Like many Chinese genera of plants, Amsonia also occurs in eastern North America. Atypically, however, the centre for diversity for Amsonia is in eastern North America rather than Asia (compare with Magnolia or Acer Section Macrantha (the snakebark maples)). Of the twenty or so species of Amsonia, 16 occur in eastern North America, while only 4 are distributed in Asia. Amsonia elliptica is the only member of the genus that occurs in China.
The Flora of China summary for Amsonia elliptica reports that a “decoction of all parts is used to cure chills and to induce sweat.”
Not up to date my comment 2 years after but still want to add to the Amsonia elliptica entry that according to my files this species name refers to the Japanese representative whereas the Chinese call their species A. sinensis. In the Iconographia sinicorum 1974/3 plate 4812 it is described as annual and its habitat : Jiangsu and Anhui provinces are almost subtropical whereas the Japanese elliptica is described as perennial and native of Northern Hokkaido. Other morphological details i have not yet compared but can do on request.
Interesting, Herrmann. As you'll note, we've followed the Flora of China which presumably has meant the Apocynaceae expert has recently looked at this (in fact, he/she declares Amsonia sinensis to be a synonym of Amsonia elliptica).
Thanks for Your answer and explanatory remarks about the synonymy of Amsonia elliptica and A sinensis. Still i want to draw attention to the differences (based on the description of Iconographia Cormophytorum Sinicorum 1974/3 in comparison to that given for A. elliptica in the new Japanese Flora 1993/3a: Habit: size -30 cm, Leaves: 2,2-4,8 x 0.5-0.8 Corolla: 10mm (June) whereas the Japanese A. elliptica is given with 40-100 cm, leaves: 3-8 x 1-2,5 cm and corolla 17mm ´May-June. Sounds much like a varietal form.
Kind regards!