The American Midland Naturalist 
PUBLISHED BI-MONTHLY BY TH UNIVRSITY 
OF NOTRE DAME, NOTRE DAME, INDIANA. 
VOL. IV. SEPTEMBER, 1rog15. NO. 5. 
SAMBUCUS PUBENS var. XANTHOCARPA.” 
JUN 
BY JAMES J. LYNCH. ee ce 
Sting) 
The species Sambucus pubens was first recognized as distinct 
from the European Sambucus racemosa’? by Michaux, but Britton‘ 
identifies it with Sambucus racemosa of Europe. ‘The new variety 
xanthocarpa was found by Nieuwland (2) and showed sufficient 
differences from Sambucus pubens and Sambucus racemosa, and 
this will here be considered for study. 
HABIT OF THE SEEDLING. 
The young seedlings were grown indoors and seemed to. 
thrive easily under ordinary cultivation. The seeds are ovoid 
in shape, channelled and have minute transverse linear markings. 
In the germination of the seed the embryo breaks through the 
seed coat very close to the scars and primary root and hypocotyl 
emerge in succession. (lig. 1). The cotyledons are ovate to 
spatulate in shape ‘and the petiole is ridged longitudinally on 
its inner side. The primary root goes down to a length of about 
one and a half centimeters from a more or less prolonged hypocotyl 
and is covered by numerous root hairs. Upon further develop- 
ment of the epicotyl there appear two or three simple serrate 
leaves, broadly ovate to cordate. (Fig. 2.) The formation of 
stem and the increase of leaf development occurs in usual way 
of dicotyledons. (Fig. 13.) The later leaves, however, become 
more and more typically pinnate. The first are trifoliolate with 
small ovate side leaflets and a large apical one. Transition stages 
are found between simple and compound leaves. The simple 
- 1? Part of thesis offered as partial requirment for degree of B.S. in Biol. 
2-Tinnaeus, C., Species Plantarum, 270 (1753). 
3 Michaux, A., Flora Bor. Americana I. 181 (1803). 
4 Nieuwland, J. A.. Am. Mid. Nat. III., 310 (1914). 
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