Suginami’s Natural Sciences: The Sudajii Plant

The Sudajii plant, belonging to the Fagaceae family and Fagaceae genus, is a fascinating specimen in the world of plants. Scientifically known as Castanopsis sieboldii (Makino) Hatus. ex T. Yamaz. and Mashiba, this plant has intrigued botanists and researchers for its unique characteristics and rich history.

The name “Sudajii” refers to this particular species of plant within the Fagaceae family. The Fagaceae family is known for its diverse array of trees and shrubs, including oak, chestnut, and beech species. The Sudajii plant, specifically Castanopsis sieboldii, is indigenous to Japan and is commonly found in the Suginami area.

The genus name, Fagaceae, has its origins in the ancient Latin name “Castanea,” which means chestnut, and “opsis,” which means similar. Despite having a masculine noun ending (-us), the genus name is treated as a feminine noun. This is an interesting linguistic aspect to consider when studying the Sudajii plant.

The species name, sieboldii, is derived from the name of a botanist named Siebold. It is not uncommon for plant species to be named after individuals who have made significant contributions to the field of botany. In this case, Siebold’s name is forever associated with the Sudajii plant.

The initial discovery and documentation of the Sudajii plant were attributed to Tomitaro Makino, a renowned botanist. However, the official presentation of the species was carried out by Kei Yamazaki and Shigehiko Mashiba, both of whom were prominent members of the Ecological Society of Japan and the Oita Biological Discussion Group. Later, Sumihiko Hatsushima, a professor at Kagoshima University, revised and refined the information about the Sudajii plant.

The Japanese name “Sudajii” is believed to be a corruption of the phonetic reading of “Shii,” which refers to acorns. This name is associated with the plant’s characteristic acorns, which are an essential part of its reproductive cycle.

In terms of distribution, the Sudajii plant is primarily found in Honshu, specifically towards the west of Fukushima and Niigata. It is also found in Okinawa and, interestingly, even on Jeju Island overseas. The Sudajii plant is typically found in coastal regions, while a related species, Tsuburajii, is more commonly found inland.

One notable characteristic of the Sudajii plant is its tree shape and winter bud. The leaves of the Sudajii plant are thick and have a well-developed cuticle, giving them a glossy appearance that reflects strong sunlight. This plant is an evergreen tree, meaning it retains its leaves throughout the year, adding a touch of greenery to any landscape.

The leaves of the Sudajii plant are mutualistic, which means they have a broad oval shape with a tip resembling a tail. The edges of the leaves are either entire or wavy serrations, usually found on the upper half. The leaves are thick and leathery, with a glossy dark green surface. The underside of the leaves is covered in dense gray-brown fine hairs, adding to the plant’s unique characteristics.

In terms of flowering, the Sudajii plant is monoecious, meaning it has both male and female flowers on the same plant. The flowers appear in late spring or early summer, typically in June. The plant produces panicle inflorescences, which are clusters of small flowers. The Sudajii plant relies on insects for pollination and has a strong fishy smell during the flowering period to attract them.

The Sudajii plant is a fascinating specimen that has captured the attention of botanists and plant enthusiasts alike. Its unique characteristics, distribution, and history make it an essential plant to study in Suginami’s natural sciences. Whether it is the glossy leaves, the distinct acorns, or the fishy-smelling flowers, the Sudajii plant continues to intrigue and inspire those who come across it in their botanical explorations.