Why Was a Poison Bean Used
to Decide Guilt?
A West African bean once decided a person's guilt by whether they survived drinking it. A Hokkaido cherry tree grows to 20 meters tall.
Sorted by what makes them memorable, twelve plants fall into three groups.
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Three Kinds of Plant Facts
Ayatoki's Plants puzzles range from Hokkaido rice varieties to a bean once used in African trial rituals, and every correct guess comes with a short trivia note. Sorting twelve of our favorites by what makes each one stick turns up three groups: plants that are genuinely dangerous, plants tied to Japanese culture and history, and plants that simply break a record.
Genuinely Dangerous
01
からばるまめkarabaru mame
The Calabar bean, a highly toxic legume native to West Africa. It was once used in a form of trial by ordeal: a suspect drank an extract of the crushed seeds, and surviving was taken as proof of innocence.
02
マンジョカmanjoka
Another name for cassava, the South American root crop that tapioca is made from. Some varieties produce hydrogen cyanide if eaten raw, so cassava must always be cooked or soaked in water before eating — the processed root is then ground into flour used in countless dishes.
03
ヤマウルシyama urushi
A deciduous shrub in the sumac family, turning a brilliant red in autumn. Its sap causes a severe skin rash on contact, and since it closely resembles the related nurude tree, hikers sometimes brush against it by mistake.
Rooted in Japanese Culture and History
04
ミヤギノハギMiyagino hagi
A bush clover counted among the "Seven Flowers of Autumn" in classical Japanese poetry, and the official prefectural flower of Miyagi. Its slender branches carry many small purple-red, butterfly-shaped flowers, a favorite subject in haiku and waka for centuries.
05
エゾスズシロezo suzushiro
A perennial in the mustard family native to Hokkaido, blooming with small white flowers in spring. Its name, suzushiro, is an old word for daikon radish — one of the "Seven Herbs of Spring."
06
水前寺菜suizenji-na
A leaf vegetable long cultivated around the Suizenji area of Kumamoto, known for its thick leaves and distinctive purple stems. Briefly blanched, it develops a slippery texture and is prized locally as a nutrient-rich vegetable.
07
ベンテンツゲbententsuge
An evergreen shrub cultivated as a garden and bonsai plant in Japan since the Edo period. It's remarkably tough and bounces back well after pruning, making it a popular "hard to kill" choice for beginner gardeners.
Record-Breaking or One-of-a-Kind
08
シウリザクラshiuri-zakura
A wild cherry species native to Hokkaido and the subalpine zones of Honshu, growing up to an impressive 20 meters tall — far larger than the familiar Somei-yoshino. Rather than the usual single blossoms, it produces clusters of small white flowers in brush-like spikes.
09
ななつぼしnanatsuboshi
A rice variety representing Hokkaido, prized for its chewy texture and balanced sweetness. It's so widely grown that it now accounts for roughly half of all rice produced in the prefecture.
10
コブシモドキkobushi modoki
An evergreen tree with white flowers resembling the kobushi magnolia, but classified as a separate, rare species found only on Amami Ōshima, Okinawa, and other islands in Japan's southwestern chain.
11
アオシマウリaoshima uri
A native Japanese melon variety with distinctive blue-green stripes on its skin. Its soft, juicy flesh has long made it a favorite for pickling, especially in shallow, quick pickles.
12
クレアローズCrea rose
An English rose known for its beautiful cup-shaped blooms — which gradually shift into a flatter, rosette shape as the flower matures. The same bloom can look like two entirely different varieties depending on when you catch it.
A New Plant, A New Fact, Every Day
Every one of these came from a single round of Ayatoki's Plants genre puzzle. Guess the hiragana word, and you'll get a short trivia note like the ones above.
💡 Most of the Plants genre's memorable facts fall into "record-breaking or one-of-a-kind" — genuinely dangerous plants are the rarest category, which is exactly why they stand out.