Sahih Al Bukhari Hadith Number 2433

Narrated Ibn ‘Abbas (ra): Allah’s Messenger (peace be upon him) also said, “It (i.e., Makkah’s) thorny bushes should not be uprooted and its game should not be chased, and picking up its fallen things is illegal except by him who makes public announcement about it, and its grass should not be cut.” ‘Abbas said, “O Allah’s Messenger ! Except Idhkhir (a kind of grass).” The Prophet (peace be upon him) said, “Except Idhkhir.”