Key to the species of Eriocaulaceae from the Chapada dos Veadeiros National Park

1. Flowers diplostemonous; petals with glands ................................... Eriocaulon L. (not treated here)

– Flowers isostemonous; petals without glands ..................................... 2 (Paepalanthoideae Ruhland)

2. Lateral branches subtending the scapes (paraclades) entirely covered by bracts ............................... ......................................................................................................... 3 (Actinocephalus (Körn.) Sano)

– Lateral branches subtending the scapes usually absent, when present, not covered by bracts ......... 4

3. Rhizome present; leaves linear, 0.5−2.0 × 0.05−0.1 cm.; paraclades ca 8−35 per rosette, covered by linear bracts, 0.5−1.5 × 0.05−0.1 cm ............ Actinocephalus brevifolius Trovó & Echtern. sp. nov.

– Rhizome absent; leaves lanceolate, 4.0−8.5 × 0.5−0.9 cm.; paraclades ca 4−8 per rosette, covered by lanceolate bracts, 2.0−5.5 × 0.3−0.5 cm ........ Actinocephalus phaeocephalus (Ruhland) F.N.Costa

4. Petals of the pistillate flower completely free ................................................ 5 (Paepalanthus Mart.)

– Petals of the pistillate flowers fused at the middle ......................................................................... 28

5. Flowers trimerous ............................................................................................................................. 6

– Flowers dimerous ............................................................................................................................ 10

6. Stem conspicuously elongated,> 15 cm long, ramified ................ Paepalanthus scandens Ruhland

– Stem shortly elongated, <15 cm long, not ramified ......................................................................... 7

7. Involucral bracts of the external series linear, green ............. Paepalanthus bifidus (Schrad.) Kunth

– Involucral bracts of the external series elliptical, ovate or lanceolate, hyaline or castaneous .......... 8

8. Involucral bracts castaneous, ovate, densely ciliate .................. Paepalanthus polytrichoides Kunth

– Involucral bracts hyaline, elliptical or lanceolate, mostly glabrous at the margin ........................... 9

9. Scapes sparsely pilose to usually glabrescent; capitula campanulate, glabrous; involucral bracts elliptical; stigmatic branches bifid at the apex ........................... Paepalanthus campanulatus Trovó

– Scapes pilose with persistent trichomes; capitula hemispherical, pilose; involucral bracts lanceolate; stigmatic branches simple ....................................................................... Paepalanthus subtilis Miq.

10. Stem restricted to the rosette, <10 cm long ....................................................................................11

– Stem conspicuously elongated,> 10 cm long ................................................................................ 18

11. Capitula spherical, rarely hemispherical; receptacle hemispherical ............................................... 12

– Capitula discoid, rarely hemispherical; receptacle flat ................................................................... 14

12. Amphibious; leaves patent; scapes with long, loose trichomes ....... Paepalanthus amphibius Trovó

– Terrestrial; leaves recurved; scapes glabrous or with hirsute or adpressed trichomes ................... 13

13. Spathes <1 cm long, dark brown; scapes 35–160, <10 cm long, glabrous or rarely covered by adpressed trichomes; capitula ca 2 mm diam. ................................. Paepalanthus echinoides Trovó

– Spathes> 1.2 cm long, green; scapes 1–5,> 10 cm long, with hirsute trichomes; capitula ca 0.5 mm diam. ................................................................................. Paepalanthus sphaerocephalus Ruhland

14. Leaf sheath castaneous; involucral bracts of the external series golden to pale straw-colored, twice the length of the floral disc ................................................................... Paepalanthus cassiae Trovó

– Leaf sheath pale straw-colored or yellowish to golden; involucral bracts of the external series golden, varying from grayish to blackish, slightly or 1× surpassing the floral disc .................................... 15

15. Leaf sheath yellowish to golden; involucral bracts of the external series linear, greyish to dark castaneous with a central whitish stripe, 1× surpassing the floral disc ............................................... .............................................................................. Paepalanthus longibracteatus (Moldenke) Trovó

– Leaf sheath pale straw-colored; involucral bracts of the external series lanceolate to oblong, light castaneous to blackish without a central whitish stripe, slightly surpassing the floral disc ........... 16

