Drosera quartzicola Rivadavia & Gonella (2011: 34)

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 : 53-54

22. Drosera quartzicola Rivadavia & Gonella (2011: 34) . Figures 6a,19d–f

Type: — BRAZIL. Minas Gerais: Santana do Riacho, km 112-113 da estrada para Conceição do Mato Dentro (MG-10), em morro após bifurcação da trilha para o Travessão e cachoeira Congonhas , seguindo à esquerda, 1360 m, 19 April 2010, Gonella et al. 264 (holotype SPF-203300!) .

Perennial, rosetted, acaulescent or forming short columns up to 40 mm tall. Glandular trichomes of TSG type present on both leaf surfaces, scapes, pedicels and sepals. Leaves semi-erect, with circinate vernation, lanceolate, petioles about as long and as wide as the lamina and lacking eglandular trichomes in the adaxial surface, abaxial leaf surface densely eglandular-pilose; stipules triangular, 6–8 mm long, golden-brown. Scapes short, base erect, 17–115 mm long; petals pink; gynoecium 3-carpelate, styles bifurcated at the base. Seeds narrowly oblong-ovate, 0.7–0.8 mm long, testa reticulate, black (based on Rivadavia & Gonella 2011).

Illustrations: — Rivadavia & Gonella (2011: 35, fig. 1—habit and details).

Distribution: — Brazil (Southeast: MG), endemic to the central portion of Serra do Cipó, in central Minas Gerais (Fig. 6a).

Habitat: —Relatively dry areas of campo rupestre vegetation, in fine silica sand mixed with white quartz gravel. Found at elevations between 1100–1360 m.

Phenology:— Found in flower from November to April.

Conservation status: —Critically Endangered (CR) B1ab(iii, iv). Rivadavia & Gonella (2011) designated this species as CR based on its restricted occurrence, fragile habitat, and small number of sub-populations. Only four subpopulations were known at the time of publication (containing 20, 60, 100, and 120 individuals respectively; Rivadavia & Gonella 2011), with two additional having been discovered since, both with ca. 20 adult individuals. This brings the total known population size of D. quartzicola to ca. 340 individuals.

Despite the discovery of new populations, the species remains very restricted (EOO= 9.1 km 2, AOO= 12 km 2), with each population containing a reduced number of individuals spread over a very limited area of a few m 2 each, making them very susceptible to stochastic events. The species is further threatened by drastic reduction of habitat quality due to anthropogenic fires, invasive grasses, and climate change. Of the six known populations, two are found inside the Serra do Cipó National Park, and the remaining four in the Environmental Protection Area (APA) Morro da Pedreira.

Notes: — Drosera quartzicola is most similar to D. chrysolepis , with which it is syntopic at one location where infrequent hybrids are also found (see ‘Natural Hybrids’ below; Rivadavia & Gonella 2011). It can be distinguished by the acaulescent or column-forming habit (Fig. 19d, e; vs. caulescent), petioles about as wide as the lamina (Fig. 19e; vs. petiole 2-3 times narrower than the lamina), and shorter inflorescences (Fig. 19d).

Specimens examined: —For an extensive listing, see Rivadavia & Gonella (2011: 39).

Additional specimens examined: — BRAZIL. Minas Gerais: Santana do Riacho, Serra do Cipó, km 114 da MG-10, trilha para o Canyon do Travessão , 10 November 2013, Gonella et al. 633 ( SPF, BHCB, RB); APA Morro da Pedreira , km 110 da MG-10, 06 July 2014, Gonella & Rohrbacher 669 ( SPF) , 670 (SPF).