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Nomenclature etc. FABACEAE-FABOIDEAE. Trade and local names: pau violeta, jacarandá violeta, miolo de negro (BR).
Description based on 5 specimens. Small tree. Geographic distribution: tropical South America (northeastern Brazil).
General. Growth ring boundaries distinct or indistinct or absent. Heartwood basically brown, purple; with streaks. Sapwood colour distinct from heartwood colour (pale yellow). Odour indistinct or absent. Density 0.92–1.08 g/cm³.
Vessels. Wood semi ring porous to diffuse porous. Vessels arranged in no specific pattern, in multiples, commonly in short (2–3 vessels) radial rows or in radial rows of 4 or more. Two distinct vessel diameter classes absent. Average tangential vessel diameter (45–)65–95(–115) µm. Average number of vessels/mm² 19–23(–28). Perforation plates simple. Intervessel pits alternate, average diameter (vertical) 5–7 µm, pits vestured. Vessel-ray pits with distinct borders, similar to intervessel pits. Tyloses absent. Other deposits present.
Tracheids and fibres. Fibres very thick-walled. Fibre pits mainly restricted to radial walls, simple to minutely bordered. Fibres non-septate.
Axial parenchyma. Axial parenchyma banded. Bands marginal (or seemingly marginal) (often discontinuous). Bands fine. Axial parenchyma apotracheal, or paratracheal. Apotracheal axial parenchyma diffuse, or diffuse-in-aggregates. Paratracheal axial parenchyma scanty, or vasicentric, or aliform. Aliform parenchyma of the winged type. Axial parenchyma as strands. Average number of cells per strand: 2–3.
Rays. Rays 8–13 per tangential mm, multiseriate, 1–2(–3) cells wide. Height of large rays up to 500 µm. Rays composed of a single cell type (homocellular), or two or more cell types (heterocellular) (only few); homocellular ray cells procumbent. Heterocellular rays with square and upright cells restricted to marginal rows, mostly 1 marginal row of upright or square cells.
Storied structures. Storied structure present, all rays storied, axial parenchyma storied, vessel elements storied, fibres storied. Arrangement of tiers regular, or irregular. Number of ray tiers per axial millimetre 5–6.
Secretory structures. Intercellular canals absent.
Mineral inclusions. Crystals present, prismatic, located in axial parenchyma cells. Crystal-containing axial parenchyma cells chambered. Silica not observed.
Physical and chemical tests. Froth test negative.
Illustrations. • Macroscopic images. transverse (ca. 10x). radial (natural size). tangential (natural size). • Transverse section. • Tangential section. • Radial section.
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: 9th April 2019. delta-intkey.com’.
