26 Rhodora [FEBRUARY 
In maturing the staminate flower is pushed up to the surface of 
the water on a long slender thread-like stalk, in the same manner 
as is the pistillate flower. They have sepals 5 mm. long, and anthers 
2.5-4 mm. long. This very distinct plant has recently been re- 
described as Elodea Iowensis Wylie (Philotria Iowensis Wylie),! as 
Philotria Iowensis Wylie (Elodea Iowensis Wylie),? and as Elodea 
ioensis Wylie.’ Wylie contrasts his species with E. Planchonii Cas- 
pary, laying emphasis on his new species having the staminate spathe 
“sessile, contracted at base" instead of as in Planchonii having the 
staminate "Spathe peduncled." This difference exists only in the 
terminology employed by Wylie and by Rydberg. E. Planchonii 
Caspary was described as having no petals in the staminate flowers. 
Wylie described and figures* E. ioensis Wylie as having, in the stam- 
inate flowers, linear lanceolate petals, 44 mm. wide. Examination 
of a staminate flower from the duplicate type of E. Planchonii showed 
no petals. None of the other material at hand, including Wylie's 
distribution of E. ioensis, showed any petals. It is probable that 
the petals in the staminate flowers are evanescent, and only to be 
seen when flowering material is kept under constant observation, 
as did Wylie with his plant at East Okoboji Lake, Iowa. Comparison 
of duplicate type material of Elodea Planchonii Caspary with authen- 
tic and beautifully prepared material of E. ioensis Wylie distributed 
by Wylie himself, proves the two to be identical. 
KEY To THE New ENGLAND SPECIES OF ELODEA. 
A. Staminate flowers wanting; leaves firm, oblong or ovate-oblong, usually 
obtuse, crowded and strongly imbricated at the summit of the stem. 
1. E. canadensis Michx. 
A’. Staminate flowers present; leaves linear, lance-linear, lanceolate, or lance- 
oblong, usually acute, the internodes marked, the leaves divergent, 
scarcely imbricated even at the summit of the stem. 
B. Staminate spathes sessile, the tips not widely divergent; peduncles 
of staminate flowers not exceeding the spathes, at anthesis breaking 
and setting free the flowers which float to the surface of the water, 
pues not exceeding 2.5 mm. in length, anthers less than 2.5 mm. 
ong. 
C. Staminate spathe globose apiculate, the body about 2 mm. long, 
anthers 0.8-1.1 mm. long; leaves linear, flaccid. 
2. E. occidentalis (Pursh) St. John. 
C”. Staminate spathe lanceolate-ovate, 5-6 mm. long, the anthers 2 mm. 
long; leaves lance-oblong, firm. 
3. E. Nuttallii (Planchon) St. John. 
! Proc. Iowa Acad. Sci. xvii. 82 (1910). 
? Science n. s. xxxiii. 263 (1911). 
3 Iowa State Univ. Nat. Hist. Bull. vi. 48 (1913). 
! Iowa State Univ. Nat. Hist. Bull. vi. pl. 2, f. 7 (1913). 
