Table 1.

Sodium concentration in roadside plants

Species	Sodium (ppm)		Nitrogen (%)
	Roadside (control)	F1,4	Roadside (control)	F1,4
Milkweed	2,065 (62)	11.1*	4.87 (4.75)	0.03
Mustard	115 (112)	0.07	3.73 (3.35)	1.65
Oak	50.9 (35.8)	33.9†	2.60 (2.37)	1.06
Grass	71.6 (54.7)	0.65	3.21 (2.97)	0.20

Shown are nutrient concentrations in plants collected along roadsides or from control sites over 100 m away. For sodium values, statistics were performed on log-transformed data (raw values are shown as means).

^*P < 0.05.

^†P < 0.01.