Drosera esmeraldae ( Steyermark 1952: 244 ) Maguire & Wurdack (1957: 335)

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 : 35-36

11. Drosera esmeraldae ( Steyermark 1952: 244) Maguire & Wurdack (1957: 335) . Figures 8b, 12 e, f

≡ Drosera tenella var. esmeraldae Steyermark (1952: 244)

Type: — VENEZUELA. Amazonas: between Esmeralda Savanna & SE base of Cerro Duida , 22 August 1944, Steyermark 57850 (holotype F-0055166!; isotypes NY-00328846!, US-00100653!, VEN-27435!) .

Perennial, rosetted, acaulescent or forming short columns densely covered by marcescent leaves. Leaves decumbent, with geniculate-involute vernation, distinctly petiolate, spatulate, petiole abruptly broadening into lamina, petiole about as long as to slightly longer than the lamina, lamina obovate to suborbicular; stipule rectangular in outline, divided into laciniate segments from the base. Scape erect at the base, glabrous, (30 –) 70 – 150 mm long, (2 –)4 – 12- flowered; pedicels about the same length as sepals or longer (always longer than half of the sepals’ length), 2 – 4(– 6) mm long; sepals 2.5 – 4.5 mm long, ovate, united up to half length, apex acute to cuspidate, glabrous or sparsely to densely glandular-pilose, mostly at the base, erect in fruit; petals white; gynoecium 3-carpelate, styles bifurcated at the base. Seeds ovoid, testa foveolate.

Illustrations: Duno de Stefano (1995: 84, figs. 2a–f); Duno de Stefano & Culham (1998: 701, fig. 555—habit and leaf).

Distribution: — Colombia, Venezuela, and Brazil (North: AM, RR; Fig. 8b). The species was only known from the north of the Rio Amazonas, but it is here first reported from the southern side, in the municipality of Novo Aripuanã (AM), however lacking georeferenced data [Ramos et al. s.n. (INPA-62135)].

Habitat: —Lowland wet savannas and highland rock outcrops in sandy soils or cracks of sandstone in wet areas, between 80 – 1700 m a.s.l.

Phenology:— Collected in flower in January, February, July and August.

Conservation status: —Least Concern (LC). Drosera esmeraldae is widespread in a relatively remote and preserved area ( Brazil: AOO= 32 km 2, EOO= 9,898 km 2; global: AOO= 104 km 2, EOO= 561,316 km 2). In Brazil it is found inside the Serra do Aracá State Park (AM).

Notes: — Drosera esmeraldae is more similar to D. capillaris , from which it is distinguished by longer pedicels relative to sepal length, sepals with acute to cuspidate apex, and seeds with foveolate testa (vs. pedicels shorter than the sepals, sepals with obtuse apex and seed with papillose testa; Table 3 ). It is also reminiscent of D. roraimae , being distinct from it by the smaller size, decumbent leaves (vs. semi-erect), scape base erect (Fig. 12e; vs. curved), and ovoid seeds with foveolate testa (vs. ellipsoid seeds with reticulate testa).

In contrast to the concept of Correa & Silva (2005) , which included D. esmeraldae under synonymy of D. biflora , we here consider these taxa distinct based on leaf, scape, sepal and seed morphology ( Table 3 ).

Hybridization and introgression between D. esmeraldae and D. roraimae are suspected to occur in places where both are syntopic, e.g. the Serra do Aracá, resulting in plants with intermediate features (such as the specimen Rivadavia et al. 784).

Specimens examined: — BRAZIL. Amazonas : Barcelos , Serra do Aracá , platô, 28 August 2011, Vicentini et al. 1899 ( INPA, MO); margin of Rio Aracá near Serrinha, 25 July 1985, Prance et al. 29800 ( INPA, MO, NY); alto da Serra do Aracá, 14 January 1999, Rivadavia et al. 784 ( SPF) ; Plateau of northern massif of Serra Aracá , South side of North Mountain, 12 February 1984, Prance et al. 28997 ( NY) ; Summit of Central Massif of Serra Aracá, 16 July 1985, Prance & Guedes 29604 (K, NY, US) . Nova Prainha [Novo Aripuanã], projeto Radam / Brasil, SB _20_XD, ponto 72 B, 13 July 1976, Ramos et al. s.n. (INPA-62135). Without attribution to administrative area, quadrante K6, na saída da trilha acampamento-campina, 03 September 1998, Vicentini et al. 1371 ( INPA, SPF) . Roraima : Rio Anauá , Catinga com Barcella, 30 April 1974, Pires et al. 14499 ( IAN) .