16. Gracile herbs; leaves <1 mm wide; capitula <1 cm diam., discoid to hemispherical ........................ ............................................................................................................ Paepalanthus modestus Trovó

– Robust herbs; leaves> 1.5 cm wide; capitula> 1.5 cm diam., discoid .......................................... 17

17. Spathes and scapes densely pilose, sericeous, involucral bracts dark castaneous to blackish, capitula> 2.5 cm wide ....................................................................... Paepalanthus niger (Moldenke) Trovó

– Spathes and scapes usually glabrous to sparsely pilose, involucral bracts light castaneous, capitula <2.5 cm wide ............................................................ Paepalanthus politus Trovó stat. et nom. nov.

18. Gracile herbs; basal rosette absent, stem ramified .......................................................................... 19

– Robust herbs; basal rosette present, stem not ramified ................................................................... 21

19. Involucral bracts golden to paleaceous when old ................. Paepalanthus flaccidus (Bong.) Kunth

– Involucral bracts castaneous ........................................................................................................... 20

20. Leaves usually glabrous, apex acute; spathes> 3.5 cm long, mostly glabrous; scapes glabrous; capitula ca 3 mm wide; floral bracts linear ......................................................................................... ..................................................................... Paepalanthus atratus (Moldenke) L.E.F.Silva & Trovó

– Leaves densely pilose and ciliate, apex mucronate to acuminate; spathes <3.0 cm long, hirsute; scapes hirsute; capitula ca 6 mm wide, floral bracts oblong ............................................................... ........................................................................................ Paepalanthus trichophyllus (Bong.) Körn.

21. Leaves oblong, apex cuspidate; bracts of the inflorescence axis strongly recurved, cordate ............. ......................................................................................................... Paepalanthus cordatus Ruhland

– Leaves lanceolate or linear, apex acute to mucronate; bracts of the inflorescence axis patent to erect, lanceolate or linear .......................................................................................................................... 22

22. Bracts of the inflorescence axis strongly appressed; capitula sulfurous ............................................. ................................................................................................................. Paepalanthus macer Trovó

– Bracts of the inflorescence axis usually patent or ascending, but then lax; capitula whitish ......... 23

23. Bracts of the inflorescence axis ascending, membranaceous .............. Paepalanthus stellatus Trovó

– Bracts of the inflorescence axis patent, chartaceous ....................................................................... 24

24. Leaves of the uppermost series contort, apex mucronate; scapes mostly with the same size of the inflorescence axis ....................................................................... Paepalanthus urbanianus Ruhland

– Leaves of the uppermost series straight, apex acute; scapes much shorter than the inflorescence axis .................................................................................................................................................. 25

25. Plants <120 cm tall; leaves deciduous, <8.0 cm long; reproductive axis <80.0 cm long; scapes <100 ............................................................................................................................................... 26

– Plants> 130 cm tall; leaves persistent,> 9.0 cm long; reproductive axis> 100.0 cm long; scapes> 100 ............................................................................................................................................... 27

26. Plant up to 60 cm tall; leaves linear, 1.0−3.0 × 0.1−0.2 cm.; reproductive axis ca 45.0 cm tall and 0.3 cm diam.; axis bracts linear to narrowly lanceolate, 0.5−1.5 × 0.1−0.3 cm.; up to 25 scapes per plant; capitula ca 0.9 cm diam. .............................. Paepalanthus irwinii Trovó & Echtern. sp. nov.

– Plant up to 120 cm tall; leaves lanceolate, 3.5−8.0 × 0.3−0.7 cm.; reproductive axis ca 100.0 cm tall and 0.6 cm diam.; axis bracts lanceolate, 1.0−5.5 × 0.8−1.2 cm.; up to 80 scapes per plant; capitula ca 1.5 cm diam. .................................................................... Paepalanthus acanthophyllus Ruhland

27. Bracts of the inflorescence axis varying in shape along the axis, becoming smaller from the base to the apex ....................................................................................... Paepalanthus chiquitensis Herzog

– Bracts of the inflorescence axis with similar shape along the axis, with the same size from the base to the apex ....................................................................... Paepalanthus koernickei (Ruhland) Trovó

28. Flowers dimerous; sepals of the pistillate flowers shorter than petals, petals with erect, spatulate lobes. .................................................................................................... Comanthera dimera Echtern.

