Drosera viridis Rivadavia (2003: 87)

Gonella, Paulo Minatel, Sano, Paulo Takeo, Rivadavia, Fernando & Fleischmann, Andreas, 2022, A synopsis of the genus Drosera (Droseraceae) in Brazil, Phytotaxa 553 (1), pp. 1-76 : 64-65

32. Drosera viridis Rivadavia (2003: 87) . Figures 7f, 22g –i

Type: — BRAZIL. São Paulo: [Santo André], Paranapiacaba, estrada de terra para Paranapiacaba , paralela aos trilhos do trem, c. 2 km antes da cidade, 02 February 1996, Rivadavia-Lopes & Cardoso 510 (holotype SPF-158000!, isotypes MBM-287295!, NY-00688466!, R-210202!) .

Perennial, rosetted, acaulescent. Leaves decumbent, with geniculate-involute vernation, distinctly petiolate, spatulate, entirely green or with reddish base and green apex; lamina obovate to suborbicular, tentacles with translucent stalk and red head; stipule rectangular in outline, divided into multiple laciniate segments from the base. Scapes erect to slightly arcuate at the base, base glabrous, apex, pedicels and sepals glandular-pilose; petals light pink; gynoecium 3-carpelate, styles bifurcated at the base. Seeds rectangular, testa reticulate.

Illustrations: —Rivadavia (2003: 89, figs. 4.1A-E; 4.2F, G—habit and details [figure captions in the original description had been switched for figs. 4.1F,G and 4.2F,G]).

Distribution: — Brazil (Southeast: SP; South: PR, RS, SC), endemic (Fig. 7f). Recently first reported from Rio Grande do Sul, representing the southernmost record for the species ( Gonella & Lehn 2020).

Habitat: —Found in perennially humid to waterlogged habitats along stream sides and in seepages, usually in red to white clayish soils, but also in sandy soils, at elevations between 500–1340 m, often among rather tall marsh vegetation. Although the typical habitat constitutes campos de altitude and campos gerais, D. viridis also occurs as a ruderal in disturbed areas within its range, on banks along roadsides or railways in upland areas that receive year-round condensation from fog.

Phenology: — Drosera viridis presents a flowering peak between December and March, but individuals with flowers can be observed year-round.

Conservation status: —Near Threatened (NT), per Gonella & Lehn (2020).Although relatively widely distributed in four Brazilian states, D. viridis occupies very specific and fragile habitats and may face increased risk of extinction in the near future. As an example, the type locality (a ditch along a dirt road) was revisited in 2011 and no plants were found, suggesting it may have become locally extinct. The calculated EOO of 159,234 km 2 qualifies this species as LC, while the AOO of 88 km 2 qualifies it as EN. The Atlantic Rainforest grasslands where this species occurs have undergone a drastic reduction in the last decades for agriculture and livestock activities, further aggravated by the introduction of exotic grasses. Gonella & Lehn (2020) report it from the Aparados da Serra National Park (RS) and Vila Velha State Park (PR).

Notes: — Drosera viridis is closely allied to D. communis , with which it often occurs sympatrically and syntopically. Although no hybrids have ever been confirmed, this has not been excluded as a possibility. When the two species grow syntopically (e.g. Fig. 22g), D. viridis is easily distinguished by overall larger size, greenish leaves bearing tentacles with a translucent stalk and red glandular head (Fig. 22h; vs. reddish leaves,tentacles entirely red), less evident curvature of the scape, and rectangular seed shape (vs. fusiform). Furthermore, they can be distinguished by leaf indumentum: D. viridis presents eglandular trichomes exclusively on the petiole margins, while syntopic D. communis also presents such trichomes on both abaxial and adaxial surfaces (it is important to notice, however, that D. communis is variable for this character along its broader range). Although usually easily identifiable in the living state, D. viridis is not very easy to distinguish from D. communis in dried specimens, since most of the cited differences are lost during herborization.

Specimens examined: —For an extensive listing, see Rivadavia (2003: 88–89).

Representative specimens examined: — BRAZIL. São Paulo: Embu Guaçu, distrito de Cipó , 11 February 2006, Rivadavia & Miranda 2143 ( SPF) . Paraná: Campo Largo, Serra de São Luís, próximo a São Luís do Purunã , 25 November 2006, Rivadavia & Rohrbacher 2443 ( SPF) . Palmeira, Rio das Pombas , 25 November 2006, Rivadavia & Rohrbacher 2448 ( SPF) . Rio Grande do Sul: Cambará do Sul, Fortaleza , 27 September 1992, Barbieri s.n. (HUCS 12638a; mixed collection with D. brevifolia ). São José dos Ausentes, Canyon Montenegro, 27 December 2019, Lehn 2566 (HUCS, SPF) . Santa Catarina: Campo Alegre, Campos do Quiriri , 17 November 2012, Silva 24 ( JPB) . Mafra, campo São Lourenço , 18 January 2014, Antunes Filho 1 ( SPF) . Santa Cecília, Serra do Espigão , 22 February 2014, Antunes Filho 2 ( SPF) .