Saliz Nigra and Salix Amygdaloides. 429 
more prominent and persistent differences, though yet other 
characters may be quite as important, for example, the period 
of blossoming, or the difference in veining. When stipules 
are present I venture to assert if they are pointed, or if not 
glandular, the specimen under investigation cannot be S. 
Amygdaloides ; and, on the other hand, if glandular, it can 
not be pure S. nigra. The several types of leaves, stipules 
and fruits of each of the two species are illustrated on the 
accompanying plate. 
The following summary taken from my record will 
show at a glance the differences between nigra and amyg- 
daloides : — 
are 
5 : 513 lSe o| o 
Sixsclio;|;sise * fee 
oo P| oO} 6] i) o . S| 2 
Sg] 4 BE} | 8 leziss2s| sles . 5| & 
AolA|n & iSe og o8| 2/82} a j24) 2 
esi/2|2/38/5 [S8/esie® & (ass isi; ° 
S2iglels| & [ssiseiss! 3 |43] 2 [Sa] $s 
Se/2/2/2/4 Seals] 2 ies| 8 fal = 
Pir) wt — ° > 
PS gio Ce eed S| a 
m ic 2 
| 
PRURV Es NOR OMIO: oy, um ates 15 ee +e | 15 
“sterile A) SOS joao St 2}, 6 a a ie oy 
. no fruit or flower ..... 15 |} 16] 91] 31 | 40 
2) | een 66 | 28 16 | 48| 2| 6| 2 66] 9| 4 
Nigra fertile 17 6 EE eee ee he ie 
“sterile 14) .2-44 BCL S6 VB ae a i ete FAT 
“no fruit or flower........ 16°) 6 1 86. | BE Ts B etc 
Total a 18 | 14 18 | 8] 5 | 3/1139] 2] 6| 7/1 
|| 3 Not Recorded. 1 Slight. 
The following table embracing specimens of mixed forms 
selected from my list may prove interesting as showing the 
variations in hybidrization, as well as my method of recording. 
In the columns headed amygdaloid and nigra, an attempt was 
made to classify the specimens with that species to which they 
appear to come the nearest. While my data show that of pure 
amygdaloides 73 per cent blossomed from April 15th to 25th, 
and of pure nigra, all of the 14 sterile specimens after May 
3d, the 9 specimens of mixed sterile were collected between 
