1910] Flora of the Boston District,— VI. 3 
obtusata Rehder, Möller’s Deutsch. Gurtn.-Zeit. XVIII. 577. 1903. 
Leaves oval to oblong-obovate, rounded at both ends or only slightly 
narrowed, at the apex furnished with an obtuse yellowish mucro, 
4-7 cm. long and 2.3-3.7 cm. broad, dark green above and on both 
sides with a conspicuous yellow midrib; petioles stout scarcely 1 cm. 
long. Like the preceding form this is of slow growth and forms a 
compact bush, the broad obtuse stiff leaves resembling those of Rhodo- 
dendron catawbiense except that they are smaller. This form is in 
cultivation at the Arnold Arboretum since 1886, when it was propa- 
gated from a plant discovered a short time ago by Mr. James Bowditch 
near Pomfret, Connecticut. 
ARNOLD ARBORETUM, 
REPORTS ON 'THE FLORA OF THE BOSTON 
DISTRICT,— VI. 
ALIS MACEAE. 
ALISMA. 
A. Plantago-aquatica L. Shallow water with muddy bottom, 
throughout. 
ECHINODORUS. 
E. tenellus (Martius) Buchenau. “Near Mt. Auburn, Cambridge" 
(Thomas P. James, 1868 and August, 1869); “On margin of pond, 
north side Watertown road above R. R. station at Mt. Auburn, Cam- 
bridge” (Wm. Boott, Aug. 31, 1869); “Mud Pond, Watertown Road" 
(Thomas P. James, September, 1873). Muddy shore of Winter Pond, 
Winchester, various collections since 1876. These are the only New 
England stations ever reported for this very rare plant. 
LOPHOTOCARPUS. 
L. spongiosus (Engelm.) J. G. Sm. Alewife Brook, W. Cambridge 
(Wm. Boott, Aug. 21, 1870); Mystic River (Wm. Boott, September, 
1863 and Aug. 12, 1868); bank of Mystic Pond (Wm. Boott, Oct. 1, 
1876); Woburn Pond (Wm. Boott, Aug. 21, 1863); tidal river flats, 
Newburyport (4. A. Eaton, 1898; M. L. Fernald, Oct. 2, 1902). 