– Flower trimerous; sepals of the pistillate flowers longer than petals, petals with often involute, triangular lobes .......................................................................................29 (Syngonanthus Ruhland)

29. Simple inflorescences, scapes arising from the stem, axillary to the leaves ................................... 30

– Compound inflorescences (synflorescences), scapes arising from the synflorescence axis, axillary to the axis bracts ................................................................................................................................. 37

30. Stem subterranean or restricted to the basal rosette of leaves ........................................................ 31

– Stem aerial, basal rosette absent, leaves spirulate along the stem .................................................. 35

31. Involucral bracts brown .................................................................................................................. 32

– Involucral bracts cream-colored to golden ..................................................................................... 33

32. Roots orangish, leaves semi-terete ............................................. Syngonanthus cabralensis Silveira

– Roots cream-colored, leaves flat to canaliculate.................................................................................. ........................................................................ Syngonanthus hensoldiae M.T.C.Watanabe & Sano

33. Pistillate flowers twice the length of staminate flowers; petals of pistillate flower hairy ................... .................................................................................... Syngonanthus heteropeplus (Körn.) Ruhland

– Pistillate flowers similar in length to the staminate flowers; petals of pistillate flower glabrous ....... 34

34. Roots spongy, orangish; gynoecium with nectariferous appendices; involucral bracts appressed, progressively longer toward the internal series; scape golden ........................................................... ............................................................................................... Syngonanthus nitens (Bong.) Ruhland

– Roots fibrous, cream-colored; gynoecium without nectariferous appendices; involucral bracts lax, medium and internal series similar in height; scape stramineous ......... Syngonanthus davidsei Huft

35. Flowers bisexual; spathes and scapes with capitate hairs; petals membranaceous ............................ ........................................................................................ Syngonanthus androgynous M.T.C.Watan.

– Flowers unisexual; spathes and scapes without capitate hairs; petals spongy ................................ 36

36. Scapes shorter than or equal to the leaf length; involucral bracts cream-colored, with stramineous to greenish longitudinal band; floral bracts present; petals of pistillate flowers glabrous ...................... ........................................................ Syngonanthus cuyabensis (Bong.) Giul., Hensold & L.R.Parra

– Scapes longer than the leaf length; involucral bracts completely cream-colored; floral bracts absent; petals of pistillate flowers hairy ...................................... Syngonanthus caulescens (Poir.) Ruhland

37. Stem aerial or aquatic; synflorescence axis shorter than leaves, hidden ............................................ ................................................................................... Syngonanthus widgrenianus (Körn.) Ruhland

– Stem subterranean; synflorescence axis longer than leaves, conspicuous ...................................... 38

38. Synflorescence with whorls of bracts along the axis and at the apex; involucral bracts cream-colored, stramineous to golden; leaves with capitate hairs ....... Syngonanthus humboldtii (Kunth) Ruhland

– Synflorescence with one whorl of bracts at apex; involucral bracts brown; leaves without capitate hairs ................................................................................................................................................. 39

39. Involucral bracts abaxially glabrous, discolorous, the external brown, the internal cream-colored; floral bracts present ....................................................................... Syngonanthus decorus Moldenke

– Involucral bracts abaxially hairy, similar or gradual in color, all series brown; floral bracts absent .... 40

40. Pistillate flowers glabrous; involucral bracts narrow-lanceolate ........................................................ ............................................................................... Syngonanthus vittatus M.T.C.Watan. & Echtern.

– Pistillate flowers hairy; involucral bracts triangular, ovate, oblanceolate to obovate .................... 41

41. Leaves cespitose, erect to flexuous; involucral bracts with a lighter central band ............................. ................................................................................ Syngonanthus densifolius var. majus Moldenke

– Leaves in distinct basal rosettes, ascending, recurved or incurved; involucral bracts mostly homogeneously brown or margins lighter than the center .............................................................. 42

42. Leaves distally incurved, 0.7−1.2 mm wide ....................................................................................... ...................................................................... Syngonanthus incurvifolius M.T.C.Watan. & Echtern.

– Leaves ascending to recurved, 2−5 mm wide ..................................................................................... .................................................................. Syngonanthus densifolius var. brachyphyllus Moldenke