Manusmriti
तमसा बहुरूपेण वेष्टिताः कर्महेतुना । अन्तस्सञ्ज्ञा भवन्त्येते सुखदुःखसमन्विताः ॥ ४९ ॥
These (plants) which are surrounded by multiform Darkness, the result of their acts (in former existences), possess internal consciousness and experience pleasure and pain.
english translation
tamasA bahurUpeNa veSTitAH karmahetunA । antassaJjJA bhavantyete sukhaduHkhasamanvitAH ॥ 49 ॥
hk transliteration by Sanscript