Xyris guianensis

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Xyris guianensis

Content

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

4.5-5 mm1
1. 003-003-004-003-001-001

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

42
2. 003-003-004-002-001

<<<<Scapes>Spikes>Bracts>Empty bracts>Relative dimensions

smaller and narrower than the flowering ones3
3. 003-003-004-002-002

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

oblong , less keeled, subacute, scarious-margined4
4. 003-003-004-003-001

<<<<Scapes>Spikes>Bracts>Midveins>Shape

strong lance-ovate dorsal area5
5. 003-003-004-001-001

<<<Scapes>Spikes>Bracts>Empty bracts

empty bracts , and grading into them6
6. 003-003-004-002

<<<Scapes>Spikes>Bracts>Floral bracts

these7
7. 003-003-004-003

<<<Scapes>Spikes>Bracts>Midveins

with with strong midvein8
8. 003-003-004-001

<<Capsules>Seeds>Colour

amber9
9. 005-004-003

<<Capsules>Seeds>Length

ca. 0.5 mm10
10. 005-004-002

<<Capsules>Seeds>Shape

ovoid to ellipsoid11
11. 005-004-001

<<Capsules>Valves>Septa

eseptate12
12. 005-003-001

<<Lateral sepals>Anthers>Length

ca. 1 mm13
13. 004-006-001

<<Lateral sepals>Keel>Hairs

papillose to ciliolate above middle14
14. 004-003-002

<<Lateral sepals>Keel>Texture

smooth15
15. 004-003-001

<<Lateral sepals>Petals>Length

ca. 3 mm16
16. 004-004-002

<<Lateral sepals>Petals>Shape

obovate17
17. 004-004-001

<<Lateral sepals>Staminodes>Shape

bearded18
18. 004-005-001

<<Leaves>Blade>Shape

flattened19
19. 002-007-001

<<Leaves>Blade>Width

0.5-1 mm wide20
20. 002-007-002

<<Leaves>Keel>Hairs

often papillose-ciliolate21
21. 002-005-001

<<Leaves>Margins>Colour

pale or dark22
22. 002-008-001

<<Leaves>Margins>Hairs

rarely ciliolate23
23. 002-008-003

<<Leaves>Margins>Margin type

entire24
24. 002-006-001

<<Leaves>Margins>Texture

smooth25
25. 002-008-002

<<Scapes>Ribs>Texture

smooth26
26. 003-002-001

<<Scapes>Shape>Thickness

ca. 0.5 mm thick27
27. 003-001-001

<<Scapes>Spikes>Bracts

bracts few, decussate, , , .28
28. 003-003-004

<<Scapes>Spikes>Colour

pale red-brown29
29. 003-003-003

<<Scapes>Spikes>Length

4-7 mm30
30. 003-003-002

<<Scapes>Spikes>Shape

ellipsoid becoming turbinate31
31. 003-003-001

<Capsules>Length

ca. 2.5 mm32
32. 005-001

<Capsules>Placentation

placentation basal-central33
33. 005-002

<Capsules>Seeds

seeds , , .34
34. 005-004

<Capsules>Valves

valves ;35
35. 005-003

<Habit>Height

5-30 cm high36
36. 001-002

<Habit>Texture

smooth37
37. 001-001

<Lateral sepals>Anthers

anthers .38
38. 004-006

<Lateral sepals>Keel

keel or39
39. 004-003

<Lateral sepals>Length

4-5 mm40
40. 004-002

<Lateral sepals>Petals

petals , ;41
41. 004-004

<Lateral sepals>Shape

oblanceolate42
42. 004-001

<Lateral sepals>Staminodes

staminodes ;43
43. 004-005

<Leaves>Blade

blade , ,44
44. 002-007

<Leaves>Colour

often maroon or red-brown45
45. 002-003

<Leaves>Growth form

in a fan46
46. 002-001

<Leaves>Keel

keel47
47. 002-005

<Leaves>Length

2.5-7 cm48
48. 002-002

<Leaves>Margins

margin , continuous with blade or with auricles,49 margins narrow, incrassate, , or .50
49. 002-006, 50. 002-008

<Leaves>Relative dimensions

about as long as scape sheath, sheath about half as long as blade or less51
51. 002-004

<Scapes>Ribs

ribs52
52. 003-002

<Scapes>Shape

filiform, distally terete or slightly compressed, , ecostate to slightly bicostate53
53. 003-001

<Scapes>Spikes

spikes , , ,54
54. 003-003

Capsules

Capsule , ,55
55. 005

Description

Low, cespitose, smooth, annual 5-30 cm high. Leaves in a fan, 2.5-7 cm, often maroon or red-brown, about as long as scape sheath, sheath about half as long as blade or less, keel often papillose-ciliolate, margin entire, continuous with blade or with auricles, blade flattened, 0.5-1 mm wide, margins narrow, incrassate, pale or dark, smooth or rarely ciliolate. Scapes filiform, distally terete or slightly compressed, ca. 0.5 mm thick, ecostate to slightly bicostate, ribs smooth; spikes ellipsoid becoming turbinate, 4-7 mm, pale red-brown, bracts few, decussate, with strong lance-ovate dorsal area with strong midvein, empty bracts 4, smaller and narrower than the flowering ones and grading into them, these oblong 4.5-5 mm, less keeled, subacute, scarious-margined. Lateral sepals free, subequilateral, oblanceolate4-5 mm, keel smooth or papillose to ciliolate above middle; petals obovate, ca. 3 mm; staminodes bearded; anthers ca. 1 mm. Capsule ca. 2.5 mm, placentation basal-central, valves eseptate; seeds ovoid to ellipsoid, ca. 0.5 mm, amber.

Distribution

S Colombia present, S Venezuela present, Suriname present, to Goias? present
S Colombia E across S Venezuela to Suriname and in contiguous Brazil (to Goias?)

Habit

Low, cespitose, , annual .56
56. 001

Individuals Association

Suriname, Moengo Tapoe ad Grote Zwiebelzwamp, Lanjouw & Lindeman 928 Guyana, Soesdike, A. Cooper 208 Guyana, Kaieteur Plateau, Maguire & Fanshawe 23179 Suriname, Tibiti Savanne near km 5.8, Lanjouw & Lindeman 1852 Guyana, Kaieteur Falls Nat. Park, Hahn et al. 4121

Lateral sepals

Lateral sepals free, subequilateral, , ;57
57. 004

Leaves

Leaves , , , , ,58
58. 002

Notes

This is one of many small species of Xyris that abound in sand savanna at low to high elevations in northern South America, usually in association with such others as X. paraensis, X. savanensis, and X. uleana. Through the range, but more often west, in T.F. Amazonas, Venezuela and in Vaupes, Colombia, as well as in Amazonian Brazil is a more slender-leaved extreme named X. filiscapa but its type differs in no significant way. Some confusion perhaps arises because of another diminutive xyrid, X. tenella, much of which has been identified as X. filiscapa, but which differs in its long-ciliate leaf sheath and its streak-like dorsal area.

Scapes

Scapes , ;59
59. 003