Pigweed
Portulaca oleracea
Portulacaceae
Reported to be edible. Medicianl uses also reported
Pigweed is is prostrate spreading annual or sometimes perennial plant. The stems can reach 25 cm long, leaves are small and fleshy or succulent (up to 25 mm long) and flowers are yellow in colour. Pigweed is fast-growing and can form a mat covering up to 90 cm. Pigweed is reported to be self fertile, but pollinators are known to visit flowers. The seed is small, brown to black and forms in small pods. Pigweed grows in a broad range of soils. It has a taproot and a fibrous secondary root system. It will thrive when adequate moisture is available, but can tolerate prolonged low soil moisture conditions. During these periods, plants are reported to switch photosynthetic pathways and use the Crassulacean acid metabolism (C4) pathway. This enables plants to conserve moisture by closing stomates during the day and opening them at night to capture carbon dioxide. See the Wisconsin Horticulture link for an excellent article on pigweed and its various attributes. The UNE link below also provides detailed information on pigweed.
A range of insects are known to visit flowers for pollen and nectar. One source shows Australian stinless bees visiting the flower of a Portulaca sp. Pigweed is known to have allelopathic effects - reduced growth of other plants (Rashidi). Pigweed is also reported to host various crop-damaging organisms. Insect problems include aphids, gnats, snails and slugs. Varieties of sawfly mine the interior of the leaves or feed on the leaves. A Cabi datasheet (see link below) provides a substantial list of organisms associated with this plant. A few of these are listed here: - Aspidiella hartii (yam scale) - Hercinothrips femoralis (banded greenhouse thrips,) - Hypogeococcus pungens (cactus mealybug), - Scirtothrips dorsalis (chilli thrips),- Cucumber green mottle mosaic virus - Reniform nematode, - Spodoptera eridania (southern armyworm) - Spodoptera frugiperda (fall armyworm), - Tomato spotted wilt orthotospovirus (tomato spotted wilt), - Tomato yellow ring orthotospovirus (Tomato yellow ring virus), - Turnip mosaic virus (cabbage A virus mosaic) - Aphis craccivora (groundnut aphid), - Aphis gossypii (cotton aphid), - Bemisia tabaci (tobacco whitefly), - Bemisia tabaci (silverleaf whitefly), - Frankliniella occidentalis (western flower thrips)