Definition
Parasitic seed plants derive nutrition by infecting host plants; they also can cuase disease in plants.
See: mistletoe, Cassytha filiformis , and dodder.
Discussion
Important disease-inducing genera of parasitic seed plants and their hosts.
| Genus of Parasitic Seed Plant | Example of Host Plant Attacked |
| I. ROOT PARASITES | |
| A. Broomrapes (Orobanchacea) | |
| 1. Aeginetia | maize, rice, sugarcane |
| 2. Christisonia | Sugarcane |
| 3. Orobanche | legumes, tobacco, tomato, cabbage, flax, hemp, grapes, watermelon, cucurbits, mint, sunflower, clover, eggplant |
| B. Figworts (Scrophulariaceae) | |
| 1. Alectra (Melamsa) | cowpeas, soybeans, peanuts, legumes, sugarcane |
| 2. Rhamphicarpa | maize, cowpeas, rice, sorghum |
| 3. Striga (witchweed) | maize, sorghum, sugarcane, tobacco, grasses |
| II. STEM OR LEAF PARASITES | |
| A. Cuscutaceae | |
| 1. Cuscuta | alfalfa, clover, sunflower, potato, sugar beets, tobacco, bamboo, asters |
| B. Lauraceae | |
| 1. Cassythia | evergreen shrubs and ornamentals, orange trees |
| C. Viscaceae | |
| 1. Arceuthobium | Conifers |
| 2. Dendrophthora | rubber, mango, avocado, cacao |
| 3. Korthalsella | acacia, eucalyptus |
| 4. Notothixos | eucalyptus |
| 5. Phoradendron | coffee, avocado, teak, various forest trees |
| 6. Viscum | rubber, conifers, fruit trees, deciduous trees |
| D. Loranthaceae | |
| 1. Amyema | eucalyptus |
| 2. Elytranthe | rubber, cashew |
| 3. Phthirusa | rubber |
| 4. Psittacanthus | citrus trees |
Source: Donald M. Knutson (1979). How Parasitic Seed Plants Induce Disease in Other Plants. pp. 293-309 In: Plant Disease, an Advanced Treatise (Vol. IV, How Pathogens Induce Disease). (Horsfall and Cowling, eds.) Academic Press, NY