Urera

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Urera

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<<Leaves>Stipules>Shape

connate1
1. 002-001-001

<<Pistillate flowers>Stigma>Shape

penicillate-capitate2
2. 005-002-001

<<Pistillate flowers>Tepals>Shape

basally connate3
3. 005-001-002

<<Pistillate flowers>Tepals>Tepal number

44
4. 005-001-001

<<Staminate flowers>Stamens>Stamen number

4-55
5. 004-002-001

<<Staminate flowers>Tepals>Shape

basally connate6
6. 004-001-002

<<Staminate flowers>Tepals>Tepal number

4-57
7. 004-001-001

<Akenes>Perianth

partly enveloped by a slightly enlarged, juicy perianth8
8. 006-001

<Habit>Hairs

(usually) with stinging hairs or prickles9
9. 001-001

<Inflorescences>Flowers

flowers pedicellate or sessile.10
10. 003-002

<Inflorescences>Shape

paniculate, dichotomously or more or less irregularly branched11
11. 003-001

<Leaves>Blade

blade pinnately veined.12
12. 002-002

<Leaves>Stipules

stipules ;13
13. 002-001

<Pistillate flowers>Stigma

stigma , persistent on the hooked apex of the fruit.14
14. 005-002

<Pistillate flowers>Tepals

with , equal or unequal, tepals15
15. 005-001

<Staminate flowers>Stamens

stamens .16
16. 004-002

<Staminate flowers>Tepals

with , tepals17
17. 004-001

Akenes

Achene .18
18. 006

Description

Tree(lets) shrubs or subshrubs, usually dioecious, (usually) with stinging hairs or prickles. Leaves in spirals (to distichous); stipules connate; blade pinnately veined. Inflorescences paniculate, dichotomously or more or less irregularly branched, with the flowers solitary or in glomerules; flowers pedicellate or sessile. Staminate flowers with 4-5, basally connate tepals; stamens 4-5. Pistillate flowers with 4, equal or unequal, basally connate tepals; stigma penicillate-capitate, persistent on the hooked apex of the fruit. Achene partly enveloped by a slightly enlarged, juicy perianth.

Distribution

Africa present, Guianas present, Neotropics present present
Mainly in Africa and the Neotropics approx. 20 species; in the Neotropics 5-8 species; in the Guianas 3 species.

Habit

Tree(lets) shrubs or subshrubs, usually dioecious, .19
19. 001

Inflorescences

Inflorescences , with the flowers solitary or in glomerules;20
20. 003

Leaves

Leaves in spirals (to distichous);21
21. 002

Notes

Based on Bonsen & ter Welle (1984): U. baccijera (Panama), U. caracasana (Colombia and Argentina), U. laciniata (Surinam).

Pistillate flowers

Pistillate flowers ;22
22. 005

Staminate flowers

Staminate flowers ;23
23. 004

Wood

Growth rings absent. Vessels diffuse, mainly solitary and sometimes in clusters of 2-4, round to oval, 2-8 per sq. mm, diameter 100-180 μm. Vessel-member length: 180-270 μm. Perforations simple. Intervascular pits alternate, polygonal, 9-18 μm. Vessel-ray and vessel-parenchyma pits as the intervascular pits. Thin-walled tyloses present or absent.
Rays only 2-4-seriate (= 40-50 μm), 1-3 per mm, up to several mm high. Heterogeneous, composed of square and upright cells, sometimes partly unlignified. Sheath cells common. Druses sometimes present.
Parenchyma paratracheal vasicentric. Strands of 2-4 cells. Apotracheal parenchyma mainly unlignified, occuring as islands or bands in transverse sections, containing druses, often storied.
Fibres non-septate, lumen 12-24 μm, walls 3-6 μm, often storied. Pits simple, on radial and tangential walls. Length: 825-1255 μm.