16 Order ALISMALES 
In shallow water in the western part of the state. Cherry county; 
Garden county; Mullen; Thedford; Wood Lake. 
3. Sagittaria longiloba Engelm. 
Near Minden; Mullen. 
4. Sagittaria rigida Pursh. 
In wet places and shallow water over most of the state. Ewing; 
Greenwood; Kennedy; Lincoln; Neligh. 
5. Sagittaria graminea Michx. 
In muddy places and shallow water mostly in the eastern part of the 
state. Halsey; Holt county; Lincoln; Mead; Minden. 
4. Alisma. 54. 
1. Alisma subcordata Raf. Water-plantain. 
Alisma plantago-aquatica L. 
Common in mud or shallow water over most of the state. Alliance; 
Anselmo; Callaway; Cherry county; Halsey; Homesville; Newark; 
Peru; Plainview; Valentine; Wood Lake. 
2. SCHEUCHZERIACEZ. 
1. Triglochin. 52. 
Carpels three, axis to which they are attached three-winged. 
1. T. palustris. 
Carpels six, axis hexagonal. 2. T. maritima. 
1. Triglechin palustris L. Arrow-grass 
Sand-bars of the Niobrara River. 
2. Triglochin maritima L. Arrow-grass. 
In marshy places in various places in the state. Poisonous to stock 
both in the green state and in hay. Alliance; Burwell; Newark; 
Thedford. 
3. POTAMOGETON ACE. 
Pondweed Family. 
Flowers perfect, usually on elongated peduncles. 
Perianth segments 4; fruiting peduncles straight. 1. Potamogeton. 
Perianth wanting; fruiting peduncles coiled. 2. Ruppia. 
Flowers monecious, flower clusters sessile or short-peduncled. 
3. Zannichellia. 
1. POTAMOGETON. 41. 
Pondweeds. 
With both floating and submerged leaves. 
Stipules axillary and free from the leaves. 
Submerged leaves bladeless, about 2 mm. wide. 1. P. natans. 
Submerged leaves with proper blades. 
Upper submerged leaves much broader and shorter than the 
lower. 2. P. amplifolius. 
Upper submerged leaves not very different from the lower. 
Floating leaves gradually narrowed into short petioles; foli- 
age and spikes reddish. 3. P. alpinus. 
Floating leaves abruptly narrowed into long petioles. 
