Pteris

Kessler, Michael, Smith, Alan R. & Prado, Jefferson, 2017, Prodromus of a fern flora for Bolivia. XXVII. Pteridaceae, Phytotaxa 332 (3), pp. 201-250 : 225-226

Key to the Bolivian species of Pteris

1 Blades 1-pinnate (rarely 2-pinnate at base) and with venation areolate or blades pinnate and with the proximal pinna-pair furcate (basiscopic portion elongate) and with venation free ....................................................................................................................... 2

- Blades usually 1-or 2-pinnate-pinnatifid (rarely 3-pinnate-pinnatifid at base), proximal pinna-pair furcate (basiscopic portion elongate) or entire; venation areolate or free, if blades irregularly divided venation areolate ......................................................... 5

2 Proximal pinnae entire (rarely pinnate); venation areolate .............................................................................................................. 3

- Proximal pinnae forked; venation free ............................................................................................................................................. 4

3 Costal areoles with long axis angled towards pinna margins ...................................................................................... P. grandifolia

- Costal areoles with long axis parallel to costae ............................................................................................................ P. haenkeana

4 Stipes smooth; veins arising from costules ............................................................................................................... P. quadriaurita

- Stipes weakly aculeate; 1 or 2 basal veins arising from costae ........................................................................................ P. pungens

5 Blades usually 1-or 2-pinnate-pinnatifid (rarely 3-pinnate-pinnatifid at base), proximal pinna-pair furcate (basiscopic portion elongate) or pinnate and with venation areolate or free ................................................................................................................... 6

- Blades 2–5-pinnate-pinnatifid; proximal pinna-pair not furcate; venation areolate or free, or blades irregularly divided and venation areolate ........................................................................................................................................................................................... 14

6 Proximal pinna-pair furcate; blades pinnate-pinnatifid; venation areolate ...................................................................................... 7

- Proximal pinna-pair pinnate; blades usually 2-pinnate-pinnatifid (rarely more divided at base); venation areolate or free ........... 8

7 Apical pinna with base conspicuously long-decurrent onto the rachis; blades with sparse whitish hairs or glabrate ........................ .................................................................................................................................................................................. P. consanguinea

- Apical pinna with base very short-decurrent onto the rachis; blades copiously covered by whitish hairs ....................... P. lechleri

8 Venation free ..................................................................................................................................................................................... 9

- Venation areolate ............................................................................................................................................................................ 10

9 Costae and costules with spines abaxially ......................................................................................................................... P. inermis

- Costae and costules smooth abaxially ................................................................................................................................ P. deflexa

10 Costal areoles one between two adjacent costules; awns present on the adaxial side of costae .................................................... 11

- Costal areoles 2–4(–5) between two adjacent costules; awns present or absent on the adaxial side of costae .............................. 12

11 Blades ternate; proximal pinnae pedicellate, the pedicels not winged .................................................................................. P. livida

- Blades not ternate; proximal pinnae pedicellate, the pedicels winged .......................................................................... P. propinqua

12 Costal areoles 4 or 5 between two adjacent costules ....................................................................................................... P. lellingeri

- Costal areoles 2–3(–4) between two adjacent costules .................................................................................................................. 13

13 Awns present on the adaxial side of costae ..................................................................................................................... P. altissima

- Awns lacking along costae adaxially ............................................................................................................................ P. boliviensis

14 Blades irregularly divided; venation areolate ................................................................................................................................. 15

- Blades 2–5-pinnate-pinnatifid; venation areolate or free ............................................................................................................... 16

15 Rachises narrowly winged, the wings bearing thickened margins .............................................................................. P. denticulata

- Rachises not winged ........................................................................................................................................................... P. pearcei

16 Blades 4-or 5-pinnate-pinnatifid; venation areolate or free ........................................................................................................... 17

- Blades 3-or 4-pinnate-pinnatifid; venation free ............................................................................................................................. 19

17 Venation free; ultimate segments 1–1.5 mm wide ............................................................................................................... P. bakeri

- Venation areolate; ultimate segments larger than 5 mm wide ........................................................................................................ 18

18 Apices of segments serrate; ultimate segments falcate ................................................................................................ P. podophylla

- Apices of segments slightly crenate; ultimate segments not falcate ............................................................................... P. tripartita

19 Stipes with spines throughout .......................................................................................................................................... P. muricata

- Stipes lacking spines ....................................................................................................................................................................... 20

20 Costae abaxially with hairs ............................................................................................................................................... P. websteri

- Costae abaxially with hairs and scales ........................................................................................................................................... 21

21 Ultimate segments ca. 6 mm wide; costae and costules with scattered reddish brown hairs and scales ............. P. longipetiolulata

- Ultimate segments ca. 3 mm wide; costae and costules with dense indument of reddish brown hairs and a few scattered scales .... ............................................................................................................................................................................... P. muricatopedata