I have found this plant which has 1" to 2.5" leaves this time of year. It grows as emergent or submerged on the bottom detritis in ditches or fast flowing seasonal streams. It is easily disturbed in shallow water and floats to the surface with small roots. It appears to be whorled with the leaves coming out from the root or rhizome. Leaves may have a pointed or rounded tip. It has a central midline down each leaf. The very fine veins (best seen backlit from the back side of the leaf) start from the mid-rib and follow the edge of the leaf. The basal leaves die back. Most plants seem to be host to a brown scale-like oval egg mass that is flat on the plant side and peels off easily. Appears to send out runners to reproduce as they often grow in a line. Attached are several photos.