Specimens of Ruppia from all eleven Nebraska counties in which it is known fall into two groups: R. occidentalis in alkaline Sandhills waters and R. maritima in saline waters of the Platte River Valley and Lancaster County. Ruppia occidentalis is distinguished by its more robust size; redspotted leaves and stems; terete, entire, obtuse leaves; 4-8(9) carpels; and by two elliptic white spots on ...
