Styrax japonicus, a new Record for Massachusetts

We report Styrax japonicus Siebold & Zucc. (Styracaceae) growing and reproducing spontaneously on Martha’s Vineyard in the town of Tisbury, a new record for Massachusetts (Angelo and Boufford 2019). This native of east Asia (Trueblood 2009), widely available in the horticultural trade, has previously been recorded growing in the wild in New England from a single location in Fairfield County, Connecticut (EDDMapS 2019). We found three mature plants of Styrax japonicus, the largest approximately 7 m tall with two trunks, each measuring 10 cm in diameter at breast height. The second mature tree was immediately adjacent to the largest tree, and the third was 3 m distant. Also present were three saplings ranging from 1 m to 2 m tall, the largest measuring 3 cm in diameter at its base. In addition, there were more than 350 seedlings, which were dense enough in some areas to form a groundcover (Figure 1). The trees, saplings, and seedlings occupied an area measuring approximately 10 m 3 10 m. We found the Styrax japonicus growing in mesic woods near the shore of a freshwater pond on conservation land. Accompanying plants included Acer rubrum L., Chimaphila maculata (L.) Pursh, Clethra alnifolia L., Cypripedium acaule Ait., Kalmia angustifolia L., Pinus rigida P. Mill., Pinus strobus L., Prunus serotina Ehrh., Quercus alba L., Quercus velutina Lam., Sassafras albidum (Nutt.) Nees, Toxicodendron radicans (L.) Kuntze, and Vaccinium corymbosum L. The mature trees were in fruit at the time of our discovery (Figure 2). We identified the species using Fritsch (2003): axillary fruits present, leaf blade margins serrate, and pedicels 15–50 mm in length. Given the reproductive success of our mature Styrax japonicus, we judge the plants to be well established at their Martha’s Vineyard location. Generally, the species has not been considered to pose an invasive threat (Gilman and Watson 2014; Trueblood 2009). To date, no official state list of invasive plants has included S. japonicus (Swearingen and Bargeron 2018). We did, however, find mention of