Phlegmariurus

Øllgaard, Benjamin, Kessler, Michael & Smith, Alan R., 2018, Prodromus of a fern flora for Bolivia. II. Lycopodiaceae, Phytotaxa 334 (3), pp. 255-294 : 268-269

Key to the Bolivian species of Phlegmariurus

1 Shoots and shoot apices erect, or ascending to erect, terrestrial or epiphytic; leaf margins entire, erose or denticulate................... 2

- Shoots pendulous, or initially erect with nodding to pendulous shoot apices, epiphytic or terrestrial; leaf margins entire ............ 17

2 Leaf margins denticulate (at least of some leaves, sometimes minutely and remotely denticulate) by pointed teeth, or ciliolate.... 3

- Leaf margins entirely smooth, or uneven, rugose to erose-rugose, without pointed teeth or cilia..................................................... 4

3 Leaves borne in alternating whorls of 4–5(–6), narrowly triangular-lanceolate, linear-lanceolate to nearly subulate, denticulate, (2.5–)3–5 × 0.5–1 mm at the base, spreading to strongly reflexed ...................................................................................... P. eversus

- Leaves borne in alternating whorls of (6–)7–8, linear-subulate to subulate, 4–10 × 0.5–1.2 mm, with very sparsely to densely and sharply denticulate to short-ciliolate margins throughout, ascending to spreading or sharply reflexed ............................ P. reflexus

4 Erect epiphytes, leaves spreading to ascending, filiform to linear, (6–) 10–17 mm long ................................................................... 5

- Erect terrestrial plants, leaves spreading, reflexed or appressed, linear-filiform to ovate ................................................................. 6

5 Leaves spreading, filiform, to 0.5 mm wide, usually not twisted at base, often with red color on the leaf bases .............. P. wilsonii

- Leaves spreading to ascending, linear, 0.7–1 mm wide, usually twisted at base, without red color............................. P. dichotomus

6 Leaves wide-spreading to reflexed or patent-ascending, the widest ones linear-filiform to lanceolate, without a basal swelling (air sac)...................................................................................................................................................................................................... 7

- Leaves, at least of sporangiate divisions appressed, the narrowest ones linear-lanceolate to broadly triangular-cordate and appressed, with or without a basal swelling, or leaves patent to reflexed and oblong, ovate or wider.................................................. 9

7 Broadest leaves of sporangiate divisions linear-filiform to subulate, spreading to reflexed, 0.5–1.3 mm wide, softly herbaceous.... ...................................................................................................................................................................................... P. hippurideus

- Leaves linear-lanceolate to ovate-lanceolate, 1.5–3 mm wide........................................................................................................... 8

8 Leaves reflexed to patent-ascending, recurved to slightly upward curved, thickly coriaceous, adaxially evenly convex, or with a slightly prominent vein, margins flat or involute, smooth ................................................................................................ P. weddellii

- Leaves papery to thinly subcoriaceous, folded slightly down along the vein, margins revolute, minutely rugose ..... P. brongniartii

9 Shoots homoblastic, without prostrate, rooting shoots..................................................................................................................... 15

- Shoots heteroblastic, with prostrate or subterranean, rooting shoots ............................................................................................... 10

10 Shoots prostrate, rooting on the soil surface, with erect aerial branches ......................................................................................... 11

- Shoots heteroblastic, with deeply subterranean, elongate, horizontal shoots bearing erect aerial branches.................................... 14

11 Aerial shoots somewhat club-shaped, compactly caespitose, narrowed and somewhat etiolated at the base and here with pale and irregularly appressed leaves; shoots strongly heteroblastic, the basal, prostrate shoots short and with much reduced leaves............ ........................................................................................................................................................................................... P. saururus

- Aerial shoots usually equally thick throughout, or tapering, loosely caespitose or distant, with conform basal leaves; shoots heteroblastic, the basal, prostrate shoots elongate...................................................................................................................................... 12

12 Aerial shoots usually short, unbranched, appearing narrower than creeping shoots; leaves of creeping shoots larger than those of aerial shoots ........................................................................................................................................................................ P. andinus

- Aerial shoots well developed, simple or branched, not appearing narrower than creeping shoots; leaves of creeping and aerial shoots of nearly equal size................................................................................................................................................................ 13

13 Leaves 5–9 × 1–2 mm, linear-lanceolate to lanceolate, with a prominent basal air cavity causing a perpendicular appearance of the junction to the stem in sporangiate leaves, dull, pruinous, usually reddish tinged, abaxially minutely rugose by protruding, blister-like epidermis cells (rarely smooth) ..................................................................................................................................... P. crassus

- Leaves (5–)7–10 × 1.5–2.5(–3) mm, lanceolate to ovate, dull to somewhat glossy, green, abaxially smooth or slightly rugose, leaf margins usually minutely rugose by individually protruding cells, upwardly curved at apex.......................................... P. stephanii

14 Leaves of aerial branches 4–6(–7) × 1.2–1.8(–2) mm, linear-lanceolate to lanceolate, the proximal ones usually arcuate-appressed; plants tinged with red or entirely red.............................................................................................................................. P. hypogaeus

- Leaves 8–12 × (1.5–) 2–2.3 mm, loosely ascending in lower, non-sporangiate divisions, upwardly gradually shorter, 6–9 × 1.5–2 mm; plants green or slightly reddish tinged ................................................................................................................... P. talpiphilus

15 Leaf whorls 3–4 mm apart, usually not concealing the stem, leaves spreading to ascending, upwardly curved, broadly lanceolate to ovate-lanceolate, rounded at the base, 6–9 × 2.3–2.8 mm, adaxially concave, abaxially rounded, especially at apices................. ............................................................................................................................................................................................. P. pflanzii

