Xyris involucrata

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

red-brown1

1. 003-004-003-004-003-002

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

often villosulous2

2. 003-004-003-004-003-001

<<<<Scapes>Spikes>Bracts>Floral bracts>Length

4-5 mm3

3. 003-004-003-004-002

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

rhombic to oblong-obovate4 tips acute or short-acuminate, , back shallowly convex with a large, dorsal area5

4. 003-004-003-004-001, 5. 003-004-003-004-003

<<<<Scapes>Spikes>Bracts>Outer bracts>Hairs

ciliate6

6. 003-004-003-002-001

<<<Lateral sepals>Keel>Hairs>Colour

reddish7

7. 004-002-001-001

<<<Leaves>Margins>Hairs>Colour

white8

8. 002-006-001-001

<<<Scapes>Margins>Hairs>Colour

white9

9. 003-003-002-001

<<<Scapes>Spikes>Bracts>Bract number

numerous10

10. 003-004-003-001

<<<Scapes>Spikes>Bracts>Floral bracts

these firm, , ,11

11. 003-004-003-004

<<<Scapes>Spikes>Bracts>Inner bracts

inner empty bracts abruptly smaller, grading to slightly shorter flowering bracts12

12. 003-004-003-003

<<<Scapes>Spikes>Bracts>Outer bracts

outer ones forming a leafy involucre, these bracts with keel and margins13

13. 003-004-003-002

<<Capsules>Seeds>Colour

dark amber14

14. 005-004-003

<<Capsules>Seeds>Length

0.5-0.6 mm15

15. 005-004-002

<<Capsules>Seeds>Shape

ellipsoid-cylindric16

16. 005-004-001

<<Capsules>Valves>Septa

eseptate17

17. 005-003-001

<<Lateral sepals>Anthers>Length

ca. 1.5 mm18

18. 004-005-001

<<Lateral sepals>Keel>Hairs

-ciliate from below middle to apex19

19. 004-002-001

<<Lateral sepals>Petals>Length

4-5 mm20

20. 004-003-002

<<Lateral sepals>Petals>Shape

elliptic21

21. 004-003-001

<<Lateral sepals>Staminodes>Shape

bearded22

22. 004-004-001

<<Leaves>Base>Colour

castaneous23

23. 002-004-001

<<Leaves>Base>Ligula

ligule lacking24

24. 002-004-002

<<Leaves>Blade>Shape

flattened25

25. 002-005-001

<<Leaves>Margins>Hairs

-ciliate26

26. 002-006-001

<<Leaves>Sheaths>Relative dimensions

at least as long as blade27

27. 002-003-001

<<Scapes>Margins>Hairs

-ciliate28

28. 003-003-002

<<Scapes>Margins>Shape

winged29

29. 003-003-001

<<Scapes>Spikes>Bracts

bracts in a tight spiral, , , .30

30. 003-004-003

<<Scapes>Spikes>Length

0.5-1 cm31

31. 003-004-002

<<Scapes>Spikes>Shape

hemispheric to broadly ovoid or subglobose32

32. 003-004-001

<Capsules>Length

ca. 2 mm33

33. 005-001

<Capsules>Placentation

placentation basal34

34. 005-002

<Capsules>Seeds

seeds , , .35

35. 005-004

<Capsules>Valves

valves ;36

36. 005-003

<Habit>Height

20-60 cm high37

37. 001-001

<Habit>Stems

stem short.38

38. 001-002

<Lateral sepals>Anthers

anthers .39

39. 004-005

<Lateral sepals>Keel

keel40

40. 004-002

<Lateral sepals>Length

ca. 3 mm41

41. 004-001

<Lateral sepals>Petals

petals , ;42

42. 004-003

<Lateral sepals>Staminodes

staminodes ;43

43. 004-004

<Leaves>Base

base , ,44

44. 002-004

<Leaves>Blade

blade ,45

45. 002-005

<Leaves>Growth form

in a fan46

46. 002-001

<Leaves>Length

10-30 cm47

47. 002-002

<Leaves>Margins

margins .48

48. 002-006

<Leaves>Sheaths

sheath , entire, keeled49

49. 002-003

<Scapes>Margins

margins , ;50

50. 003-003

<Scapes>Shape

distally flattened51

51. 003-001

<Scapes>Spikes

spikes , ,52

52. 003-004

<Scapes>Width

3-4 mm wide53

53. 003-002

Capsules

Capsule , ,54

54. 005

Description

Short-lived, mostly tufted, smoothish herbs, 20-60 cm high; stem short. Leaves in a fan, 10-30 cm, sheath at least as long as blade, entire, keeled, base castaneous, ligule lacking, blade flattened, margins white-ciliate. Scapes rigid, distally flattened, 3-4 mm wide, margins winged, white-ciliate; spikes hemispheric to broadly ovoid or subglobose, 0.5-1 cm, bracts numerous in a tight spiral, outer ones forming a leafy involucre, these bracts with keel and margins ciliate, inner empty bracts abruptly smaller, grading to slightly shorter flowering bracts, these firm, rhombic to oblong-obovate, 4-5 mm, tips acute or short-acuminate, often villosulous, back shallowly convex with a large, red-brown dorsal area. Lateral sepals free, subequilateral, curved, ca. 3 mm, blunt, keel reddish-ciliate from below middle to apex; petals elliptic, 4-5 mm; staminodes bearded; anthers ca. 1.5 mm. Capsule ca. 2 mm, placentation basal, valves eseptate; seeds ellipsoid-cylindric, 0.5-0.6 mm, dark amber.

Distribution

Guyana present, S Venezuela present, SE Colombia present, contiguous Brazil present

SE Colombia E through S Venezuela to Guyana and in contiguous Brazil.

Habit

Short-lived, mostly tufted, smoothish herbs, ;55

55. 001

Individuals Association

Guyana, Pakaraima Mts., Mt. Mem- baru, Maas & Westra 4290 Guyana, Membaru Cr., upper Mazaruni R., A.S. Pinkus 22 Guyana, Kamarang R., Wenamu 'frail, summit of Holi-tepui, Maguire & Fanshawe 32497 Guyana, Kaieteur Pla- teau, 3 May 1944, Maguire & Fanshawe 23175 Guyana, Kaieteur Nat. Park, near air- strip, Pipoly 9819 Guyana, Pakaraima Mts.,Kako Amerindian village, Kako R., Maas & Westra 4391

Lateral sepals

Lateral sepals free, subequilateral, curved, , blunt, ;56

56. 004

Leaves

Leaves , , ,57

57. 002

Notes

The only species of Xyris in the Guianas to have a spreading invo- lucre of leafy bracts to twice as long as the heads are wide, and actually a part of a leafy-bracted complex more typical of the Brazilian Planalto. Unusual for most Xyris of northern South America but characteristic for this complex, many corollas are presented simultaneously on a spike, thus contributing much to the attractiveness of such plants.

Scapes

Scapes rigid, , ,58

58. 003

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