36 ( HBEI) ; s.l., 17 June 2014, Barão, C. F. 46 ( HBEI). São Jerônimo: BR 290 , Km 58, 1979, Hagelund, K. 12725 ( ICN). São João do Polêsine: Vale Vêneto , 09 April 1956, Sehnem, A. 1333 ( PACA). São Leopoldo: Sapucaia, 22 April 1937, Dutra , J. s.n. ( ICN15638 ) ; s.l., 16 April 1946, Henz, E. s.n. ( PACA33525 ). Três de Maio: BR 462 , Km 134, 13 April 2017, Christ, A. L. 436 ( ICN). Tupanciretã: s.l., 29 January 1942, Rambo, B. s.n. ( PACA9820 ). Vacaria: Hidráulica de Vacaria , 28 February 1976, Arzivenco, L. s.n. ( ICN42116 ) ; Parque das Cachoeiras, Refugiados, 26 March 2017, Gonzatti, F. 3466 ( HUCS) .

Figures

FIGURE 14A–E: Chromolaena ivifolia.A. Fertile specimen. B. Capitulum. C. Involucral bracts. D. Floret. E. Palea. F–J: Chromolaena laevigata. F. Fertile branch. G. Capitulum. H. Involucral bracts. I. Floret. J. Palea.

FIGURE 15A–B: Chromolaena ivifolia. A. General view. B. Capitula. C–E: Chromolaena laevigata. C. General view. D. Capitula. E. Secondary capitulescence. Credits: Anderson Christ (A–C) and Sérgio Bordignon (D–E).

FIGURE 16: Distribution of C. ivifolia (triangles) and C. laevigata (circles) in Rio Grande do Sul.