144 MYRTALES 



1. Ammania cocci nea Rotth. 



Common in wet places in the southeastern part of the state. Ken- 

 nedy; Lincoln; Nebraska City; Weeping Water; Plainview. 



2. Ammannia auriculata Willd. 



Rare in the southeastern part of the state. Fillmore County; Lincoln. 



2. Didiplis. 648. 



1. Didiplis diandra (Nutt.) Wood. 



Rare in the southeastern part of the state. Lincoln. 



3. Rotala. 649. 



1. Rotala ramasior (L.) Koehne. 



In wet places, rare. Cherry County; Lincoln. 



4. Ly thrum. 649. 



1. Lythrum alatum Pursh. 



Common in wet ground, especially along ponds, streams, and ditches. 

 Callaway; Endicott; Laurel; Lincoln; Mead; Nebraska City; New 

 Helena; IPonca; Plummer Ford; Valentine. 



2. ONAGRACEAE. 



Calyx persistent; hypanthium not prolonged beyond the ovary. 

 Leaves opposite, stems procumbent or floating. 1. Isnardla. 



Leaves alternate, stems erect or ascending. 2. Ludwigia. 



Calyx deciduous; hypanthium usually prolonged beyond the ovary. 

 Seeds with a tuft of hairs, calyx tube, little if at all, prolonged be- 

 yond the ovary. 

 Flowers over 15 mm. broad, petals entire. 3. Chamaenerion. 



Flowers less than 15 mm. broad or the petals notched at the apex. 



4. Epilobium. 

 Seeds without a tuft of hairs, calyx tube distinctly prolonged beyond 

 the ovary. 

 Caulescent plants, flowers axillary or spicate. 



Ovules and seeds usually numerous, more than four; fruit a 

 dehiscent capsule. 

 Stigma four-toothed or four-lobed. 



Stigma deeply cleft into 4 linear lobes. 

 Capsule not broadly winged. 

 Flowers yellow, nocturnal. 



Ovules and seeds horizontal, angled; capsule tapering 



from a thickened base. 5. Onagra. 



Ovules and seeds ascending, not angled; capsule of 



nearly uniform diameter. 6. Oenothera, 



Flowers white or pink, mostly diurnal. 



Capsule not narrowed into a curved beak; leaves 



mostly over 25 mm. long. 



Ovules in one row in each cavity of the ovary, 



ascending. 7. Anogra. 



Ovules in many rows in each cavity of the ovary, 



on slender stalks. 8. Hartmannia. 



Capsule narrowed into a curved beak, leaves 8-15 mm. 



