Phlegmariurus, Holub

Øllgaard, Benjamin & Testo, Weston, 2021, The Lycopodiaceae of Panamá, Phytotaxa 526 (1), pp. 1-66 : 5-7

Key­­­to­­­the­­­species­­­of­­­ Phlegmariurus

1a. Erect, or ascending to erect, with erect shoot apices, terrestrial or epiphytic.

2a. Leaf margins denticulate (at least in some leaves, sometimes minutely and sparsely denticulate) by pointed teeth, ciliolate, or fimbriate.

3a. Leaves closely imbricate throughout, borne in irregular alternating whorls of 5–6, narrowly oblong to lanceolate throughout, abaxially convex and rounded, with denticulate-serrate margins.......................................................................... 6. P. chiricanus

3b. Leaves patent to reflexed.

4a. Terrestrial (rarely on the base of trees), leaves linear-subulate to lanceolate, denticulate throughout or at the base only, sometimes with very sparse teeth, not red-dotted.

5a. Relatively small and slender plants, with linear-subulate to lanceolate leaves, 4–8 × 0.5–1.2 mm, with densely to sparsely toothed margins; sporangia 1–1.5 mm wide.

6a. Shoots narrow, usually 3–8 mm in diam. incl. leaves, with leaves borne in alternating whorls of 5–6, usually 4–6 mm long, linear-lanceolate to lanceolate, usually strongly recurved. ............................................................................. 12. P. eversus

6b. Shoots usually 7–15 mm in diam. incl. leaves, with leaves borne in alternating whorls of 7–8, usually 4–8 mm long, linear-subulate, straight to strongly recurved. .......................................................................................................... 24. P. reflexus

5b. Relatively large and robust plants, with lanceolate leaves, 5–8 × 1.2–2 mm, with sparsely toothed to nearly entire margins; sporangia 1.5–2 mm wide............................................................................................................................. 17. P. hoffmannii 4b. Epiphytic, leaves oblong-elliptic to oblanceolate from a narrow, long-cuneate base, only apically denticulate, sometimes with red-dotted leaf bases. .......................................................................................................................................... 14. P. foliaceus

2b. Leaf margins entire, or minutely rugose by protruding marginal cells, or unevenly erose, not denticulate (see also discussion under P. reflexus ).

7a. Leaves linear or filiform to subulate, reflexed or spreading to ascending, not appressed, or linear-lanceolate with a narrowed petiole-like lamina base.

8a. Leaves linear or filiform to subulate, long-acute to gradually tapering into a long narrow apex, 4–35 × 0.3–1.3 mm.

9a. Leaves long, linear or filiform, the longest leaves usually much more than 10 mm long

10a. Leaves linear to linear-subulate, usually 8–19 × 0.7–1.3 mm, slightly convex to canaliculate above, without prominent and red decurrent leaf bases. ........................................................................................................................... 16. P. hippurideus

10b. Leaves filiform, usually 10–17 × 0.3–0.5 mm, often red tinged at base. ........................................................... 31. P. wilsonii

9b. Leaves short, subulate, the longest leaves usually less than 8 mm long............................................................. 5. P. chamaeleon

8b. Leaves linear-lanceolate with a narrowed petiole-like lamina base, with short-acute to obtuse apex, 7–11 × 1–1.5 mm ................ ........................................................................................................................................................................... 3. P. bradeorum

7b. Leaves linear-lanceolate (without a narrowed petiole-like lamina base) ascending to closely imbricate, 4–11 × 1–3 mm.

11a. Leaves (4–) 5–8 × 1–1.5 (–1.8) mm, usually closely imbricate, usually rugose abaxially due to protruding, blister-like epidermal cells, usually pruinous. ............................................................................................................................................ 7. P. crassus

11b. Leaves (6–) 8–11 × (1.5–) 2–3 mm, ascending to loosely imbricate, abaxially smooth and often shining, or sometimes with few protruding, blister-like epidermal cells, not pruinous................................................................................. 26. P. talamancanus

1b. Pendulous, or initially erect with nodding to pendulous shoot apices, usually epiphytic; leaf margins not denticulate or erose (see also P. wilsonii ).

12a. Shoots with more or less sharply dimorphic leaves; basal divisions with long expanded leaves; apical divisions constricted, with appressed, reduced, usually decussate, sporangiate leaves. 14

13a. Expanded leaves lanceolate or oblanceolate to oblong or obovate, 1.5–5 mm wide.

14a. Expanded leaves of basal divisions usually uniform in size, shape, and position throughout, closely situated, with usually continuously overlapping leaf margins (pressed specimens).

15a. Expanded leaves elliptic to ovate, obtuse or mucronulate, 6–9 x 3–4 mm; constricted divisions usually less than 10 cm long, usually sporangiate throughout; sporophylls 1.2–1.5 (–2.7) × 1 (–1.3) mm, equalling or slightly longer than the sporangia, short-cuspidate............................................................................................................................................. 10. P. dichaeoides

15b. Expanded leaves ovate to elliptic-oblong, 6–11 × 2.8–4 mm, slightly apiculate constricted divisions commonly more than 20 cm long, with extensive non-sporangiate zones; sporophylls 3–4.5 × 1.5 mm, usually more than 1.5 x longer than the sporangia.. ................................................................................................................................................................................ 2. P. aqualupianus

14b. Expanded leaves 3–6 × 1–2 mm, oblanceolate to obovate, cuneate at base; stem pale to bright red.................... 8. P. cuneifolius

13b. Expanded leaves narrowly lanceolate to linear-subulate, to 1 mm wide .................................................................. 25. P. subulatus

12b. Leaves uniform throughout, or gradually smaller toward the shoot apices; leaves of terminal divisions not predominantly decussate, sporangiate or not.

