Xyris witsenioides

<<<<Scapes>Spikes>Bracts>Floral bracts>Shape

oblong to obovate, low-carinate and rounded at apex, lacerate with age1

1. 003-004-004-002-001

<<<Habit>Stems>Shape>Texture

stiff2

2. 001-003-001-001

<<<Leaves>Blade>Shape>Width

1-3(-4) mm wide3

3. 002-003-001-001

<<<Leaves>Shape>Ligula>Growth form

erect4

4. 002-002-001-002

<<<Leaves>Shape>Ligula>Length

1-2 mm5

5. 002-002-001-003

<<<Leaves>Shape>Ligula>Shape

triangular6

6. 002-002-001-001

<<<Scapes>Spikes>Bracts>Empty bracts

several empty ones, the lowest small, grading into flowering ones7

7. 003-004-004-001

<<<Scapes>Spikes>Bracts>Floral bracts

these8

8. 003-004-004-002

<<Capsules>Seeds>Colour

amber9

9. 005-004-003

<<Capsules>Seeds>Length

ca. 1-1.3 mm10

10. 005-004-002

<<Capsules>Seeds>Shape

fusiform11

11. 005-004-001

<<Capsules>Valves>Septa

with complete septa12

12. 005-003-001

<<Habit>Stems>Shape

elongate-ascending, much-branched from base, branches enfolded by tightly imbricate rows of leaves and old sheath bases, forming plates (the whole forming dense domes or cushions)13

13. 001-003-001

<<Lateral sepals>Anthers>Length

1.5-1.7 mm14

14. 004-005-001

<<Lateral sepals>Petals>Length

3-6 mm15

15. 004-003-002

<<Lateral sepals>Petals>Shape

broadly obovate to suborbicular16

16. 004-003-001

<<Lateral sepals>Shape>Hairs

ciliate17

17. 004-002-001

<<Lateral sepals>Staminodes>Shape

bearded18

18. 004-004-001

<<Leaves>Blade>Shape

flattened, , sometimes falciform19

19. 002-003-001

<<Leaves>Margins>Hairs

rarely ciliolate20

20. 002-004-002

<<Leaves>Margins>Texture

smooth or scaberulous-papillose21

21. 002-004-001

<<Leaves>Margins>Veins

surface finely but strongly multiveined surface22

22. 002-004-003

<<Leaves>Shape>Ligula

with a ligule of23

23. 002-002-001

<<Scapes>Ribs>Hairs

rarely ciliolate24

24. 003-003-003

<<Scapes>Ribs>Rib number

1 (-2 or more)25

25. 003-003-001

<<Scapes>Ribs>Texture

smooth or scaberulous26

26. 003-003-002

<<Scapes>Spikes>Bracts

bracts in a spiral, thin, without evident dorsal area, ,27

27. 003-004-004

<<Scapes>Spikes>Colour

olive-brown or red-brown28

28. 003-004-003

<<Scapes>Spikes>Length

0.7-1.4 cm long29

29. 003-004-002

<<Scapes>Spikes>Shape

ellipsoid to obovoid30

30. 003-004-001

<Capsules>Length

3.5-4 mm31

31. 005-001

<Capsules>Placentation

placentation axile32

32. 005-002

<Capsules>Seeds

seeds , , .33

33. 005-004

<Capsules>Valves

valves ;34

34. 005-003

<Habit>Height

(12-)20-60 cm high35

35. 001-002

<Habit>Stems

stems .36

36. 001-003

<Habit>Texture

smooth37

37. 001-001

<Lateral sepals>Anthers

anthers .38

38. 004-005

<Lateral sepals>Length

ca. 5-7 mm39

39. 004-001

<Lateral sepals>Petals

petals , ;40

40. 004-003

<Lateral sepals>Shape

obtuse, keel subentire to , lacerate with age41

41. 004-002

<Lateral sepals>Staminodes

staminodes ;42

42. 004-004

<Leaves>Blade

blade ,43

43. 002-003

<Leaves>Length

5-20 cm44

44. 002-001

<Leaves>Margins

margin thin, , , .45

45. 002-004

<Leaves>Shape

sheath eciliate, fully as long as blade, keeled, mostly castaneous, apically46

46. 002-002

<Scapes>Ribs

ribless or with ribs, these ()47

47. 003-003

<Scapes>Shape

distally subterete to slightly compressed and oval or oblong-elliptic48

48. 003-001

<Scapes>Spikes

spikes , , , .49

49. 003-004

<Scapes>Width

0.7-1 mm wide50

50. 003-002

Capsules

Capsule , ,51

51. 005

Citation

F. Oliver 1887: p. 285. – In: Trans. Linn. Soc. London. pl. 50, fig. 915

Description

Densely cespitose, smooth perennial, (12-)20-60 cm high; stems elongate-ascending, much-branched from base, branches enfolded by tightly imbricate rows of leaves and old sheath bases, forming stiff plates (the whole forming dense domes or cushions). Leaves mostly ascending, 5-20 cm, sheath eciliate, fully as long as blade, keeled, mostly castaneous, apically with a triangularerect ligule of 1-2 mm, blade flattened, 1-3(-4) mm wide, sometimes falciform, margin thin, smooth or scaberulous-papillose, rarely ciliolate, surface finely but strongly multiveined surface. Scapes distally subterete to slightly compressed and oval or oblong-elliptic, 0.7-1 mm wide, ribless or with 1 (-2 or more) ribs, these smooth or scaberulous (rarely ciliolate); spikes ellipsoid to obovoid, 0.7-1.4 cm long, olive-brown or red-brown, bracts in a spiral, thin, without evident dorsal area, several empty ones, the lowest small, grading into flowering ones, these oblong to obovate, low-carinate and rounded at apex, lacerate with age. Lateral sepals free, subequilateral, ca. 5-7 mm, obtuse, keel subentire to ciliate, lacerate with age; petals broadly obovate to suborbicular, 3-6 mm; staminodes bearded; anthers 1.5-1.7 mm. Capsule 3.5-4 mm, placentation axile, valves with complete septa; seeds fusiform, ca. 1-1.3 mm, amber.

Distribution

Bolivar present, S Amazonas present, SE Guyana present, Southern America: Venezuela (Venezuela present), contiguous high-altitude Brazil present

S Amazonas and Bolivar, Venezuela E to SE Guyana and in contiguous high-altitude Brazil.

Habit

Densely cespitose, perennial, ;52

52. 001

Individuals Association

Guyana, N slope Mt. Roraima, J. Renz 14270 Guyana, Mt. Roraima Expedition, McConnell & Quelch 658 Guyana, Mt. Roraima Expedition, Quelch & McConnell 95 Guyana, Mt. Roraima, N.J. Abbensetts 20

Lateral sepals

Lateral sepals free, subequilateral, , ;53

53. 004

Leaves

Leaves mostly ascending, , ,54

54. 002

Notes

Perhaps the most distinctive of the Guiana Xyris in habit, on the basis of placentation and leaf appearing to be one of the primitive mem- bers and part of a complex of species best represented along the tepuis of southern Venezuela.

Scapes

Scapes , , ;55

55. 003

Primary tabs

Content