Soqotri

ṣ̌áˁarher - uneatable date; sterile palm (LS 157; CSOL I 662; CSOL II 595)

Likely a metathetic.

PWS
*ˁḳr - to be sterile, without offspring (of man and woman) (SED I No. 1ᵥ; HALOT 874)