IAWA Hardwood Feature List
Definitions and Illustrations Features 40-59.
Numbered photographs from: IAWA Committee. 1989. IAWA List of Microscopic Features for Hardwood Identification. IAWA Bulletin n.s. 10(3): 219-332.
Photographs without numbers are associated with the InsideWood website hosted by N.C. State University Libraries.
http://insidewood.lib.ncsu.edu/search
Photographs copyright of the individual photographers credited.
Order form at International Association of Wood Anatomists Web Site http://bio.kuleuven.be/sys/iawa
Slide Set Assembled by E.A.Wheeler
MEAN TANGENTIAL DIAMETER OF VESSEL LUMINA
40. 41. 42. 43.
< 50 m 50-100 m 100-200 m > 200 m
Photo by Frederic Lens
Procedure: Use transverse (cross) sections. The tangential diameter of the vessel lumina, excluding the wall, is measured at the widest part of the opening. In ring-porous woods and woods with two distinct diameter classes, only measure the larger size classes.
Mean Tangential Diameter of Vessel Lumina
40. < 50 m
Gaultheria strigosa (Ericaceae)
41. 50 - 100 m
Diospyros cooperi (Ebenaceae)
42. 100 - 200 m
(Sapotaceae)
Autranella congolensis
43. > 200 m
(Marcgraviaceae)
Norantea guianensis All Photos by Frederic Lens
VESSELS PER SQUARE MILLIMETRE 46. < 5 vessels per square millimetre 47. 5-20 vessels per square millimetre 48. 20-40 vessels per square millimetre 49. 40-100 vessels per square millimetre 50. > 100 vessels per square millimetre
Procedure: All vessels are counted as individuals, e.g. a radial multiple of four would be counted as four vessels. Of vessels that are partially in the field of view only 50% are counted.
6 7 2 3 4 5 1 11 12 9 13 20 NO
Photo by Frederic Lens
14 8 16 15 17 18 19 10
Feature 45. Vessels of two distinct diameter classes, wood not ring-porous = woods with a bimodal distribution of tangential diameters of vessel lumina.
Serjania subdentata (Sapindaceae) I.W. Bailey, Bailey-Wetmore Laboratory of Plant Anatomy and Morphology, Harvard University
Pueraria lobata (Leguminosae - Papilionoideae). FFPRI,Tsukuba, Japan
TYLOSES AND DEPOSITS IN VESSELS
Feature 56. Tyloses common = outgrowths from an adjacent ray or axial parenchyma cell through a pit in a vessel wall, partially or completely blocking the vessel lumen, and of common occurrence.
Anacardium occidentale (Anacardiaceae) E.A. Wheeler
Robinia pseudoacacia (LeguminosaePapilionoideae) E.A. Wheeler
Feature 56. Tyloses common
Northia seychellana (Sapotaceae) F. Lens Maclura tricuspidata (Moraceae) A.M.W. Mennega
Feature 57. Tyloses sclerotic = tyloses with thick, multilayered, lignified walls.
Cantleya corniculata (Stemonuraceae) K.Ogata
Feature 58. Gums and other deposits in heartwood vessels
Swietenia mahagoni (Meliaceae) Chalk deposits (arrows) L.Y.T. Westra
Pericopsis angolensis (LeguminosaePapilionoideae) M.E. Bakker
Feature 59. Wood vesselless = wood without vessel elements, composed only of imperforate tracheary elements and parenchyma
Trochodendron araliodes (Trochodendraceae) I.W. Bailey, Bailey-Wetmore Laboratory of Plant Anatomy and Morphology, Harvard University
