Department of Biology, College of Science, Princess Nora Bint Abdul Rahman University, Saudi Arabia
Key words: Autecology, Arta, Calligonum comosum, Saudi Arabia.
This study is to investigate the aspects of the autecology of Calligonum comosum plant. This plant species is one of the famous pastoral plant characterizing the habitat of Saudi Arabia. The C. comosum plant is belonging to the botanical family polygonaceae, plant is frequently used as sources of medicine by rural people. The study site was located in the north-east of Riyadh city, in “Dahna” area. The results showed that C. comosum is dominant plant in the area, 23 plant species were recorded in the study site, belonging to 16 families, they contain 11 perennial types and 12 annuals types, and the C. comosum is important companion plant. C. comosum is perennial shrubs, branched from the base to height of 100 to 200 cm. The fruits are spherical shape with a thick and long hair its color from yellow to red, this plant is characterized by pure pungent smell and excessive rigidity because it is config.d solid wood. The life cycle of C. comosum is regular for perennial plants, started grow from the seeds after the seasonal rains during November, the flowers and composition of fruits started at March, the production cycle of this plant is about 4 months. The electrical conductivity (EC) of the soil was ranged from 6.4 to 6.7 dS m-1 and, the concentration of SO4 and Fe relatively high. The plant accumulates high content of Mg, Si, Cl and K in their tissues.