Most likely in the mid to low 30s but specific data lacking.
From the Greek “physa”, a bladder, and “stege”, a covering.
The somewhat popular common name “Obedient Plant” arises because the flowers remain put if re-positioned.
Because of its spreading habit, can become a weed in garden settings.
Recent Research Findings:
Kelly and Starman (1990) showed that after one week of dry storage at 32F, flower vaselife was 8 days, down from 14 days with no storage. These findings assume that the flowers were STS treated and flower food is used.