- Leaf whorls 1–2.5 mm apart, usually concealing the stems: leaves spreading to appressed, straight to slightly upwardly curved, lanceolate to broadly lanceolate, not or slightly rounded at the base, (5–)7–11 × 1.5–2.5(–3)mm, adaxially concave, abaxially evenly rounded ................................................................................................................................................................................. 16

16 Leaves straight, patent-ascending thoughout, lanceolate to triangular-lanceolate, acute to short-acuminate, 8–11 × 2(–2.5) mm, adaxially concave, abaxially evenly rounded throughout, leaf margins smooth................................................................... P. acutus

– Leaves crowded, loosely to closely imbricate, upwardly curved, lanceolate to ovate, acute to slightly acuminate, (5–)7–10 × 1.5–2.5(–3) mm, leaf margins often minutely rugose by individually protruding cells..................................................... P. stephani

17 Shoots with more or less sharply dimorphic leaves; basal divisions with long expanded leaves; apical divisions constricted, with appressed, reduced, decussate or subdecussate leaves, or entire plants covered by appressed, short, broad, decussate leaves ...... 18

– Leaves uniform throughout, or gradually smaller toward the shoot apices; not abruptly constricted; leaves of terminal divisions not predominantly decussate or subdecussate ........................................................................................................................................ 20

18 Contricted divisions sharply quadrangular, expanded leaves of basal divisions very uniform in size, shape, and position throughout, closely situated, with almost continuously overlapping leaf margins (pressed specimens), borne in alternating whorls of 3 at the base, broadly lanceolate to ovate, acute; stems not red............................................................................................. P. ericifolius

– Constricted divisions bluntly quadrangular to subterete, with leaves rounded to bluntly carinate abaxially, expanded leaves not continuously overlapping, decussate, subdecussate or in alternating whorls of 3 at the base, linear-subulate to lanceolate, to 2 mm wide, stems with or without red color .............................................................................................................................................. 19

19 Expanded leaves linear, or linear-subulate to linear-lanceolate, 0.5–1 mm wide ............................................................ P. subulatus

– Expanded leaves linear-lanceolate to lanceolate, 1.3–2 mm wide .............................................................................. P. phylicifolius

20 Plants slender to robust; longest leaves of basal divisions more than 8 mm long; leaves filiform or linear to lanceolate; stems 0.5–5 mm thick........................................................................................................................................................................................... 21

– Plants very delicate, the longest leaves less than 6(–8) mm long, acicular, less than 0.5 mm wide; stems less than 1 mm thick at base................................................................................................................................................................................................... 27

21 Leaves of basal divisions alternate or paired, or occasionally in whorls of three ............................................................................ 22

– Leaves of basal divisions predominantly or entirely whorled, without petiole-like laminar bases, the longest ones 8–23 mm long; stem bases 0.5–5 mm or more thick ................................................................................................................................................. 23

22 Leaves of basal divisions more than 13 × 1–4 mm, each with a narrowed, twisted, often petiole-like and approximately perpendicular laminar base; leaves of terminal divisions alternate to whorled; stem bases usually 1 mm or less thick excluding leaves ........... ........................................................................................................................................................................................... P. linifolius

– Leaves of basal divisions 5–10(–12) × 0.4–0.7(–1) mm, distant throughout, twisted to vertical, not petiole-like, stems 0.5 mm or less thick, leaves distant throughout, not whorled, straight to falcately curved, linear-lanceolate .................................. P. capillaris

23 Leaves filiform to linear, to 1 mm wide ........................................................................................................................................... 24

– Leaves linear-lanceolate to lanceolate, the widest ones more than 1.5 mm wide ............................................................................ 26

24 Leaves not twisted at base, filiform or linear, 0.3–0.7 mm wide just above the leaf base ............................................................... 25

– Leaves twisted at base, obliquely falcate-ascending, (8–)10–17 × 0.7–1 mm, stems 2–3 mm thick at bases .............. P. dichotomus

25 Leaves perpendicularly spreading to slightly upwardly curved, or ascending, (6–) 10–17 mm long, slightly canaliculate adaxially, with green or bright red leaf bases; stems usually 1.5–2 mm thick .................................................................................... P. wilsonii

– Leaves ascending to loosely appressed, linear to linear-subulate, 7–13 mm long, flat or convex adaxially, usually somewhat revolute, each with sharply prominent vein below at least in the basal half; stems 0.5–1 mm thick at base....................... P. mollicomus

26 Leaves of fully sporangiate divisions 6(–8)-ranked, twisted or straight at base, 2–2.5 mm wide, partly concealing the stem and sporangia........................................................................................................................................................................... P. taxifolius

– Leaves of fully sporangiate divisions 10(–12)-ranked, not twisted at base, often strongly involute at apex, 1.5–2 mm wide, almost completely concealing the stem and sporangia ....................................................................................................................... P. sotae

27 Leaves of apical divisions not, or slightly different from those of basal divisions; leaves uniformly crowded throughout, patent-ascending; leaf bases also of sporangiate leaves only slightly broadened above the base................................................ P. acerosus

– Leaves of apical divisions distinctly shorter, with a broader base, and usually less crowded than those of basal divisions, patent to appressed .......................................................................................................................................................................................... 28

28 Non-sporangiate leaves of narrow terminal divisions closely appressed to the stem, with cuneate to rounded bases; terminal divisions usually with short, densely and omnilaterally sporangiate zones ........................................................................... P. filiformis

– Non-sporangiate leaves of terminal divisions with a patent, rounded to auriculate or subhastate leaf bases; terminal divisions usually with evenly and often sparsely and unilaterally sporangiate zones................................................................................. P. tenuis