IAWA Journal, Vol. 32 (3), 2011: 383–393 IDENTIFICATION OF JAPANESE SPECIES OF EVERGREEN QUERCUS AND LITHOCARPUS (FAGACEAE) Shuichi Noshiro1 and Yuka Sasaki2 SUMMARY To identify archaeological oak woods with very large vessels (> 200 µm), the wood structure of eleven species of evergreen Quercus and Litho- carpus from Japan were studied. Species groups could be identified by the size and frequency of vessels and the ray structure. Quercus phil- lyraeoides of subg. Sclerophyllodrys had semi-ring-porous wood with small (< 100 µm on average), numerous vessels, and aggregate rays. Two species of Lithocarpus had aggregate to semi-compound rays that came to be divided by the development of vertical masses of fusiform cells. Among species of Quercus subg. Cyclobalanopsis, Q. gilva, Q. hondae, and Q. miyagii had very large vessels with a maximum vessel diameter over 200 µm. Within the species groups, individual species could not be identified just from wood structure, butQ. gilva could be distinguished when the distribution ranges of species were considered. The vertical splitting of semi-compound rays in Lithocarpus with the formation of a vertical wedge of fusiform cells differed from the ray development so far reported in Fagaceae or other taxa that have broad rays, and occurred only in the subgenus Pasania. Key words: Fagaceae, identification, Japan,Lithocarpus , Quercus subg. Cyclobalanopsis, wood structure. INTRODUCTION When rice cultivation was introduced into Japan around the beginning of the Yayoi period (c. 500 years BC), wood of evergreen oaks was selected to make various tools for agriculture and processing such as hoes, spades, mallets, and axe handles (Ito & Yamada 2011). While identifying materials of wooden tools of the subsequent, early Kofun period (late third to mid seventh centuries AD), the authors noticed that oak wood with very large vessels (> 200 µm) was exclusively selected for hoes and spades. To identify this distinct wood, the wood structure of Japanese species of evergreen Quer- cus and Lithocarpus was studied. These include two species of Lithocarpus, L. edulis (Makino) Nakai and L. glaber (Thunb. ex Murray) Nakai, eight species of Quercus subg. Cyclobalanopsis, Q. acuta Thunb., Q. gilva Blume, Q. glauca Thunb., Q. hondae Makino, Q. miyagii Koidz., Q. myrsinifolia Blume, Q. salicina Blume, and Q. sessilifolia Blume, and one species of Quercus subg. Sclerophyllodrys, Q. phillyraeoides A. Gray 1) Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan [E-mail: [email protected]]. 2) Paleo Labo Co., Ltd., Shimomae 1-13-22, Toda, Saitama 355-0016, Japan. Downloaded from Brill.com09/29/2021 03:03:38PM via free access 384 IAWA Journal, Vol. 32 (3), 2011 (Table 1; Ohba 2006). Most of the studied species grow southwestward from middle Honshu to Kyushu, some growing also in the Nansei islands (Fig. 1). Two species have narrower distribution ranges than other species, Q. hondae in southwestern Shikoku and Kyushu and Q. miyagii in Nansei islands. The wood structure of Japanese species of oaks has been studied by Onaka (1939) and Shimaji (1954, 1956, 1959). To identify archaeological woods, Onaka (1939) compared features of vessels and rays of six species of subg. Cyclobalanopsis and one species of Lithocarpus that grew in the Yamato district around an archaeological site in middle Honshu. He found that the size and arrangement of vessels, the size of axial parenchyma cells, and the occurrence and size of prismatic crystals in axial parenchyma can be used to distinguish species. However, his observation of wood anatomical features is presented only in a table without any information about the specimens studied, and it is not known how much of the species-level variation is reflected in his observations. To clarify systematic patterns in the wood structure of Fagaceae, Shimaji (1954, 1956, 1959) studied the wood structure of Japanese species of Quercus and Lithocarpus and Table 1. Japanese species of evergreen Quercus and Lithocarpus, details of studied speci- mens, and the ranges and means (in parentheses) of their vessel features. Sp = specimen number, TVD = tangential vessel diameter. Species Sp Latitude Longitude Stem TVD Maximum Vessel Vessel (°N) (°E) diam. (µm) TVD frequency area ratio (cm) (µm) (no./mm2) (%) Lithocarpus L. edulis (Makino) Nakai 7 26.8–33.2 128.3–131.5 10–29 77–128 134–184 1.4–5.6 1.4–6.3 (101) (153) (3.9) (3.7) L. glaber (Thunb. ex Murray) Nakai 3 31.9–33.1 131.2–132.7 16–28 101–115 168–200 4.1–5.8 5.7–6.6 (110) (183) (5.2) (6.3) Quercus subg. Cyclobalanopsis Q. acuta Thunb. 