Chromolaena verbenacea (Candolle) King & Robinson (1970c: 207)

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 : 191-193

2.17. Chromolaena verbenacea (Candolle) King & Robinson (1970c: 207) .

Eupatorium verbenaceum Candolle (1836: 146) .Type:— BRAZIL. Rio Grande do Sul, 1833, C. Gaudichaud 760 (holotype P! [P00742723], isotype G-DC! [G00494039]).

= Eupatorium rhodolepis Chodat (1903: 705) . Eupatorium verbenaceum var. rhodolepis (Chodat) Hassler (1916: 283) . Type:— PARAGUAY. Valenzuela, February 1900, E. Hassler 7105 (holotype G! [G00381846]). ( Fig. 27A–E , 28E–F ).

Subshrubs, up to 2 m tall, erect, rarely decumbent, xylopodium absent, branched only in capitulescence; stems hirsute, rarely glabrous, eglandular, leafy until capitulescence. Leaves 1.7–8.3 × 0.7– 0.4 cm, opposite, petiolate, 3-veined, leaf blade ovate to lanceolate, papyraceous to chartaceous, apex acute to obtuse, base cuneate to attenuate, margins serrate to rarely crenate, adaxial surface glabrous to strigose, eglandular, abaxial surface strigose to hirsute only on veins, eglandular or rarely glandular, margins ciliate, petioles 0.3–2.3 cm long, hirsute, eglandular. Primary capitulescences corymbose. Secondary capitulescences corymbose, axis hirsute, eglandular, bracteate, bracts 0.6–6.1 × 0.2–2.9 cm, sometimes with margins entire, petioles 0.2–1.7 cm long, hirsute, eglandular. Capitula pedunculate, rarely subsessile, peduncles 0.2–2.3 cm long, strigose to hirsute, rarely glabrous or glabrescent, eglandular, involucres cylindrical, 7.2– 9.7 × 2.5–3.4 mm, involucral bracts 18–29, 5–6-seriate, outer ovate to oblong, 1.7–3.4 × 0.7–2 mm, apex rounded to obtuse, rarely cuneate, vinaceous or rarely stramineous, ciliate, glabrous, eglandular or rarely glandular, appressed, abaxial surface stramineous to vinaceous, 3–5-veined, glabrous, inner lnear, 6.3–8.4 × 0.7–1.2 mm, apex acuminate to rounded, vinaceous or rarely stramineous, non-petaloid, ciliate or eciliate, glabrous, eglandular, appressed, abaxial surface stramineous to vinaceous, 1–3-veined, glabrous, receptacles epaleate or rarely paleate, paleae 1–3, linear, 6.7– 8.2 × 0.4–0.5 mm, 1–3-veined, apex stramineous to vinaceous, abaxial surface stramineous, eciliate, eglandular. Florets 11–17, corollas 4–5.3 × 0.4–0.7, lilac, lobes glabrous to puberulous, eglandular or rarely glandular. Cypselas obconical to rarely oblong, 2.9–3.8 × 0.5–0.8 mm, 5–6-ribbed, ribs glabrous to puberulous, sinuses glabrous, eglandular, pappus setae ca. 27–40, white to stramineous, 4.2–5.4 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 the physiographic regions of Alto Uruguai, Campos de Cima da Serra, Depressão Central, Encosta Inferior do Nordeste, Missões and Planalto Médio ( Fig. 26 , circles).

Habitat: —Grasslands usually close to rocky outcrops or shallow soils in the Atlantic Forest biome, rarely in the Pampa.

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

Etymology: —The specific epithet is a reference to the species of the genus Verbena L. ( Verbenaceae ), particularly V. officinalis L., which is morphologically similar to this species.

Comments: — Chromolaena verbenacea is a rare species, being recorded in few localities of Rio Grande do Sul. However, it is common where it does occur, especially in the physiographic region of Campos de Cima da Serra, where it tends to appear in large, although sparse populations. It is easily recognizable by the hirsute indumentum of the stems, the leaves with cuneate to attenuate base and the involucral bracts with appressed and almost always vinaceous apices.

The most similar species to C. verbenacea to occur in Rio Grande do Sul is C. ivifolia . The differences between them were commented upon under the description of the latter.

Specimens examined: — BRAZIL: Rio Grande do Sul:Arroio do Meio: Morro Gaúcho, 13 March 2011, Bruisma, G. 188 (HVAT). Arroio dos Ratos: Granja Faxinal, 26 March 1976, Hagelund, K. 10034, 10220, 10221 (ICN). Bom Jesus: Fazenda Caraúna, 10 February 1934, Dutra , J. 1432 (ICN). Canela: Passo do Inferno, 10 February 1941, Rambo, B. s.n. (PACA4819). Cruz Alta: Fumagali, 24 January 1975, Arzivenco, L. s.n. (ICN45337); s.l., 27 February 1975, Arzivenco, L. s.n. (ICN67764). Erechim: Lago Menno, 31 March 1994, Butzke, A. 382 (HUCS). Giruá: Granja Sodal, 12 May 1963, Hagelund, K. 763, 765, 777, 778, 784 (ICN); March 1964, Hagelund, K. 2026, 2131, 2171, 2207, 2235 (ICN). Ijuí: Rua Dr. Pestana, 16 February 1956, Pivetta, J. 1152 (PACA). Jaquirana: propriedade das Irmãs, 19 March 2017, Christ, A.L. 391, 392 (ICN). Porto Alegre: Morro São Pedro, 02 April 2006, Setubal, R. 186 (ICN); Setubal, R. 524 (HUCS). Santa Maria: Campus UFSM, nos fundos do viveiro do Colégio Agrícola, 20 May 1993, Ethur, L.Z. s.n. (SMDB5145). Santa Rosa : 20 Km a sudeste de Santa Rosa , 02 November 1971, Lindeman, J.C., Irgang, B.E. & Valls, J.F.M. s.n. (ICN9006). Santo Antônio das Missões: estrada Santo Antônio-Tupanciretã, perto de Carajá, 16 November 1977, Fleig, M. 857 (ICN). São Miguel das Missões: Ruínas de São Miguel, 30 April 1982, Irgang, B.E. s.n. (ICN). Vacaria: Fazenda da Ronda, 06 January 1947, Rambo, B. s.n. (PACA34902); BR-116, 26 March 2017, Christ, A.L. 431 (ICN).

Figures

FIGURE 26: Distribution of C. ulei (triangles) and C. verbenacea (circles) in Rio Grande do Sul.

FIGURE 27: Chromolaena verbenacea. A. Fertile branch. B. Capitulum. C. Involucral bracts. D. Floret. E. Palea.

FIGURE 28A–B: Chromolaena squarrosoramosa. A. Primary capitulescence. B. General view. C–D: Chromolaena squarrulosa. C. Secondary capitulescence. D. Leaves. E–F: Chromolaena verbenacea. E. Secondary capitulescence. F. Leaves. Credits:Anderson Christ (A–C, E–F) and Sérgio Bordignon (D).