Agonandra brasiliensis, ivory wood, is a tree species from the Brazilian cerrado with a bark featuring a thick cork layer. The present study aimed to describe the cellular features and chemical composition of this cork. The cork was investigated regarding cellular structure and biometry, as well as summative chemical composition. The results were compared with those of corks from Quercus suber, as a reference commercial cork, and Kielmeyera coriacea and Plathymenia reticulata, which are native Cerrado cork species. The periderm of A. brasiliensis develops continuously around the stem with a thick cork layer. The cork has the typical characteristics of cork tissues with a compact structure of prismatic cells, stacked base to base in the radial direction without intercellular spaces. Cell walls were heavily corrugated and growth rings were present with a distinction of earlycork and latecork cells. A. brasiliensis cork cells are larger (49.1 µm prism height and 5.5 × 10^–5 cm² base area) than those from the reference Quercus suber cork, the number of cells per unit volume is smaller as well as the fraction of solid volume (7.6%), contributing to a lower density of cork. Chemically A. brasiliensis cork is characterized by a low suberin content of 5.6%, and a high lignin content of 45.5%, and includes 13.6% extractives. The ethanol–water extracts have low phenolic content and weak antioxidant activity. The cork of A. brasiliensis differs considerably from those of Q. suber, P. reticulata and K. coriacea, namely regarding its suberization level, which will impact the mechanical properties and limit the range of commercial applications, that should be directed towards insulation and low-density products.

Agonandra brasiliensis，象牙木，是一种来自巴西塞拉多的树种，树皮具有厚厚的软木层。本研究旨在描述这种软木塞的细胞特征和化学成分。研究了软木塞的细胞结构和生物特征，以及总结性化学成分。将结果与来自Quercus suber的软木塞（作为参考商业软木塞）以及Kielmeyera coriacea和Plathymenia reticulata（它们是本地塞拉多软木塞物种）的结果进行了比较。A. brasiliensis的周皮围绕茎不断发育，并带有厚厚的软木层。软木具有典型的软木组织特征，呈棱柱状细胞结构，呈放射状排列，无细胞间隙。细胞壁严重起皱，生长轮存在，早期软木细胞和晚期软木细胞有区别。A. brasiliensis软木细胞比参考Quercus suber cork更大（49.1 µm 棱柱高度和 5.5 × 10 ^–5 cm ²基面积），每单位体积的细胞数以及固体体积的分数（ 7.6%），有助于降低软木密度。化学A. brasiliensis软木的特点是木栓质含量低 5.6%，木质素含量高 45.5%，包括 13.6% 的提取物。乙醇-水提取物酚类含量低，抗氧化活性弱。A. brasiliensis的软木塞与Q. suber、P. reticulata和K. coriacea的软木塞有很大不同，即其软木化水平会影响机械性能并限制商业应用范围，应针对绝缘和低密度产品。