Drosera grantsaui Rivadavia (2003: 82)

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 : 37-39

13. Drosera grantsaui Rivadavia (2003: 82) . Figures 4e, 13a–c

Type: — BRAZIL. Minas Gerais: Grão Mogol, morro do Jambeiro, nascente brejosa na base do morro, c. 7 km da cidade pela estrada para Montes Claros , 700 m alt., 08 September 1994, Rivadavia 299 (holotype SPF-156000!; isotypes K-001204974!, MBM!) .

Perennial, caulescent, stem delicate, usually conspicuous, erect or supported by surrounding vegetation, 1–28 cm long, with conspicuous internodes. Leaves semi-erect, with circinate vernation, petiole distinct, narrower than lamina and about the same length, lamina oblong to narrowly oblong-spatulate; stipules rectangular, upper half divided into several laciniae. Scape with erect base, delicate, glabrescent; sepals glandular-pilose; petals white to light pink; gynoecium 3-carpelate, styles bifurcated at the base. Seeds fusiform, testa reticulate, pale brown.

Illustrations:— Silva (1994: 82, fig. 15N—leaf as Drosera communis ); Rivadavia (2003: 80, fig. 2—habit and details).

Distribution:— Brazil (North:TO; Northeast:BA; Central-West: DF, GO, MS, MT; Southeast: MG, SP; South: PR, SC; Fig. 4e) and Paraguay (Caaguazú). It is here first recorded from Santa Catarina, which represents the southernmost known record of the species.

Habitat: —Perennially moist to wet grasslands (sometimes growing temporarily submerged) in sandy to peaty soils of the Cerrado and Mata Atlântica domains. It occurs in marginal areas of veredas, and along river margins, usually among tall and somewhat dense grasses and sedges, but also in more open areas. In the campos rupestres (BA, GO, and MG) and in the campos gerais (PR and SC) vegetation types, the species grows in and around perennially wet springs in sandy to peaty soil, occasionally in carpets of Sphagnum . Occurs between 600–1600 m a.s.l.

Phenology:— Drosera grantsaui seems to have no defined flowering season, being found with flowers and fruit year-round. However, a flowering peak can be observed at the end of the dry season, between August and November, as reported by Rivadavia (2003).

Conservation status:—Least Concern (LC). Drosera grantsaui is widely distributed and found in several protected areas across its range ( Brazil:AOO= 172 km 2, EOO= 1,417,756 km 2; global:AOO= 176 km 2, EOO= 1,677,552 km 2). It is known from the National Parks of Serra do Cipó (MG), Sempre-Vivas (MG), Serra da Canastra (MG), Emas (GO), and Chapada dos Veadeiros (GO), and in the State Parks of Botumirim, Grão Mogol, and Rio Preto, all in Minas Gerais.

Notes: — Drosera grantsaui is unique as it presents a delicate caulescent habit (Fig. 13a, b), leaves with circinate vernation and with oblong to oblong-spatulate lamina, stipules rectangular with the upper half divided in laciniate segments, glabrescent scapes with erect base (Fig. 13b), and fusiform seeds. Specimens of this taxon were previously identified as D. communis (e.g. Diels 1906, Silva & Giulietti 1998, Correa & Silva 2005 ), probably due to its delicate habit, which favors negligence of important diagnostic characters. Nevertheless, these two taxa are very distinct and only distantly related, belonging even to different sections (Table 1).

Although Rivadavia (2003)presented a very complete treatment and discussion distinguishing it from D. communis , D. grantsaui was placed under synonymy of D. communis by Silva (2007) , with the argument that no differences could be observed between them. Further investigations revealed that the two species are not closely related, as supported by the distinctive leaf vernation, chromosome number ( Rivadavia 2005) and molecular data ( Gonella 2017), which place these two taxa in different sections ( Fleischmann et al. 2018b). The distinctive characters between the two taxa are presented in Table 4.

Drosera grantsaui often hybridizes with D. tomentosa in areas where both species are sympatric and syntopic, forming the hybrid D. × fontinalis Rivadavia (2009: 121; more under this nothotaxon below).

Specimens examined: —For an extensive listing, see Rivadavia (2003: 84–85).

Additional specimens examined: — BRAZIL. Locality not indicated: Sellow 128 (B). Bahia: Piatã , alto da serra, 29 April 2010, Gonella & Fleischmann 331 ( SPF) . Distrito Federal: Brasília, Parque Municipal do Gama , 03 September 1964, Irwin & Soderstrom 5900 (MO, NY, UB). Goiás: Alto Paraíso de Goiás, Chapada dos Veadeiros, 23 June 2007, Rivadavia & Batista 2624 ( SPF) . Entre Rio Torto e Paranana, 1896, Glaziou 21121 (K). Mato Grosso: Chapada dos Guimarães, 29 April, 1995, Rivadavia & Cardoso 422 ( SPF) . Vila Bela da Santíssima Trindade, Chapada dos Parecis, 27 July 1986, Emmerich et al. 6044 (R). Mato Grosso do Sul: Costa Rica , salto da Rapadura, 28 October 2001, Rivadavia 1300 ( SPF) . Minas Gerais: Diamantina, estrada para a Gruta do Salitre , 13 May 2007, Rivadavia 2539 ( SPF) . Itacambira, km 91 da estrada para Montes Claros , 22 April 2010, Gonella et al. 289 ( SPF) . Joaquim Felício, estrada da ‘ Serra do Cabral Agro Indústria S.A. ’ entre Joaquim Felício e Francisco Dumont , 03 July 2003, Rivadavia 1665 ( SPF) . São Roque de Minas, Parque Nacional da Serra da Canastra , 21 November 2002, Pacheco et al. 423 ( HUFU) . Paraná: Jaguariaíva, estrada Ponta Grossa-Sengés (PR-151), Rio Cajurú , 24 April 1995, Rivadavia 410 ( SPF) . Santa Catarina: Campo Alegre, Serra do Quiriri , 20 May 2016, Dolsan 43 ( RB) . São Paulo: Itararé, estrada Itararé-Itapeva (SP-258), Rio Verde , 24 April 1995, Rivadavia 418 ( SPF) . São Paulo, Butantan , 03 October 1917, Hoehne 660 ( SP) . Tocantins: Ponte Alta, Jalapão , 17 June 2006, Rivadavia 2262 ( SPF) .