(1) Julia F Morton J, Fruits of Warm Climates. published by herself (1987), at 411-416 www.hort.purdue.edu/newcrop/morton/japanese_persimmon.html
(Japanese persimmon Diospyros kaki L[:] * * * Generally, the flesh is bitter and astringent until fully ripe, when it becomes soft, sweet and pleasant, but dark-fleshed types may be non-astringent, crisp, sweet and edible even before full ripening. * * * native to Japan, China, Burma and the Himalayas and Khasi Hills of northern India. * * * It has been recently discovered that there are two different mechanisms affecting astringency; one is degree of pollination, the other is the amount of ethanol produced in the seeds and accumulated in the flesh”)
(a) In other words, the classifications of persimmon in Taiwan (甜柿/澀柿; 軟柿/硬柿) are artificial, all belonging to the same species: Diospyros kaki L.
(b) Diospyros
en.wikipedia.org/wiki/Diospyros
(section 1 Taxonomy and etymology)
(c) Diospyros kaki. Delaware State University, undated
herbarium.desu.edu/arboretum/scientific_names/Diospyros_kaki/index.html
("etymology: Diospyros from Greek dios = divine, and pyros = wheat")
(2) persimmon
en.wikipedia.org/wiki/Persimmon
Quote: “The Japanese 'Hachiya' is a widely grown astringent cultivar. Some cultivars, such as Fuyū 富有, do not contain tannins when firm. They can be eaten like an apple or can be allowed to go to any stage of ripeness, including to the jelly-like stage. These non-astringent varieties are considered to have a less complex flavor.
(a) 蜂屋柿 [pronounced hachiya-gaki]. Kotobank, 小学館 (publisher), undated
kotobank.jp/word/%E8%9C%82%E5%B1%8B%E6%9F%BF
(b) The switch from “k” to “g” for “kaki” is because the “k” is no longer in the first syllable, to soften the pronunciation.
(c) koto 言 【げん(P); こと】 (n): “word; remark; statement” (The “gen” and “koto” are Chinese and Japanese pronunciations, respectively.)
(d) astringent (渋 in Japan; 澀 in Taiwan; due to presence of tannin)
(e) Search images.google.com with 蜂屋柿, and you will see its shape.
(f) “干し柿にする.” translation: made into dried persimmon (蜂屋柿 is often individually hanged to dry outdoors.)
(g) dried persimmon = 柿餅 (in Taiwan)