Drosera species

Rivadavia, Fernando, Gonella, Paulo Minatel, Sano, Paulo Takeo & Fleischmann, Andreas, 2014, Elucidating the controversial Drosera montana complex (Droseraceae): a taxonomic revision, Phytotaxa 172 (3), pp. 141-175 : 146

Key to the Drosera species with decumbent leaves from Brazil south of the Equator (with extensions in South America south of the Equator given in brackets)

1. Gynoecium 5-merous, styles 5, undivided; leaves with glandular trichomes only (in addition to tentacles and sessile glands) [also in Bolivia] ...................................................................................................................................................................... D. sessilifolia

- Gynoecium 3-merous, styles 3, bifurcated at the base (6 stigmata in total); leaves glabrous, or with eglandular trichomes only, or with both glandular and eglandular trichomes (in addition to tentacles and sessile glands)..............................................................2

2. Stipules absent or reduced to few fimbriae isolated on the margins of the leaf base [also in Argentina and Uruguay] D. brevifolia

- Stipules well developed, conspicuous, intrapetiolar...........................................................................................................................3

3. Lamina with apex narrower or of similar width than the base (oblong, lanceolate, or ellipsoid in outline) .....................................4

- Lamina with apex distinctly broader than the base (obovate, oblanceolate, spatulate, cuneate, or sub-orbicular in outline) ..........5

4. Leaves oblong, petiole usually ≤ 0.5 mm wide (rarely up to 1 mm wide); glandular trichomes densely covering the scapes from the base; seeds ovoid to ellipsoid [also in Bolivia] ................................................................................................................ D. montana

- Leaves oblong-lanceolate to lanceolate, usually semi-erect, petiole ≥ 1 mm wide; glandular trichomes absent on the basal third of the scape; seeds fusiform.................................................................................................................................................... D. latifolia

5. Scape erect at the base .......................................................................................................................................................................6

- Scape arcuatelly curved at the base..................................................................................................................................................13

6. Petiole narrow, suddenly broadening into lamina; petiole longer or equal in length with the lamina; leaf vernation geniculateinvolute...............................................................................................................................................................................................7

- Petiole gradually broadening into lamina; petiole length equal to or shorter than half lamina length; leaf vernation geniculate or circinate .............................................................................................................................................................................................9

7. Sepals glabrous; seeds with papillose testa [also in Uruguay] ........................................................................................ D. capillaris

- Sepals glandular- and/or eglandular-pilose; seeds with foveolate or reticulate testa .........................................................................8

8. Scapes glabrous; sepals exclusively glandular-pilose; seeds rectangular with reticulate testa ............................................. D. viridis

- Scapes pilose; sepals exclusively eglandular-pilose, or both glandular- and eglandular-pilose; seeds ovoid with foveolate testa [also in Bolivia and Peru]..................................................................................................................................................... D. cayennensis

9. Leaf obovate-cuneate to cuneate with geniculate vernation; apical tentacles conspicuously distinct, in number of 7–12, 4– 9 mm long, with head with unifacial gland tip ........................................................................................................................ D. tentaculata

- Leaf obovate, oblanceolate, or oblong-spatulate with circinate vernation; apical tentacles inconspicuously distinct, only up to 5 mm long............................................................................................................................................................................................10

10. Adaxial petiole surface densely eglandular-pilose; sepals ovate to sub-orbicular with rounded (subobtuse) apex, in bud forming a pyramidal projection at the fusion point between adjacent sepals ................................................................................. D. spirocalyx

- Adaxial petiole surface glabrous or sparsely eglandular-pilose; sepals oblong-ovate to narrowly-ovate with acute apex, not forming pyramidal projections as described above........................................................................................................................................11

11. Leaves oblong to oblong-spatulate; petiole 0.2–0.5(–1) mm wide; glandular trichomes of similar length present throughout scape; generally flowering from December to March (rainy season) [also in Bolivia] ............................................................... D. montana

- Leaves obovate to oblong-obovate; petiole 0.4–3.0 mm wide; glandular trichomes absent on the basal third of scape, but dense and larger towards the apex; generally flowering from June to September (dry season) .............................................. D. tomentosa (12)

12. Scapes densely eglandular-pilose (villous) on the basal half, decreasing in density towards apex ....... D. tomentosa var. tomentosa

- Scapes exclusively glandular-pilose from base to apex, without notable eglandular indumentum, occasionally also sparsely eglandular-pilose mostly towards the basal third ...................................................................................... D. tomentosa var. glabrata

13. Basal third of scape densely eglandular-pilose............................................................................................................ D. hirtella (14)

- Basal third of scape glabrous to glabrescent ....................................................................................................................................15

14. Lamina obovate; scape green to red; eglandular trichomes of scape red........................................................ D. hirtella var. hirtella

- Lamina spatulate; scape yellow; eglandular trichomes of scape white [also in Bolivia] ............................. D. hirtella var. lutescens

15. Leaves decumbent, entirely green or with pinkish-red petiole and green lamina (even if growing in sunny habitats); seeds rectangular ............................................................................................................................................................................. D. viridis

- Leaves usually semi-erect, red (greener only in shaded habitats); seeds fusiform [also in Bolivia, Paraguay, and Argentina] .......... ......................................................................................................................................................................................... D. communis