I12 | Muhlenbergia, Volume 3 
_» § Var. cuneata (Sheldon) Lunell. .S. cuneata Sheldon, 
Bull. Torr. Bot. Club, 20: 283. A/. 759. 1893; J. G. Smith, in 
Rep. Mo. Bot. Gard. 6: 8. Al. 2, 1894. Britton and Brown, II. 
Fl. 1: 89. 1896; Buchenau, |. c.—Plant submersed, rooting in — 
mud, maybe sometimes in sand too, slim and slender. Scare 
20-100 cm. long, with the verticillate flowers reaching the sur- 
face of the water. Leaves with long petioles, their blades float- 
ing on the surface, sagittate, very much smaller in size than in 
the preceeding varieties. Bracts ovate-lanceolate, usually shorter 
than the fertile pedicels. Achenes about 1mm. long. ‘This 
variety has phyllodes, some linear, attenuate, nearly reaching 
the surface of the water, others lanceolate, 6-12 cm. long, 4-8mm. 
broad, rosulately arranged around the base of the scape. 
Conditions favorable to the growth of long phyllodia are: 
1, sufficiently deep water; 2, when the power for a continued 
growth in developing a lamina is exhausted; and 3, when the 
phyllode is too young for the formation of a leaf blade, in which 
case a blade will come later, if the season is not too far advanced. 
The petioles of the floating leaves are very fragile indeed, and 
many of these leaves who simply lost their laminae by accident, 
pass as long phyllodes. 
| Besides this plant, the long phyllodes are found in the 
European Sagzttaria sagittacfolia vallisneriacfolia and in Alzs- 
ma arcuatum angustissimum, and the basilar phyllodes are con- 
stant in Sagzttaria cristata Engelm., S. Zeres Wats., S. gramz- 
nea Michx., and \S. swdulata (L,.) Buchenau. 
I have collected var. cuneata in places where many thou- 
sands of individual plants were growing, and nothing but this 
typical variety could be found. ‘The year was a wet year. The 
next year happened to be a dry year, all the water disappeared 
from the surface of the ground, and the plants were transformed 
into terrestrial plants. Ncta single var. cuzeata was found, but 
in their place just as many typical var. monomorpha! ‘This ob- 
servation has been repeated—and the reverse of it—in different 
places and through whole seasons, and furnishes a most con- 