24 30.3–35.2 129.2–140.2 6–96 76–112 120–193 2.8–8.1 2.4–9.6 (95) (155) (4.9) (4.5) Q. gilva Blume 13 31.5–35.2 130.5–140.1 8–57 87–156 141–254 2.7–5.5 3.9–12.1 (127) (210) (3.9) (6.5) Q. glauca Thunb. 18 31.7–35.2 130.3–138.2 10–65 53–117 90–188 2.5–5.9 0.8–6 (95) (157) (4.5) (4.1) Q. hondae Makino 3 31.9–31.9 131.1–131.2 9–41 111–145 203–252 2.7–5.6 3.8–6.3 (123) (229) (3.7) (5.4) Q. miyagii Koidz. 4 24.4–27.8 123.8–128.9 12.5–30 112–149 179–233 3.4–6.8 4.9–8.7 (128) (197) (4.7) (7.3) Q. myrsinifolia Blume 7 31.9–35.2 130.5–140.1 8–75 91–113 147–196 2.3–8.5 2.3–7.4 (101) (171) (5.1) (5.3) Q. salicina Blume 24 28.3–35.3 129.2–136.4 8–76 61–121 114–200 2.2–9.6 2.1–6.9 (92) (150) (5.1) (4.2) Q. sessilifolia Blume 14 31.8–35.0 130.5–136.2 10–39 70–140 119–223 3.7–7.6 2.8–9.7 (99) (167) (5.2) (5.1) Quercus subg. Sclerophyllodrys Q. phillyraeoides A.Gray 7 30.3–34.4 130.4–136.9 5.5–33 46–82 76–163 6.4–22.1 2.6–4.3 (60) (121) (10.8) (3.5) Downloaded from Brill.com09/29/2021 03:03:38PM via free access Noshiro & Sasaki — Japanese Quercus and Lithocarpus 385 Figure 1. Distribution of studied specimens and the distribution range of Quercus gilva. The northern limit of Q. acuta shows the northern limit of evergreen Quercus and Lithocarpus species in Japan (distribution ranges modified from Kurata 1964). presented a key to identify these species from wood structure. In the key for the species with radial-porous wood, the colour of wood was used as the first feature to distinguish groups, and the arrangement of vessels and the occurrence of prismatic crystals in chambered or non-chambered cells were used in the following keys, and the vessel size was used only in a minor key. The colour of wood is not applicable to archaeological woods, and preliminary observation showed that some of the features used in the key, such as the number of vessel rows and the chambering of crystalliferous cells, are too variable to be used as good criteria. Thus, we studied the wood specimens deposited at TWTw, Tsukuba, Japan to clarify the species-level variation in wood structure among Japanese species of Fagaceae with radial-porous wood. In this paper, to conform to the terms used by Shimaji (1962) to describe the onto genetic trends in ray development of Fagaceae where 2–3-seriate narrow rays aggregate and become fused to form broad rays, we refer to broad rays as compound rays and to rays that are partly aggregate and partly compound as semi-compound rays. Downloaded from Brill.com09/29/2021 03:03:38PM via free access 386 IAWA Journal, Vol. 32 (3), 2011 Materials AND METHODS Among specimens of Lithocarpus and evergreen Quercus deposited at TWTw, 124 specimens with records of the stem diameter and localities were used (Table 1). All the specimens were obtained from the trunk at around breast height avoiding junctions of branches. The diameter was measured at the height of collection with bark from two directions and was averaged. For four specimens without records of the stem diameter, the diameters were estimated from the radius of the wood specimens (indicated with asteriks). To supplement the lack of available specimens, a branch wood specimen was also studied for Q. hondae. The specimen numbers for each species are as follows: Lithocarpus edulis: 16054, 18896, 19332, 19367, 20154, 20973, 21240. L. glaber: 18908, 21255, 23494. Quercus acuta: 9315*, 15659, 15852, 16025, 16951, 18813, 19013, 19058, 19548, 19600, 20156, 20264, 21011, 21121, 21210, 22611, 22654, 23471, 23641, 23719, 24010, 24045, 25318, 25412. Q. gilva: 414, 811*, 9317*, 13280, 17750*, 18794, 18899, 21248, 22621, 22624, 25138, 25233, TI-4813 (a microscopic slide with a collection record). Q. glauca: 17570, 18395, 18790, 18863, 18883, 19046, 20193, 21254, 21693, 22546, 23415, 23686, 24035, 25151, 25260, 25261, 25330, 25478. Q. hondae: 17749 (both stem and brach wood specimens), 25272. Q. miyagii: 12867, 17391, 23286, 23351. Q. myrsinifolia: 3344*, 18857, 18906, 21645, 22625, 23416, 25293 Q. salicina: 16089, 16143, 16977, 18475, 18898, 18907, 19089, 19449, 19543, 19634, 20194, 20250, 21203, 21270, 21559, 21633, 22541, 23515, 23597, 23752, 24013, 25316, 25366, 25415. Q. sessilifolia: 18840, 18895, 18904, 19095, 19097, 20204, 21238, 21600, 21709, 22632, 23487, 25156, 25282, 25354. Q. phillyraeoides: 15495, 15516, 16125, 19131, 23697, 23750, 25432. Quantitative features of vessels were obtained by image analysis of transverse sections.