430 Trans. Acad. Sci. of St. Louis. 
April 23d and May 7th, thus proving that their time of | 
flowering also is intermediate. 
mo| »: es : A 
ga! ¢g ES a F Sis 
ow ° = -= = a ° =) oo 
Ba) 3/3|8 rey eee t dees &| & 
Mixed |S} 2/2] 6 e|;/ol/sa!i8ieig 3 
a) 2) 8) gaigisisis|sia Bel g 
orms. [2@3/SS)/ ale1Sisl2limalhlalel] els a 2 = 
Qe oe? . . °o 2S eo . cay bo Oo @O f= a) oa - s 
es Si S/SiSiS8 Si slal2eisisieis<i3) &§ 
SSX |alal|malalalalAloa|mal|al|alA ia [al 
( 5-2 
| 3} 6-9 
o x! >. a > x | 5-6/Sm.| x Fr 
} 1 
Sterile. { 5} 5-98 
9-17 ] Witiooe Tfois cea 6-8) © 
9} 4~26 
6-18 Se ee ee 6-9| Sc.| x 
(| 5 (6-1 he [Mit x x x x 
5-26 
Fertile. 8} 7-25 
[ 9-18| x! m.| s. Sy ed aw x os een ZS 
12 \6-17| x! 1 aS os eh 5 ee’ Case Wee ead r. | x |....|Sub-fr 
“aru. § iS -* 5 ay een ae mS x 1 ef el Ss | 
Sos Whee cents OR ee Lae pee] ok fev 
or fiower. (1 44 16-15) x! J xd vd xt xd. oe 
hort 
8, short; 1, long; m, medium; Sm, smooth; r, rough; Sc, scaly; !, exaggerates; 
Vv, moderate; fr, fragrant. 
The question arises, may there not be contamination from 
other species of Willows? I found no evidences of this, and 
am strongly of the opinion there is not. The only other na- 
tive species growing in this vicinity are S. cordata and S. 
longifolia ; and, very sparingly, S. humilis, and S. sericea, to 
none of which are nigra or amygdaloid closely allied. S. 
lucida from which the glandular character of amygdaloid might 
be thought to be derived does not grow here, and is extremely 
rare even as an ornamental tree. Contrary to descriptions in 
standard works S. amygdaloides is more frequently stipular 
and has larger stipules than S. nigra. The stipules being 
present mostly with vigorous shoots, holds true largely also 
in respect to 8S. nigra. , 
While the differences between the two under consideration 
are so striking there yet appears a remarkable closeness in 
their nature permitting them to hybridize so freely with each 
other. The plan of their venation is similar. I would be 
inclined to think that even those specimens of Amygdaloid 
