Photo: Ohio State Weed Lab Archive, The Ohio State University, Bugwood.org common purslane Portulaca oleracea
This plant reproduces primarily from seed. Seeds germinate during the growing season from May through August. However, it can reproduce from broken stems. It generates roots at the nodes. Young leaves are opposite and smooth; green on top and reddish on the lower side. The leaves taper near the base where they attach to the stem. A mature plant has red to green succulent stems. The leaves still have opposite growth, but now are succulent.
Purslane produces small yellow flowers in late summer. The seeds that are produced in the fruit are black, flat and kidney shaped. The prostrate nature of purslane is similar to knotweed and spotted spurge, but there are distinct differences. Spurge produces a milky sap when a stem or leaf is broken. Knotweed has a papery sheath at the base of the foliage. Neither spurge nor knotweed is succulent like purslane.
Purslane can be found in landscape beds, newly seeded or thin turf areas, or cracks in pavement. It has a taproot so hand removal does require some digging. The proper use of mulch in ornamental plant areas can also effectively reduce this weed.
There are a number of pre-emergent and post-emergent herbicides labeled for purslane. Pre-emergents include, but are not limited to: flumioxazin (SureGuard), napropamide (Devrinol), oxadiazon (Ronstar), oxyfluorfen (Goal 2XL - nursery only), oxyfluorfen+pendimethalin (OH2 - nursery only), prodiamine (Barricade) and trifluralin (Treflan).
Post-emergents include, but are not limited to: bentazon (Basagran T&O), diquat dibromide (Reward - non-selective), flumioxazin (SureGuard), glufosinate-ammonium (Finale - non-selective), glyphosate (Roundup - non-selective) and oxyfluorfen (Goal 2XL - nursery only).
Remember to always read the label for proper application sites and rates.