108 Rhodora [JUNE 
HYBRIDS. 
S. ALBA L. X FRAGILIS L. A large staminate tree, persisting since 
before 1859, Cambridge (W. Deane); pistillate tree, Cambridge (L. H. 
Bailey, May, 1883); a large staminate tree, Dorchester (J. R. 
Churchill, 1887-8). 
S. CINEREA L. X cordata Muhl. Waste ground, Back Bay, 
Boston (F. F. Forbes, 1907). 
S. cordata Muhl. X lucida Muhl. Knoll by Brookline water- 
works land, Dedham (F. F. Forbes, 1908). 
S. cordata Muhl. X pedicellaris Pursh., var. hypoglauca 
Fernald. Wet soil; Concord, Wayland, W. Roxbury, Dedham. 
S. cordata Muhl. X petiolaris Sm. Swamps; North Andover, 
Cambridge, Boston, Brookline, W. Roxbury, Dedham, W. Quincy, 
Sherborn. : 
S. cordata Muhl. X rostrata Richards. Reservoir lot, Brookline 
(F. F. Forbes, 1909); border of swamp, Charles River meadow, 
Dedham (F. F. Forbes, 1908). 
S. cordata Muhl. X sericea Marsh. Cambridge, W. Roxbury, 
Milton, W. Quincy, Sharon, Sherborn. 
S. cordata Muhl. X subsericea (Anders.) Schneider. Cam- 
bridge (L. H. Bailey, 1884); border of swamp, Cow Island, W. 
Roxbury (F. F. Forbes, 1907 et seq.). 
S. discolor Muhl. X humilis Marsh. Brookline, W. Roxbury, 
Wellesley, Natick; Middlesex Fells, according to Deane, Fl. Metrop. 
Park Res., 76, 1896. 
[Mr. F. F. Forbes has found in moist land at W. Roxbury a speci- 
men which he pronounces the above hybrid re-crossed with S. discolor, 
also a specimen re-crossed with S. humilis.| 
S. discolor Muhl. X rostrata Richards. Wet ground near Ham- 
mond's Pond, Newton (F. F. Forbes, May 12 and Aug. 18, 1908); 
W. Roxbury (F. F. Forbes, May 10 and Aug. 10, 1908). 
S. humilis Marsh. X petiolaris Sm. Roadside, Boxford (F. F. 
Forbes, May 30, 1909). 
S. humilis Marsh. X rostrata Richards. Dry ground, Natick 
(F. F. Forbes, 1908). 
S. humilis Marsh. X sericea Marsh. Dry soil, Natick (F. F. 
Forbes, 1908). 
