Xyris fallax

<<<<Scapes>Spikes>Floral bracts>Shape>Length

5-7 mm1

1. 003-004-005-001-001

<<<Scapes>Spikes>Empty bracts>Bract number

several2

2. 003-004-004-001

<<<Scapes>Spikes>Floral bracts>Shape

broadly ovate to obovate, , subentire, narrowly rounded, convex, with distinct dorsal area bisected by a distinct, evidently branched midvein3

3. 003-004-005-001

<<Capsules>Seeds>Colour

amber4

4. 005-003-003

<<Capsules>Seeds>Length

1-1.5 mm5

5. 005-003-002

<<Capsules>Seeds>Shape

cylindric or fusiform6

6. 005-003-001

<<Lateral sepals>Anthers>Length

ca. 1.5 mm7

7. 004-006-001

<<Lateral sepals>Keel>Hairs

lacero-ciliate from middle to apex8

8. 004-003-001

<<Lateral sepals>Petals>Length

4-5 mm9

9. 004-004-002

<<Lateral sepals>Petals>Shape

obovate10

10. 004-004-001

<<Lateral sepals>Staminodes>Shape

bearded11

11. 004-005-001

<<Leaves>Blade>Shape

flattened12

12. 002-005-001

<<Leaves>Blade>Width

1-5(-7) mm wide13

13. 002-005-002

<<Leaves>Margins>Colour

lustrous14

14. 002-006-001

<<Leaves>Margins>Texture

smooth, less often papillose or scabridulous15

15. 002-006-002

<<Leaves>Sheaths>Hairs

ciliate16

16. 002-004-001

<<Leaves>Sheaths>Ligula

apically with short-triangular ligule17

17. 002-004-003

<<Leaves>Sheaths>Shape

narrowing to blade18

18. 002-004-002

<<Scapes>Spikes>Empty bracts

empty bracts , grading larger into flowering bracts19

19. 003-004-004

<<Scapes>Spikes>Floral bracts

these20

20. 003-004-005

<<Scapes>Spikes>Flower number

many-flowered21

21. 003-004-003

<<Scapes>Spikes>Length

1-2 cm22

22. 003-004-002

<<Scapes>Spikes>Shape

ovoid to lance-cylindric or ellipsoid23

23. 003-004-001

<Capsules>Length

3-5 mm24

24. 005-001

<Capsules>Placentation

placentation parietal25

25. 005-002

<Capsules>Seeds

seeds , , .26

26. 005-003

<Habit>Height

20-100 cm high27

27. 001-003

<Habit>Shape

Slender to coarse28

28. 001-001

<Habit>Stems

stems short, sometimes rhizomatous.29

29. 001-004

<Habit>Texture

smooth30

30. 001-002

<Lateral sepals>Anthers

anthers .31

31. 004-006

<Lateral sepals>Keel

keel32

32. 004-003

<Lateral sepals>Length

4.5-5 mm33

33. 004-002

<Lateral sepals>Petals

petals , ;34

34. 004-004

<Lateral sepals>Shape

linear-oblanceolate35

35. 004-001

<Lateral sepals>Staminodes

staminodes ;36

36. 004-005

<Leaves>Blade

blade , ,37

37. 002-005

<Leaves>Colour

often with maroon pigment38

38. 002-003

<Leaves>Growth form

erect or in a fan39

39. 002-001

<Leaves>Length

(5-)10-30(-40) cm40

40. 002-002

<Leaves>Margins

margins , thickened, .41

41. 002-006

<Leaves>Sheaths

sheath or entire, ,42

42. 002-004

<Scapes>Ribs

with several strong ribs43

43. 003-003

<Scapes>Shape

distally terete44

44. 003-001

<Scapes>Spikes

spikes , , , , .45

45. 003-004

<Scapes>Thickness

1-2 mm thick46

46. 003-002

Capsules

Capsule , ;47

47. 005

Description

Slender to coarse, smooth perennial 20-100 cm high; stems short, sometimes rhizomatous. Leaves erect or in a fan, (5-)10-30(-40) cm, soft, often with maroon pigment, sheath ciliate or entire, narrowing to blade, apically with short-triangular ligule, blade flattened, 1-5(-7) mm wide, margins lustrous, thickened, smooth, less often papillose or scabridulous. Scapes distally terete, 1-2 mm thick, with several strong ribs; spikes ovoid to lance-cylindric or ellipsoid, 1-2 cm, many-flowered, empty bracts several, grading larger into flowering bracts, these broadly ovate to obovate, 5-7 mm, subentire, narrowly rounded, convex, with distinct dorsal area bisected by a distinct, evidently branched midvein. Lateral sepals free, subequilateral, linear-oblanceolate, 4.5-5 mm, keel lacero-ciliate from middle to apex; petals obovate, 4-5 mm; staminodes bearded; anthers ca. 1.5 mm. Capsule 3-5 mm, placentation parietal; seeds cylindric or fusiform, 1-1.5 mm, amber.

Distribution

Andes present, French Guiana present, Planalto of Brazil present, Southern America: Colombia (Colombia present), Trinidad present

Colombia E to French Guiana and Trinidad, S east of the Andes into the Planalto of Brazil

Habit

, perennial ;48

48. 001

Individuals Association

savane PK 20-2l l'Est d'Iracoubo, Cremers 5516 Guyana, Merume Mts., Partang R., Tillett & Boyan 43993 Maripa Soula, Thmuc Humac, de Granville 1410 Guyana, Kaieteur Plateau, Maguire & Fanshawe 23317 Suriname, Kappel-savanna, S of Tafelberg, Kramer & Hekking 2962 Suriname, Wilhelmina Mts., Lucie R., Oost R., Maguire et al. 54133

Lateral sepals

Lateral sepals free, subequilateral, , , ;49

49. 004

Leaves

Leaves , , soft, , ,50

50. 002

Notes

This morphologically and ecologically expressive species should include the extreme X. erythema Maguire & L.B. Smith, as the rhizomal character, the deep red pigmentation and rugulosity of foliage, and the strong ciliation of leaf sheath margins all vary independently through populations in northern South America. The most constant characters remain those of the multicostate, terete scape, venose dorsal area, and the long and distinctively sculpted seed. X. fallax, together with X. jupicai and X. laxifolia comprise the weediest of South American xyrids, quickly coming into wetlands in mechanically disturbed savanna.

Scapes

Scapes , , ;51

51. 003

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