Survey of host plants of Cassytha filiformis l. (Lauraceae) in selected coastal sites in Luzon

Cassytha filiformis is a twining and scrambling parasitic plant known to spread very fast along coastal areas. A survey to determine the host plants of C. filiformis and their morpho-anatomical defenses was carried out in selected coastal areas in Luzon. Quadrats (3 x 3 m) were laid within the perimeter of C. filiformis growing in the coastal thickets in Morong-Bataan, Baler-Aurora and Alaminos-Pangasinan to identify the host plants of C. filiformis and the frequency of their parasitization. A total of 67 plant species belonging to 65 genera and 30 families were found parasitized by C. filiformis. These were mostly herbaceous plants (60%) under the families Fabaceae, Poaceae, and Lamiaceae to name a few. The abundance and frequency showed that the Lantana camara is the species most frequently parasitized meanwhile, the family Fabaceae recorded the most parasit izations for an individual family having 9 of its genera parasitized. Morphoanatomical examinations revealed that the host plants exhibit high trichome density by as much as 100 units/mm2, the trichomes being mostly of glandular type. The haustoria of C. filiformis, were found to penetrate up to the xylem tissue of the herbaceous stems. In the woody stems, the haustoria were found to attach to the host plants’ epidermis only. The study confirms the non-discriminatory nature of C. filiformis as a parasitic plant. Herbaceous habits and presence of trichomes serve as poor defense systems against C.filiformis