16a. Plants slender to robust; longest leaves of basal divisions more than 8 mm long; leaves linear-subulate to lanceolate or elliptic, (0.7–) 1–5 mm wide, stems 0.3–5 mm thick.

17a. Leaves of basal divisions alternate or paired, or in occasional whorls of 3, with a narrowed, twisted, often petiole-like and approximately perpendicular lamina base; leaves of terminal divisions alternate to whorled; stem base usually 1 mm or less thick excl. leaves, with or without red colour.

18a. Longest leaves more than 13 mm long, 1–4 mm wide, stems not red. ................................................................. 20. P. linifolius

18b. Longest leaves 7–10 (–12) mm long, to 1 mm wide, stems with or without red colour ...................................... 4. P. capillaris

17b. Leaves predominantly or entirely whorled or paired, or with some solitary leaves, with or without petiole-like lamina bases, stems 0.5–5 mm thick, not coloured.

19a. Shoots cord-like; leaves closely appressed throughout, except in deeply shaded individuals, subulate, usually apically conduplicate, borne in alternating whorls of 7 or 8....................................................................................... 15. P. funiformis

19b. Shoots not cord-like; leaves ascending to patent at least in basal divisions, linear to lanceolate or oblanceolate, borne in whorls of (2–) 3 to 6, or if leaves appressed throughout nearly flat abaxially.

20a. Leaves borne in whorls of 5–6, linear to linear-subulate (8–) 10–15 (–17) × 0.7–1 mm .............................. 11. P. dichotomus

20b. Leaves borne in whorls of (2–) 3–4, linear-lanceolate to lanceolate, or linear-oblanceolate.

21a. Lamina usually vertical with twisted and somewhat petiole-like base, leaves linear to linear-lanceolate, 7–10 × 1–1.5 mm, acute........................................................................................................................................................ 19. P. lancifolius

21b. Lamina transversal or vertical, twisted or not, not petiole-like at base, leaves linear to broadly elliptic or lanceolate.

22a. Leaves of basal division linear to lanceolate

23a. Leaves of basal divisions linear-lanceolate to linear-oblanceolate or lanceolate, twisted or straight, 9–23 mm long, 1–3.5 mm wide; leaves of distal divisions conform to much shorter and apically involute.

24a. Stems excl. leaves 1.5–2.5 mm thick; leaves of basal divisions linear-lanceolate to lanceolate, 14–23 × 2–3 mm; sporangia 1–3 mm wide................................................................................................................... 27. P. taxifolius

24b. Stems excl. leaves 1–1.5 mm thick; leaves of basal divisions linear-lanceolate to linear-oblanceolate, 9–15 × 1–2 mm; sporangia 1–1.2 mm wide ...................................................................................................... 29. P. tubulosus

23b. Leaves of basal divisions linear to linear-lanceolate, twisted, 10–14 mm long, 1–1.5 mm wide; leaves of distal divisions nearly conform and equally spaced, not involute .......................................................................... 18. P. homocarpus

22b. Leaves of basal divisions 12–15 × 4–5 mm, elliptic to broadly lanceolate, obtuse to broadly acute; leaves of fully sporangiate divisions 6–8 × 2.5–3 mm, broadly lanceolate, flat or nearly so............................ 21. P. mesoamericanus

16b. Plants delicate, stems excl. leaves (0.6–) 1–1.5 mm thick at base, the longest leaves 3–13 mm long, acicular, linear, linear-subulate or filiform, less than 0.7 mm wide. 25a. Leaves of apical divisions (incl. sporophylls) nearly conform to the basal ones, not, or slightly shorter; leaves uniformly crowded throughout, spreading to ascending, linear to linear-subulate or filiform, 4–13 mm long.

26a. Leaves without widened subauriculate, revolute lamina bases, 7–15 mm long, wide-spreading to loosely appressed.

27a. Leaves straight, not twisted at base, with sharply prominent vein abaxially and slightly revolute margins............................. .................................................................................................................................................................. 22. P. mollicomus

27b. Leaves usually twisted at base, adaxially flat to canaliculate, often with an abaxially prominent vein at base ....................... ................................................................................................................................................................... 23. P. polycarpos

26b. Leaves with widened, subauriculate, usually strongly revolute lamina bases, 4–6 (–9) mm long, uniformly spreading to ascending.................................................................................................................................................... 30. P. watsonianus

25b. Plants very delicate, the longest leaves less than 6 (–8) mm long, acicular, less than 0.5 mm wide; stems excl. leaves less than 1 mm thick at base.

28a. Leaves of apical divisions not, or slightly different from those of basal divisions; leaves rather uniformly crowded throughout, patent-ascending; leaf bases also of sporangiate leaves only slightly widened above the base ........................ 1. P. acerosus

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

29a. Non-sporangiate leaves of narrow terminal divisions closely appressed to the stem, with cuneate to rounded base.

30a. Leaves of basal divisions straight to slightly upward curved, patent to appressed; terminal divisions usually with short, densely and omnilaterally sporangiate zones............................................................................................ 13. P. filiformis

30b. Leaves of basal divisions usually strongly upward and inward curved from a patent base, or sigmoid; terminal divisions usually with few scattered sporangia, usually discontinuously and unilaterally sporangiate for every third to fifteenth (or more) leaf ............................................................................................................................................ 9. P. curvifolius

29b. Non-sporangiate leaves of terminal divisions with a patent, rounded to auriculate or subhastate leaf base ........ 28. P. tenuis