Commelina benghalensis L., Sp. Pl. 1: 41. 1753

Pellegrini, Marco Octavio de Oliveira & Forzza, Rafaela Campostrini, 2017, Synopsis of Commelina L. (Commelinaceae) in the state of Rio de Janeiro, reveals a new white-flowered species endemic to Brazil, PhytoKeys 78, pp. 59-81 : 60

1. Commelina benghalensis L., Sp. Pl. 1: 41. 1753 nom. cons. Fig. 1A

Neotype

(conserved and designated by Faden 1992). INDIA. Habitat in Benghala, s.dat., s.leg., Herb. Linn. 65.16 (LINN!).

Selected specimens seen.

BRAZIL. Rio de Janeiro: Angra dos Reis, Ilha Grande, matas da praia de Abraão, 18 Apr 1987, L.C. Giordano 277 (RB). Armação de Búzios, 19 Aug 1998, D. Fernandes 19 (R). Cabo Frio, 22 Oct 2013, H.F. Uller s.n. (RB 612224). Campos dos Goytacazes, Morro do Itaoca, Pedra Negra ponto 1, 13 Oct 2009, L.P. Mauad & I.O.R. Areias 20 (RB). Casimiro de Abreu, Praião, Avenida Oceânica, 24 Jun 2012, A.J. Castelo 39 (RB). Iguaba Grande, Km 94, 1981, H. Barreto s.n. (RB 275353). Macaé, Córrego de Ouro, Fazenda Vitória, Morro do Oratório, 2 May 1971, J.P.P. Carauta 1364 (RB, U n.v.). Niterói, Itaipuaçu, próximo ao Canal da Costa, 18 Sep 2004, T.T. Carrijo 143 (RB). Resende, margem da rodovia Dutra, Km 302 sentido RJ, ao lado da Light, próximo ao Rio Paraíba do Sul, 9 Jun 2012, M.O.O. Pellegrini et al. 233 (RB). Rio de Janeiro, Morro do Rangel, Recreio dos Bandeirantes, 31 May 1973, D. Sucre 10005 (RB, US). São José de Ubá, 14 May 2014, T.M. Scarponi s.n. (RB 612228). Saquarema, Tingui em Sampaio Correia, 14 Apr 1995, J.A. Lira Neto 56 (RB). Silva Jardim, Próximo a sede da REBIO, 29 Oct 1997, J.A. Lira Neto 719 (RB).

Distribution and habitat.

Tropical and subtropical regions of the world. In the state of Rio de Janeiro it is especially common in disturbed areas of drier regions inland or near the coast, being common in restingas (i.e. sandbank vegetation), and as a weed in agricultural fields (Fig. 2 ).

Phenology.

Throughout the year, but especially in the rainy season.

Conservation status.

It is a weed of worldwide distribution being very common in sunny disturbed areas and in agricultural fields. Following the IUCN recommendations ( IUCN 2001), it should be considered as Least Concern (LC) in the state of Rio de Janeiro and worldwide.

Morphological and ecological notes.

The underground cleistogamous flowers and fruits seem to be produced only in areas where the soil is soft. The flower morphology differs from the aerial chasmogamous in pigmentation (being paler), while the fruits are sub-globose (due to larger seeds).

Figures

Figure 1. Commelina in the state of Rio de Janeiro. A C. benghalensis L. B C. diffusa Burm. f. C-D C. erecta L.: C detail of the inflorescence showing aborted upper cincinnus D flower E-F C. obliqua Vahl: E detail of the inflorescence showing the two developed cincinni F flower G C. rufipes var. glabrata (D. R. Hunt) Faden & D. R. Hunt H-I C. rufipes var. rufipes Seub.: H detail of the leaf-sheaths, showing the hirsute rusty hairs I mature fruits. G by Flora Virtual Estacion Biologica El Verde group, remaining field photos by M. O. O. Pellegrini.

Figure 2. Distribution map of Commelina in the state of Rio de Janeiro. Crosses C. benghalensis green dots C. diffusa var. diffusa; blue dots C. erecta; stars C. obliqua; empty square C. rufipes var. glabrata; full squares C. rufipes var. rufipes.