Sticherus

Kessler, Michael & Smith, Alan R., 2018, Prodromus of a fern flora for Bolivia. XI. Gleicheniaceae, Phytotaxa 344 (1), pp. 53-63 : 57-58

Key to the Bolivian species of Sticherus

1 Segments rounded, oval or triangular, <1 cm long ........................................................................................................................... 2

– Segments linear or oval,> 1 cm long ................................................................................................................................................ 7

2 Abaxial segment surfaces densely scaly with arachnoid scales; midvein scales triangular to rounded ........................................... 3

– Abaxial segment surfaces glabrous or sparsely scaly; midvein scales linear to filamentous ........................................................... 4

3 Last branches with semicircular to winglike internal segments broader than long; bud scales lanceolate, bicolorous, ciliate and/or setulose ....................................................................................................................................................................... S. aurantiacus

– Last branches bearing internal segments longer than broad; bud scales ovate, uniformly translucent, ciliate ... S. brevitomentosus

4 Pseudostipules present; bud scales to 1 mm long ............................................................................................................................. 5

– Pseudostipules absent or rudimentary; bud scales over 1 mm long ................................................................................................. 6

5 Rhizomes bearing squamophores; bud scales concolorous, orange .............................................................................. S. pruinosus

– Rhizomes lacking squamophores; bud scales bicolorous, pale orange with dark brown bases ..................................... S. revolutus

6 Rhizomes lacking squamophores; bud scales bicolorous, pale orange with dark brown bases ................................... S. boliviensis

– Rhizomes bearing squamophores; bud scales concolorous, dull orange ......................................................................... S. nervatus

7 Abaxial segment surfaces densely scaly throughout ................................................................................................... S. tomentosus

– Abaxial segment surfaces glabrous or sparsely scaly or scaly only on midveins ............................................................................ 8

8 Segments remote, at least on the proximal branches; scales abaxially on branches bicolorous with dark bases, apices, or centers .. ........................................................................................................................................................................................................... 9

– Segments approximate on all branches; segments linear to oblong; scales abaxially on branches translucent or centrally darkened ......................................................................................................................................................................................................... 12

9 Pseudostipules lacking; bud scales entirely dark .................................................................................................... S. melanoblastus

– Pseudostipules present; bud scales bicolorous ............................................................................................................................... 10

10 All branches remotely pinnatisect, midvein scales stellate; sori not nested within arachnoid scales .............................. S. remotus

– Only 1 st branches remotely pinnatisect; midvein scales linear and/or triangular; sori nested within arachnoid scales ................. 11

11 1 st branches longer than 2 nd branches; branches lacking wings between segments; abaxial segment surfaces densely scaly ........ S. jacha

– 1 st branches shorter than 2 nd branches; branches with wings between the segments; abaxial segment surfaces sparsely scaly .......... ............................................................................................................................................................................... S. nigropaleaceus

12 Pseudostipules lacking; last branches lacking proximal internal segments, branch outlines lanceolate, equally or unequally truncate basally ......................................................................................................................................................................... S. bifidus

– Pseudostipules present, trifid to simple; last branches with proximal internal segments gradually reduced, branch outlines lanceolate or linear .................................................................................................................................................................................... 13

13 Bud scales opaquely whitish to speckled, with dark apices, the margins with delicate cilia 1/5–1/7 the scale length. S. decurrens

– Bud scales concolorous and translucent, or bicolorous with dark bases, margins with delicate or short, thick cilia .................... 14

14 Midvein scales filamentous; branches>3-forked ........................................................................................................................... 15

– Midvein scales lanceolate to linear; branches to 3-forked, rarely more divided ............................................................................ 16

15 Proximal branches thick, very short; segments 0.5–2 cm long, ca. 3 segments per cm ............................................ S. lanuginosus

– Proximal branches usually slender, relatively long; segments more than 3 cm long, ca. 2 segments per cm .................... S. velatus

16 Segments> 3 cm long; bud scales thick-textured ........................................................................................................................... 17

– Segments <3 cm long; bud scales thin-textured ............................................................................................................................. 18

17 All branches scaly abaxially; bud scales basally dark brown ............................................................................................ S. lanosus

– Only proximal branches densely scaly abaxially, distal axes glabrous to sparsely scaly; bud scales whitish .............. S. pallescens

18 Bud scales translucent with dark margins .................................................................................................................. S. rubiginosus

– Bud scales entirely translucent or with dark bases or centers ........................................................................................................ 19

19 Midveins sparsely scaly to glabrous abaxially; bud scales translucent, orange ................................................................ S. lechleri

– Midveins densely scaly abaxially; bud scales bicolorous, translucent, whitish with dark brown bases ..................... S. peruvianus