Pourouma

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Pourouma

Content

<<<Fruits>Perianth>Outer layer>Colour

black(ish)1
1. 006-002-002-001

<<<Inflorescences>Flowers>Head>Position

terminal2
2. 003-001-001-001

<<<Inflorescences>Flowers>Head>Shape

globose3
3. 003-001-001-002

<<Fruits>Perianth>Outer layer

the outer layer of which turning at maturity4
4. 006-002-002

<<Fruits>Perianth>Texture

fleshy5
5. 006-002-001

<<Inflorescences>Flowers>Head

, heads6
6. 003-001-001

<<Perianth>Stigma>Shape

(sub)peltate or knob-like7
7. 005-002-001

<<Stipule scars>Blade>Veins

venation pinnate to sub palmate.8
8. 002-001-001

<<Tepals>Stamens>Stamen number

(3 or) 49
9. 004-003-001

<Fruits>Cotyledons

cotyledons thick.10
10. 006-005

<Fruits>Endosperm

endosperm absent;11
11. 006-004

<Fruits>Length

1-2 cm long12
12. 006-001

<Fruits>Perianth

enclosed by the enlarged, perianth,13
13. 006-002

<Fruits>Pseudodrupes

fruit and perianth constitute a "pseudodrupe"14
14. 006-003

<Habit>Internodes

internodes solid.15
15. 001-002

<Habit>Stilt-roots

often with stilt-roots16
16. 001-001

<Inflorescences>Flowers

with the flowers ± disperse or (in staminate inflorescences) in17
17. 003-001

<Perianth>Shape

tubular18
18. 005-001

<Perianth>Stigma

stigma .19
19. 005-002

<Stipule scars>Blade

blade basally attached, palmately incised or entire,20
20. 002-001

<Tepals>Shape

free or connate21
21. 004-002

<Tepals>Stamens

stamens , free.22
22. 004-003

<Tepals>Tepal number

(3 or) 423
23. 004-001

Common Name

English: boroma, bospapaja, granboesipapaja, poeroema, yarayara

Description

Trees, terrestrial, often with stilt-roots; internodes solid. Scars of the stipules transverse; blade basally attached, palmately incised or entire, venation pinnate to sub palmate. Inflorescences branched (or unbranched and subumbellate), with the flowers ± disperse or (in staminate inflorescences) in terminal, globose heads, ebracteate or sometimes bracteate. Tepals of the staminate flowers (3 or) 4, free or connate; stamens (3 or) 4, free. Perianth of the pistillate flower tubular; stigma (sub)peltate or knob-like. Fruit large (1-2 cm long), dry, enclosed by the enlarged, fleshy perianth, the outer layer of which turning black(ish) at maturity, fruit and perianth constitute a "pseudodrupe", endosperm absent; cotyledons thick.

Distribution

Guianas present, Neotropics present
Neotropics 26 species; in the Guianas 10 species known and P. bolivarensis expected.

Fruits

Fruit large (), dry, , ,24
24. 006

Habit

Trees, terrestrial, ;25
25. 001

Inflorescences

Inflorescences branched (or unbranched and subumbellate), , ebracteate or sometimes bracteate.26
26. 003

Perianth

Perianth of the pistillate flower ;27
27. 005

Stipule scars

Scars of the stipules transverse;28
28. 002

Tepals

Tepals of the staminate flowers , ;29
29. 004

Wood

Vessels diffuse, solitary (55-95%) and in radial multiples and irregular clusters of 2-3, round to oval, 1-6 per sq. mm, diameter 125-255 μm. Vessel-member length: 475-850 μm. Perforations simple. Intervascular pits alternate, round or polygonal, 10-20 μm. Vessel-ray and vessel- parenchyma pits larger, often elongated, half-bordered. Thin-walled tyloses present or absent.
Rays uniseriate and 2-5-seriate, 4-9 per mm, up to 450-1280 μm high. Heterogeneous, composed of procumbent, square and upright cells, with uniseriate margins of 1-6 rows, occasionally vertically compound. Rhom- bic crystals sometimes present. Radial latex tubes observed in P. melinonii.
Parenchyma paratracheal, variable, vasicentric and aliform to confluent and even banded. Bands regular, wavy, 2-3 per mm, sometimes apotracheal terminal bands. Strands of 5-6 cells. Rhombic crystals common.
Fibres non-septate, lumen 18-36 μm, walls 1-4 μm. Pits simple, small, mainly on the radial walls. Gelatinous fibres present or absent. Length: 940-1725 μm. F/V ratio: 1.6-2.7.

Wood observation species

P. guianensis, P. melinonii