Yasuyoshi Shirasawa

Who They Were

Yasuyoshi Shirasawa (白沢保美) was a Japanese botanist, forestry scientist and politician who lived from 1868 to 1947. He worked at the University of Tokyo alongside Tomitaro Makino, the man remembered as the father of Japanese botany, and he is credited with naming a number of native Japanese plants. Among the species he described is Picea koyamae, a spruce that is today listed as endangered. He also shares credit with Makino for naming Tilia kiusiana, the Kyūshū lime.

His working life spanned two worlds that rarely overlap so neatly. He was a field scientist who classified trees and shrubs, and he was also a member of the House of Peers, the upper chamber of Japan's imperial parliament. That combination — botanist, forestry official, peer — places him squarely in the Meiji and early Shōwa establishment, when the Japanese state was actively cataloguing and managing its natural resources.

Life and Career

Shirasawa was born in 1868, the year the Meiji era began. That same year the Tokugawa shogunate fell and political power was formally restored to the emperor, launching the period of rapid modernisation known as the Meiji period (1868 – 1912). His birth therefore coincided with the opening of the era whose institutions he would later serve.

He built his scientific reputation at the University of Tokyo, where he worked with Tomitaro Makino. Makino is the towering figure of Japanese plant taxonomy, and Shirasawa's association with him was both a collaboration and a training ground. Together they described Tilia kiusiana, the Kyūshū lime, a tree native to southern Japan. Shirasawa's own independent work included the naming of Picea koyamae, a spruce species that survives today under threat of extinction.

His career was not confined to herbaria and lecture halls. He held the position of member of the House of Peers, the appointed and hereditary upper house of the Imperial Diet. He was also active as a forestry scientist, a discipline of obvious importance to a country that depended heavily on its timber resources and was reorganising its forests under state management. He died on December 20, 1947.

Why They Matter

Shirasawa belongs to the generation of Japanese scientists who gave the country's flora its modern scientific names. Before this work, Japanese plants were known by a patchwork of local and classical names; after it, they had Latin binomials that could be placed on the international map of botany. Shirasawa contributed to that project directly, describing species that botanists still use and study.

His two best-known plants tell the story well. Picea koyamae, the Koyama spruce, is a rare conifer of central Honshu, and its endangered status makes Shirasawa's description of it a permanent reference point for conservation. Tilia kiusiana, the Kyūshū lime, extends his reach into the forests of the southern island. Both names carry the authority of the scientist who first set them down.

His political role matters for a different reason. Sitting in the House of Peers meant that a working botanist and forestry specialist had a seat in the legislature of an industrialising empire. That fact says something about how seriously Meiji and later Japan treated forestry and the scientific survey of its territory, and about the routes by which scientists of the period entered public life.

The Name in Japanese

The full name is written 白沢保美. It is read しらさわ やすよし in kana, and rendered in romaji as Shirasawa Yasuyoshi. The family name comes first, as is standard in Japanese. He is also encountered in English-language sources as Homi Shirasawa, an alternative reading of the given name.

Breaking the name down character by character:

白 — read しら (shira) in this name. It means "white." It is one of the most basic kanji in the language, a single stroke short of the character for "hundred."

沢 — read さわ (sawa) in this name. It means "marsh," "swamp" or "mountain stream." Together, 白沢 (Shirasawa) is a surname found across Japan, and it can also be read Shirasawa or Sawashiro depending on the family.

保 — read やす (yasu) in this name. It means "to protect," "to preserve" or "to keep." This is the same 保 that appears in words connected with conservation and maintenance.

美 — read よし (yoshi) in this name. It means "beauty" or "beautiful." This kanji is extremely common in given names, where it usually carries the reading み (mi), as in names like Yumi or Harumi. Here it takes the reading よし, which is a standard alternative in masculine names.

So the name as a whole can be glossed as "white marsh, preserved beauty" — a reading that is suggestive rather than literal, since Japanese names are chosen for sound and convention as much as for meaning. For a learner, the useful takeaways are the surname pattern 白沢 and the given-name pattern 保美, both of which recur in Japanese personal names.

Legacy

Shirasawa's legacy rests on the plants that carry his name in their scientific descriptions and on the institutional positions he occupied. Picea koyamae and Tilia kiusiana remain the clearest evidence of his taxonomic work, and the first of these has become a species of conservation concern, which keeps his name in circulation among botanists and foresters.

His membership in the House of Peers records a career that moved between science and the state at a time when Japan was assembling both a modern research university system and a modern legislature. He died on December 20, 1947, in the early years of the post-war settlement, having lived through the entire span of the Meiji era and well beyond it.