Commelina erecta 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 : 61-62

3. Commelina erecta L., Sp. Pl. 1: 41. 1753. Fig. 1C-D

Commelina erecta var. angustifolia (Michx.) Fern., Rhodora 42(503): 439.1940. Syn. nov.

Commelina virginica var. angustifolia (Michx.) C.B.Clarke, in De Candolle ALPP & De Candolle ACP Monogr. Phan. 3: 183. 1881. Syn. nov.

Commelina angustifolia Michx., Fl. Bor.-Amer. 1: 24. 1803. Holotype. USA. Sabulosis in Carolinae , s.dat., A. Michaux 100 (P barcode P00680427!). Syn. nov.

Eudipetala deficiens (Herb.) Raf., Fl. Tellur. 3: 68. 1837. Syn. nov.

Commelina deficiens Herb., Bot. Mag. 53: t. 2644. 1826. Lectotype (designated here). [illustration] Original parchment plate of “Curtis’s Botanical Magazine" at the Library of the Royal Horticultural Society, published in Hooker, Curtis’s Bot. Mag. 53: t. 2644. 1826. Syn. nov.

Commelina erecta f. villosa (C.B.Clarke) Stand. & Steyerm., Publ. Field Mus. Nat. Hist., Bot. Ser. 23(2): 33. 1944. Syn. nov.

Commelina villosa (C.B.Clarke) Chodat & Hassl., Bull. Herb. Boissier, sér. 2, 1: 438. 1901. Syn. nov.

Commelina virginica var. villosa C.B.Clarke, Monogr. Phan. 3: 183. 1881. Lectotype (designated here). BRAZIL. Rio Grande do Sul: "provincia de Rio Grande do Sul", 1816-1821, A. St.-Hilaire 2598 (P barcode P01742038!; isolectotype: P barcode P01742041!). Syn. nov.

Lectotype

(designated by Clarke 1881). " Commelina erecta , ampliore subcaeruleo flore " in Dillenius, Hort. Eltham. 1: 91, t. 77, f. 88. 1732.

Selected specimens seen.

BRAZIL. Rio de Janeiro: Araruama, 20 Apr 2008, A.C.S. Cavalcanti 139 (SPF). Armação de Búzios, loteamento de João Fernandes, quadra A, rua I, lote 10, 27 Jul 2013, M. Furtado 28 (RB). Arraial do Cabo, Praia do Pontal, 31 Jul 1953, F. Segadas Vianna s.n. (US barcode US 2283943.2455262). Cabo Frio, Peró, Sítio Guriri, 21 Jul 2003, G.S.Z. Rezende 191 (RB). Campos dos Goytacazes, Feb 1918, A.J. Sampaio 2813 (R). Carapebus, 23 Mar 1996, V. Esteves 947 (R). Macaé, Parque Nacional da Restinga de Jurubatiba, margem da estrada principal, entre a praia e as moitas, próximo a Lagoa Cabiúnas, 23 Jun 2013, L.S.B. Calazans 219 (RB). Mangaratiba, Ilha da Marambaia, Praia Grande, 15 Jan 1986, E.M. Occhioni 484 (RB). Maricá, 16 Feb 2005, A.T.A. Rodarte 195 (RB). Niterói, Parque Estadual da Serra da Tiririca, Pedra de Itacoatiara, 16 Feb 2000, M.C.F. Santos 496 (RB, RFFP). Paraty, Parati Mirim, Fazenda Parati-Mirim, propriedade da Flumitur, s.dat., C. Almeida 1931 (RB). Rio de Janeiro, Urca, 10 Jan 2012, M.O.O. Pellegrini et al. 181 (RB). Santo Antônio de Pádua, Monte Alegre, Mar 1927, J. Vidal s.n. (R 205994). São Gonçalo, Paraíso, Faculdade Formação de Professores da Universidade do Estado do Rio de Janeiro, 20 Oct 2006, N. Coqueiro 297 (RB, RFFP). São João da Barra, Restinga de Iquipari, 11 Dec 2002, M.C. Gaglione 8 (RB). Saquarema, 21 Feb 1996, A.Q. Lobão 76 (RB).

Distribution and habitat.

Tropical and subtropical regions of the world, being common in disturbed areas of drier regions inland or near the coast, commonly found in restingas or in urban areas (Fig. 2 ).

Phenology.

Throughout the year, but especially in the rainy season.

Conservation status.

Following the IUCN recommendations ( IUCN 2001), it should be considered as Least Concern (LC) in the state of the Rio de Janeiro and worldwide.

Nomenclatural and taxonomical notes.

Clarke (1881), in his revision of Commelinaceae , erroneously considered C. erecta as a synonym of C. virginica L., a species endemic to the USA ( Faden 2000). Thus, some names currently placed under the synonymy of C. erecta were originally described under C. virginica , or transferred to it at some point. According to Faden (1993, 2000), Commelina erecta can be differentiated by its leaf-sheaths with auriculate margins, medial petal linear and hyaline, and all locules 1-seeded (vs. leaf-sheaths not auriculate, medial petal blue and conspicuous, and dorsal locule 1-seeded and ventral locules 2-seeded, in C. virginica ).

There seems to be some doubt regarding C. deficiens Herb. synonymy. According to Tropicos.org ( 2015), this species is considered a synonym of C. erecta . Nevertheless, eMonocot.org (2010) and The Plant List (2013) treat C. deficiens under the synonymy of C. virginica . As abovementioned, there is an historical confusion regarding C. erecta and C. virginica . If we exclusively take into account that C. deficiens was described by Herbert (1826) from the surrounding areas of Rio de Janeiro, it is impossible for C. deficiens to be conspecific to C. virginica . Added to that, the watercolour presented by the author perfectly illustrates the habit, flower morphology and the inflorescence characteristic of C. erecta (with the aborted upper cincinnus). Thus, there is little doubt that C. deficiens is a synonym of the latter. According to Stafleu and Cowan (1979), Herbert’s type specimens were deposited at K, but no specimen corresponding to C. deficiens was found. Thus, in accordance to the Code ( McNeill et al. 2012, Art. 9.12), in the absence of herbarium specimens, we designate this illustration as the lectotype for C. deficiens .

Commelina villosa (C.B.Clarke) Chodat & Hassl. has long been a name of dubious application. Clarke (1881) had already noticed that its morphological concept overlapped with the one of the highly variable C. erecta , and that the difference between them relied solely on the plant’s indumenta. The observation of a great number of natural populations and specimens kept in greenhouses showed that most of the morphological variation known for C. erecta has an environmental background. Large flowered specimens developed into small flowered specimens after being transplanted from sunny to shady areas. The same thing happened to narrow-leafed and erect plants (which would represent C. erecta var. angustifolia ), developing into creeping and small to wide-leafed plants. The indumenta also varied when specimens were transplanted from the field to the greenhouse. Regarding growth form and position of the stem of C. erecta , the plants can vary from creeping to sub-scandent (i.e. stems leaning generally on bushes or any other kind of support) to partially or completely erect. The only morphological characters, constant in all areas and environmental conditions were: the auriculate leaf-sheath margins; terminal to apparently terminal inflorescences (1-3 per stem), broadly sagittate to subcordate spathes with connate margin, aborted upper cincinnus (generally completely absent, but sometimes only vestigial); hyaline, linear and involute medial petal (almost invisible at blind sight); capsules with 1-seeded locules; and smooth seed testa.

After analyzing the original descriptions and the type specimens, it became clear that C. villosa and C. erecta var. angustifolia are conspecific to C. erecta . Thus, no varieties or subspecies are accepted in Brazil for C. erecta .

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.