1914] Flora of the Boston District, — XIX 109 
S. humilis Marsh. X tristis Ait. Dry sandy soil, Natick (F. F. 
Forbes, 1908). . 
S. petiolaris Sm. X rostrata Richards. Swamp, Cow Island, 
W. Roxbury (F. F. Forbes, 1908). 
S. petiolaris Sm. X sericea Marsh. Swamp, Wayland (F. F. 
Forbes, 1912); wet ground, Sherborn (F. F. Forbes, May 21, 1907). 
S. petiolaris Sm. X subsericea (Anders.) Schneider. Cow 
Island, W. Roxbury (F. F. Forbes, 1909). 
S. petiolaris Sm. X tristis Ait. Dry sandy soil, Natick (F. F. 
Forbes, 1907). 
The older specimens listed above have all been passed upon by the 
late M. S. Bebb, our best American student of Salix. The hybrids 
found by Mr. Forbes have in most cases been transplanted by him 
to his willow garden, where they are still under his observation and 
may be seen by others. 
MYRICACEAE. 
MYRICA. 
M. asplenifolia L. Dry barren soil, very common throughout. 
M. carolinensis Mill. Dry sandy soil; very common along the 
coast, becoming less abundant inland. 
M. Gale L. Swamps, frequent throughout. 
JUGLANDACEAE. 
CARYA. 
C. alba (L.) K. Koch (not C. alba Nutt.). Dry open woods; com- 
mon in southern and central portions; reported as far north as Dan- 
vers and Essex. 
C. cordiformis (Wang. K. Koch. Dry soil, well distributed 
except in west and northwest, but seldom abundant. 
C. glabra (Mill.) Spach. Dry rocky soil; common. 
C. microcarpa Nutt. (in part). Waverley, Belmont ( B. L. Robin- 
son, June 2, 1895); Dorchester (W. Deane, Sept. 21, 1887). Mr. 
C. E. Faxon writes that there are specimens at the Arnold Arbo- 
retum, collected by himself, from Reading, Wellesley Hills, Lexing- 
