Part of the valley bed of Wied Żembaq lodges a very old copse of the Wild Pear tree (Lanġas Selvaġġ), a very rare species with a restricted distribution in the Maltese Islands and the Mediterranean. This population was already recorded in the 19th Century and includes various old trees. Other accompanying tree species include numerous large Carob trees (Ħarruba). 

The area has been protected since 2001 as a Nature Reserve.

MEPA declared this site as a Tree Protected Area on the 24th May 2011, in accordance with the provisions of the Trees and Woodlands Protection Regulations (2011) as per Government Notice number 473/11.