696 



Lythraceae 



Rotala 



o So 



Map 1464 



Didiplis diandra (Nutt.) Wood 



Plants aquatic, collapsing when taken from the water; petals none; calyx tube 



without appendages; capsules indehiscent 5475. Didiplis, p. 697. 



Calyx tube cylindric, striate, generally 4-5 mm long in flower; petals 5 or more; 



plants commonly more than 6 dm high 5476. Lythrum, p. 697. 



Flowers large, in axillary cymes ; long, curving, semi-shrubby plants 



5488. Decodon, p. 698. 



Flowers irregular and unsymmetrical ; petals unequal; plants glandular-pubescent. 

 5478. Cuphea, p. 698. 



5473. ROTALA L. 



[Fernald & Griscom. The variations of Rotala ramosior. Rhodora 37 : 



168-169. 1 pi. 1935.] 



Plants low, simple or branched, rarely more than 3 dm high; leaves usually ascending, 

 the larger ones 1.5-4 (5) mm wide; capsules 2-3.3 mm wide, 2-4 mm long; bract- 

 lets subulate, 0.5-1.4 mm long 1. R. ramosior var. typica. 



Plants robust, up to 4.5 dm high, simple or branched; lower leaves usually widely 

 spreading or reflexed, the larger ones 5-10 mm wide; capsules (3.2) 3.8-4.4 mm 



wide, 3.5-5 mm long; bractlets linear-lanceolate, 1.6-2.4 (4) mm long 



la. JR. ramosior var. interior. 



1. Rotala ramosior (L.) Koehne var. typica Fern. & Grisc. Map 1461. 

 All the specimens I have seen are from the wet sandy areas of the north- 

 western part of the state. It is local and is found in ditches and on the 

 borders of sloughs. 



Coastal Plain from Mass. to Fla. and Tex.; sands of s. Mich., n. Ind., 

 111., and Minn. ; also in Wash, and Oreg. 



la. Rotala ramosior var. interior Fern. & Grisc. Map 1462. My speci- 

 mens are all from southern Indiana except a typical one from Steuben 

 County. Infrequent to local and found in mud in ditches, on borders of 

 sloughs, on muddy shores of streams and artificial ponds, and in wet 

 woods and fallow fields. 



N. Y. to Iowa, southw. to Fla., La., and Okla. 



