Pteris cadieri, Christ, 1905

Chao, Yi-Shan, Liu, Ho-Yih & Chiou, Wen-Liang, 2015, Taxonomic revision of the Pteris cadieri complex (Pteridaceae), Phytotaxa 230 (2), pp. 130-150 : 149

Key to the Pteris cadieri complex

1. Sterile laminae pinnate.......................................................................................................................................................................2

- Sterile lamina bipinnatifid ..................................................................................................................................................................5

2. Most sterile laminae with two or more pairs of lateral pinnae; terminal pinna at least 1.5 times longer than lateral pinnae; pinna apex acute to obtuse. ............................................................................................................................................................................. ................................................................................................................................................................ P. dimorpha var. prolongata

- Most sterile laminae with one pair of lateral pinnae, all pinnae nearly equal in length; pinna apex acuminate to caudate...............3

3. Sterile laminae with incurved basal pinnae ....................................................................................................................... P. perplexa

- Sterile laminae with straight basal pinnae..........................................................................................................................................4

4. Fertile pinnae simple, 0.5–1.2 cm wide................................................................................................................................ P. cadieri

- Fertile pinnae with digital projections, 1–4 cm wide ................................................................................................... P. hainanensis

5. Fertile laminae bipinnatifid ................................................................................................................................................................6

- Fertile laminae not bipinnatifid ..........................................................................................................................................................8

6. Fertile laminae irregularly bipinnatifid; sinuses 3–6 mm wide in fertile laminae ......................... P. dimorpha var. metagrevilleana

- Fertile laminae regularly bipinnatifid; sinuses 1–2 mm wide in fertile laminae................................................................................7

7. Pinnae green throughout...................................................................................................................... P. grevilleana var. grevilleana

- Pinnae with broad, white, central stripe ......................................................................................................... P. grevilleana f. ornata

8. Sterile laminae with straight basal pinnae ................................................................................................ P. dimorpha var. dimorpha

- Sterile laminae with incurved basal pinnae........................................................................................................................................9

9. Sterile laminae all bipinnatifid ......................................................................................................................................... P. incurvata

- Sterile laminae pinnate, with digital projections, or bipinnatifid ...................................................................................... P. perplexa