Drosera graminifolia Saint-Hilaire (1826: 269)

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 : 36-37

12. Drosera graminifolia Saint-Hilaire (1826: 269) . Figures 6d, 12g –i

Type: — BRAZIL. Minas Gerais: au sommet de la Serra de Caraça, dans la province des Mines [on the summit of the Serra do Caraça, Minas Gerais], February 1817, Saint-Hilaire B 1-448 (holotype P-00749154!) .

= Drosera graminifolia var. major Eichler in Martius & Eichler (1872: 396).

Type: — BRAZIL. Minas Gerais: Serra do Caraça , December 1830, Sellow 1300 (holotype B-100000156!; isotype K-000432556!) .

Perennial, rosetted, acaulescent or forming columns up to 6(–15) cm long, internodes very short. Glandular trichomes of the TSG type and eglandular trichomes present on leaves, scapes, pedicels and sepals. Leaves erect to semi-erect, with regular circinate vernation, linear, petioles 30–45(–50) × 1.5–2.4 mm; stipules 7–14 × 6.5–10.0 mm, triangular, golden-brown in color; stipules triangular, 7–14 mm long, apex fimbriate. Petals pink; gynoecium 3-carpelate, styles bifurcated at the base. Seeds oblong-fusiform 0.65–0.80 × 0.2 mm, testa reticulate (based on Gonella et al. 2012).

Illustrations:— Saint-Hilaire (1826: t. XXV, figs. C & 2—habit and stipule); Gonella et al. (2012: 46, fig. 2—habit and details).

Distribution:— Brazil (Southeast: MG), endemic (Fig. 6d). Restricted to high-montane areas around the summits of the four tallest peaks of the Serra do Caraça (Canjerana, Carapuça, Inficcionado, and Sol), in the southern portion of the Espinhaço Range in Minas Gerais. Found at elevations of 1700–1950 m.

Habitat: —Sandy-peaty substrate or islands of vegetation (sometimes also in Sphagnum carpets) in shallow, wet to moist soils overlying sandstone escarpments in high-montane areas, in campo rupestre vegetation. Found between 1700–1950 m a.s.l.

Phenology:— Found in flower between January to April, with a second minor flowering period in September.

Conservation status:—Critically Endangered (CR) B1ab(iii)c(iv). Gonella et al. (2012) designated this species CR based on the restricted occurrence (AOO= 16 km 2; EOO= 17.6 km 2) limited to a single location (Serra do Caraça highlands), the observed decline in the known populations during the last decades probably due to air pollution from mining activities around the Serra do Caraça, and also the threat of invasive grasses in the very fragile highland habitats occupied by this species. These habitats are also very susceptible to dramatic reductions in climatic suitability over the next decades due to climate change. Found inside the private protection area of the RPPN Santuário do Caraça.

Notes: — Drosera graminifolia is most similar to D. spiralis , from which it is distinguished by the indumentum, such as the presence of TSG trichomes (vs. short capitate trichomes) and longer eglandular trichomes on leaves (3–5 mm vs. 0.5–1.5 mm), leaves with regular circinate vernation (vs. irregular circinate), shorther stipules [7–14 mm vs. 14–22(–30) mm], longer petioles (30–50 mm vs. 5–30 mm) that are much longer than the stipules, and oblong-fusiform seeds (vs. ovoid).

The species was re-circumscribed by Gonella et al. (2012), which also re-established D. spiralis from its synonymy. Besides the very clear morphological distinction, both species differ in habitat preferences and area of distribution (see Gonella et al. 2012). Drosera graminifolia is also comparable (and likely closely related) to D. magnifica ( Gonella et al. 2015) , but that species differs significantly in several morphological aspects (see under D. magnifica ).

Drosera graminifolia var. major was described based on the specimen Sellow 1300 deposited at B, as indicated in an annotation by Eichler on the specimen’s label. An isotype duplicate of that specimen was found at K, yet without any indication to the variety name .

Specimens examined: —For an extensive listing, see Gonella et al. (2012: 49).

Additional specimens examined: — BRAZIL. Minas Gerais: Santa Bárbara, Parque Natural do Caraça , 05 March 1992, Rivadavia 122 (K, SPF). “Environs de Rio de Janeiro et d’Ouro Preto” [Glaziou’s locality data is frequently unreliable or even wrong, see e.g. Wurdack 1970], 1883-84, Glaziou 14485 (K).