Adiantum species (Huiet, 2018)

Cádiz-Véliz, Arón, Palma-Villalobos, Bárbara, Villarroel, Alejandro E. & Muñoz-Schick, Mélica, 2023, Adiantum viscosum (Pteridaceae), a new species endemic to sclerophyllous forest of Central Chile, Phytotaxa 599 (3), pp. 183-192 : 189-190

Identification key to Adiantum species in Chile, modified from Rodríguez (1995, 2015) and Sundue et al. (2010)

1. Pinnules glabrous................................................................................................................................................................................2

- Pinnules not glabrous .........................................................................................................................................................................5

2. Blades 1 pinnate .................................................................................................................................................................. A. pearcei

- Blades 2–3 pinnate .............................................................................................................................................................................3

3. Veins sparse (≤4), spaced, conspicuous; rachises with septate trichomes and narrow scales up to 2 mm long; blades herbaceous ... ............................................................................................................................................................................................ A. excisum

- Veins numerous (>4), approximate, inconspicuous; rachises glabrous; blades coriaceous ...............................................................4

4. Apical pinnules cuneate-flabellate; veins ending in the center of a tooth.............................................................. A. capillus-veneris

- Apical pinnules subtrapezoidal or reniform; veins ending between two teeth................................................................... A. chilense

5. Blades with simple or glandular trichomes ........................................................................................................................................6 - Blades with glomerular trichomes (mealy texture) ............................................................................................................................8

6. Blades with simple, non-glandular trichomes, without sticky or aromatic resin ...............................................................................7

- Blades with capitate and glandular trichomes, producing sticky and aromatic resin........................................................ A. viscosum

7. Blades with trichomes ≤ 1 mm long; pinnae subtrapezoidal to reniform................................................................... A. glanduliferum

- Blades with trichomes 1–1.5 mm long; pinnae rhomboidal.............................................................................................. A. gertrudis

8. Pinnules covered with white glomerular trichomes .......................................................................................................... A. scabrum

- Pinnules covered with yellow glomerular trichomes .........................................................................................................................9

9. Glomerular trichomes rounded........................................................................................................... A. sulphureum var. sulphureum

- Glomerular trichomes elongated ................................................................................................................. A. sulphureum var. majus