Conophytum

Japanese: Conophytum

... Bergeranthus is a small, colonial plant with thin leaves, and is exceptionally cold-tolerant among mesembs. (4) Perennial, stemless, with a few highly fleshy leaves. This group is called Tamagatamesen, and includes Lithops , Conophytum, Fenestraria ( two species, the representative of which is Isuzudama (Isuzutama) F. aurantiaca NEBr.) (illustration), Opthalmophyllum (18 species), Argyroderma (about 50 species), Pleiospilos (33 species), and Gibbaeum (about 20 species). Highly succulent species dislike high temperatures and humidity, so they should be grown in a well-ventilated shade in summer with limited water or forced to be deprived of water.

From [Lithops]

…The Lithops genus was first discovered in 1811 by the Englishman Burchell. A large group close to the Lithops genus is the Conophytum genus. It is distinguished from Lithops by the presence of bracts on the flower stalk. …

*Some of the terminology that mentions "Conophytum" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…ベルゲラントゥス属Bergeranthusは小型で，群生し葉は細く，メセン類では例外的に耐寒性が強い。(4)多年生で無茎，少数の葉が高度に多肉化した群　玉型女仙（たまがためせん）と呼ばれるグループで，リトープス属Lithops，コノフィトゥム属Conophytumのほか，葉の上部が半透明の凸レンズ状になったフェネストラリア属Fenestraria(2種あり，代表種はイスズダマ(五十鈴玉)F.aurantiaca N.E.Br.)（イラスト），オプタルモフィルム属Opthalmophyllum(18種)，アルギロデルマ属Argyroderma(約50種)，プレイオスピロス属Pleiospilos(33種)やギッバエウム属Gibbaeum(約20種)などの諸属が見られる。　高度に多肉化した種群は高温多湿を嫌うので，夏期には通風のよい日陰で，水を控えて育てるか，強制的に断水する。…