Steele Additions to the Flora of Washington. 49 



Isoetes saccharata Palmeri A. A. Eaton, var. nov. 



Aspect of riparia. Leaves much stouter than in the type, 1 to 1| dm. 

 long, recurved; macrospores 500 to 550 M, with markings taller and more 

 confluent, strongly suggesting riparia. 



This variety might easily pass for riparia, which has, indeed, hap 

 pened several times; but the very narrow, almost obsolescent velum, the 

 less tuberculate microspores, the smaller, more closely sculptured macro- 

 spores, and the dirty brownish color when dry, sufficiently distinguish 

 it. The spores appear intermediate between riparia and the varieties of 

 eckinospora in sculpture, some of the markings being irregular walls, 

 others broad, often forked spinules as in Braunii. 



First collected by Mr. T. C. Palmer, of Media, Pa., at Lloyd's Creek, 

 Sassafras River, Maryland, August 12, 1895, and by him ably charac 

 terized*'. Specimens collected by Mr. Frederick V. Coville at the foot 

 of the Washington estate, Mount Vernon, Va., do not fully agree, but 

 apparently connect the variety with the typical form of the species. 



Types in the herbarium of A. A. Eaton, the National Herbarium, and 

 those of the Missouri Botanical Garden, the University of Minnesota, 

 and the Linnaean Fern Chapter. A. A. Eaton. 

 I253&. Tsoetes saccharata reticulata A. A. Eaton, var. nov. 



Smaller; leaves 10 to 20, slender, erect, vivid green, 1.5 to 2 dm. long, 

 with abundant stomata; macrospores 400 to 432 J/, marked with low, 

 parallel, anastomosing walls above and more or less regularly reticulate 

 below. 



The aspect of this plant also suggests riparia rather than saccharata. 

 The spores sometimes resemble those of small Tuckermani or even En- 

 gelmanni, but the walls are much lower, often mere threads. Occasion 

 ally a spore is found which bears parallel walls below as well as above. 



Hunting Creek by the wagon bridge near its mouth, one mile below 

 Alexandria, Va., July 22, 1888, Geo. Yasey and Frederick V. Coville; 

 same station, September 22, 1900, Wm. R. Maxon, No. 365. Also tide 

 beach, Anacostia river, Washington, D. C., September 1, 1900, E. S. 

 Steele. Perhaps referred to by Palmer (1. c. p. 222). Type specimens 

 are deposited in the herbaria mentioned in the description of the pre 

 ceding variety. f A. A. Eaton. 



886. Potamogeton Nuttallii Cham. & Schlecht. (P. Claytonii of 

 Ward's Catalogue.) 



Common in the tributaries of the Eastern Branch. 

 *88sa. Potamogeton amplifolius Tuckerm. 



Mouth of Four Mile Run and Hunting Creek, also in Anacostia river, 

 but flowers and fruit not seen. 

 *893a. Echinodorus radicans (Xutt.) Engelm. 



Along a depression in the flats below Chain Bridge, perhaps a dozen 



*Bot. Gaz. 4: 221. 1896. 



{The Vasey and Coville specimen cited above is that determined by 

 Theo. Holm in the third list of additions as /. riparia Engelm. It is 

 hence given the same number, and the asterisk is omitted. E. S. S, 



