1903] Robinson,— Generic Position of Echinodorus parvulus 89 
larger gland near the centre of each lateral face. Æ. parvulus is the 
only one of these species as yet found in the northeastern states and 
in this region seems to have been found only at the Winter Pond sta- 
tion in Winchester, Massachusetts, and many years ago in fresh water 
pools near Mt. Auburn, Massachusetts. The species has been found 
several times in the neighborhood of St. Louis, Missouri, and on the 
Illinois side of the Mississippi by Dr. Engelmann and by Mr. Henry 
Eggert, at Canterbury, Delaware by Mr. W. M. Canby, on the Santee 
Canal, South Carolina, by Mr. H. W. Ravenel, in Decatur County, 
Georgia, by Mr. R. M. Harper, and at Tampa and Dunnellon, Florida, 
by Mr. A. H. Curtiss. There are also indefinite reports of its occur- 
rence in Michigan and on the north shores of Lake Superior. ‘These 
last records need substantiation and, in general, the rarity of the species 
is such that the discovery and record of new stations will have more 
than ordinary interest. It is not improbable that the species from its 
small size, inconspicuous flowers, and habit, to which Mr. Rand has 
called attention, of growing in some cases entirely under water, has 
been overlooked in many localities where it really occurs. 
Plate 45, figure 1, representing the flower of Echinodorus parvulus 
shows the petals very short and distinctly obcordate, but it should be 
said that this was drawn from a young flower scarcely in anthesis, and 
that a more mature flower would probably exhibit relatively larger 
petals, which perhaps lose something of their obcordate form. ‘The 
petals are so thin and “deliquescent” that, it is by no means easy to 
trace their mature form in dissections made from dried material. 
EXPLANATION OF PLATE 45, FIGURES I TO 10. Fig. 1, Echinodorus parvulus, 
Engelm., young flower; fig. 2, the same, fruiting head ; fig. 3, the same, carpel ; 
fig. 4, the same, submersed state, showing phyllodial leaves; fig. 5, the same, 
emersed state, showing usualleaf-form. Fig. 6, reproduction of Seubert's prob- 
abiy incorrect figure of the flower of Alisma tenellum, Mart. Fig. 7, Echinodorus 
radicans, Engelm., carpel. Fig. 8, E. rostratus, Engelm., carpel. Fig. 9, Alisma 
Plantago, L., fruiting head, showing annular arrangement of carpels. Fig. 10, 
Echinodorus radicans, Engelm., fruiting head, showing capitate carpels. 
GRAY HERBARIUM. 
