26 
Besides the localities of peculiar forms mentioned above, the 
range of the species is indicated by the following stations. Com- 
mon throughout Canada from the Atlantic to the Pacific and 
rom Maine and Vermont through New Jersey to North Carolina; 
Lake Huron (Macoun.); Sault Ste. Marie, Mich. (Morong); Chicago, 
Ш. (Babcock); Armstrong’s Grove, Iowa (Cratty); Sherburne Geyser 
Basin, National Park (Clifford Richardson); Falcon Valley, Wash- 
ington (Suksdorf); Salt Lake City, Utah (M. E. Jones); Ruby 
Lake, Nevada (Watson). Attributed by Brewer and Watson, 
Bot. Cal., to Soda Spring, near Mono Pass, Cal. (Plate XXXIV. 
submerged leaves on the left.) 
II. POTAMOGETON SPATHUL/EFORMIS (Robbins) Morong. 
P. gramineus, хат. (?)spathuleformis, Robbins in A. Gray, Man. Ed. 
5, p. 487 (1867). 
P. spatheformis, Tuck. in Herb. 
P. varians, Morong in Herb. 
Rootstock running, producing many branching stems 2—3 feet 
high. Floating leaves obovate, sometimes elliptical, abruptly 
acute at the apex and usually sloping at base, rather thin, 1 3-23 
nerved, 1-277 inches long and 6-13 lines wide, on slender petioles 
1-4 inches in length. Submerged leaves pellucid, spatulate-oblong 
or linear-lanceolate, 2-4 inches long and 3-9 lines wide, 5-13 
nerved, cuspidate or spinescent at the apex and sloping at base, 
all sessile at first, with age subsessile or even petioled. The sub- 
merged leaves are often reduced to phyllodia or forms with a very 
narrow blade and a long acumination at the apex and base. Ре- 
duncles often thickening upwards, 1-2 inches long. Stipules ob- 
tuse, faintly keeled, the apex slightly cucullate and splitting on 
pressure. Spikes large, densely flowered. Fruit like that of 
heterophyllus, about 1 line long by 34 line broad, roundish or 
obliquely obovate, obscurely 3-keeled, with a curved or slightly 
angled face; style apical or facial; embryo with the apex nearly 
touching the base and pointing slightly inside of it. 
This plant was discovered by Prof. E. Tuckerman as long ago 
as 1850 in Mystic Pond, Medford, Mass., and named Р. spatheformis 
in his herbarium. Dr. Robbins obtained it afterwards from the same 
locality in 1856 and 1867, and published it as above cited. The 
Present writer visited the spot several times in 1879-81 and found 
