Nomenclature etc. ARALIACEAE. Syn.: Didymopanax morototoni (Aubl.) Decne. & Planch. Trade and local names: amba'y guasu, amba'y, chipa rupa moroti (PY); amba'y guasu (AR); borracho, guitarrero (BO); caixeta, mandioqueira, morototó, marupauva falso, matatauba, mucututu, mandiocai, sambacuim, pixixica, cacheta (BR); candelero, roble, roble blanco, mirasol, chancarro blanco, mano de danta, pie de gallo, marota (MX); sun sun, cafetero, tinajero (VE); pata de gallina, yarumero, yagrumo (CO); platanillo, suntuch (EC); karohoro (GY); sacha-uva, anonilla (PE); guarumo macho (HN); pavo (PA). Not protected under CITES regulations.
Description based on 6 specimens. Tree. Geographic distribution: Mexico and Central America, Caribbean, tropical South America, southern Brazil, and temperate South America.
General. Growth ring boundaries indistinct or absent. Heartwood basically white or grey (pale brownish (dirty)), without streaks. Sapwood colour similar to heartwood colour. Odour indistinct or absent. Density 0.4–0.5 g/cm³.
Vessels. Vessels present. Wood diffuse-porous. Vessels arranged in no specific pattern, in multiples, commonly short (2–3 vessels) radial rows. Vessel outline angular. Two distinct vessel diameter classes absent. Average tangential vessel diameter 94–167 µm; diameter of vessel lumina: medium and large. Average number of vessels/mm² 12–20; vessels per square millimetre few. Average vessel element length 860–1890 µm. Average vessel element length long. Perforation plates simple and scalariform (generally with few bars), with 1–5 bars. Scalariform perforation plates much less frequent than simple perforations. Intervessel pits alternate, average diameter (vertical) 10–12 µm ((vertical diameter; horizontally up to 30 µm)), large, vestured. Intervessel pits typically extended horizontally. Vessel-ray pits with reduced borders or apparently simple, different from intervessel pits, rounded or angular and horizontal to vertical, of uniform size or type, of the same type in adjacent elements, located throughout the ray. Helical thickenings absent. Tyloses in vessels absent. Other deposits in heartwood vessels present, organic deposits only sporadically.
Tracheids and fibres. Vascular or vasicentric tracheids sporadic to absent. Fibres very thin-walled, or of medium wall thickness. Average fibre length 1370–2750 µm. Average fibre length long. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Helical thickenings absent. Fibres exclusively septate, or septate and non-septate. Septate fibres scattered near vessels and rays.
Axial parenchyma. Axial parenchyma present, not banded. Axial parenchyma paratracheal. Paratracheal axial parenchyma scanty. Axial parenchyma as strands. Average number of cells per axial parenchyma strand 3–10. Unlignified parenchyma absent.
Rays. Rays present, 3–5 per tangential mm, multiseriate (also if only few), (2–)3–4(–5) cells wide, of medium width (3–5 seriate). Rays with multiseriate portions as wide as uniseriate portions absent. Aggregate rays absent. Rays of one size. Rays composed of two or more cell types (heterocellular). Heterocellular rays with square and upright cells restricted to marginal rows, mostly 1 marginal row of upright or square cells. Sheath cells absent. Tile cells absent. Perforated ray cells absent. Disjunctive ray parenchyma end walls indistinct or absent.
Storied structures. Storied structure absent.
Secretory structures. Oil and mucilage cells absent. Intercellular canals present, non-traumatic origin, radial type. Laticifers or tanniniferous tubes absent.
Cambial variants. Included phloem absent. Other cambial variants absent.
Mineral inclusions. Crystals not observed. Cystoliths absent. Silica not observed.
Physical and chemical tests. Heartwood not fluorescent. Water extract not fluorescent; basically colourless to brown or shade of brown. Ethanol extract not fluorescent. Colour of ethanol extract colourless to brown or shade of brown. Froth test positive.
Illustrations. • Transverse section. Schefflera morototoni. • Tangential section. Schefflera morototoni. • Radial section. Schefflera morototoni. • Miscellaneous. Schefflera morototoni. Note radial intercellular canals (RIC) and septate fibres. RIC. RIC.
The interactive key allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting specified attributes, summaries of attributes within groups of taxa, and geographical distribution.
Cite this publication as: ‘Richter, H.G., and Dallwitz, M.J. 2000 onwards. Commercial timbers: descriptions, illustrations, identification, and information retrieval. In English, French, German, Portuguese, and Spanish. Version: 25th June 2009. http://delta-intkey.com’.