As evidenced by the photo at right, common false pimpernel is a low, branching annual with lax stems. The stems range from 5 to 20 cm in length. The leaves are all on the stems and are mostly entire to occasionally with small teeth. The leaves are up to 3 cm in length with the leaves narrowed gradually to the base.
The flowers are typically solitary within the leaf axils. The flowers are tubular with the 5 lobes at the mouth forming two lips. The corolla ranges from 7-10 mm in length. The flower stalks range from 5-15 mm long.
Lindernia dubia differs from its cousin, Lindernia anagallidea in having larger flowers but shorter flower stalks. In the former species, the pedicels are equal to or only slightly surpass the subtending leaves, while the latter species has all but the lowest flower pedicels noticably surpassing the subtending leaves. The former species usually has larger leaves, while the latter species has leaves from 6-15 mm long that are mostly broadly rounded at the base.
Common false pimpernel is common along the mudflats and bottomlands of the Columbia River and into the mouths of the larger rivers running into it.
Common false pimpernel is common in the easern and central United States. It is also found into South America. It is evidently rarer in the west, to which it may be an introduced species.