3i6 
EDMUND W. SINNOTT 
single gap in the cylinder {jig. 22 and photo. 4). These three are the 
Nyssaceae, Alangiaceae and Rhizophoraceae, which are trilacunar. 
The first two have often been included under the Cornaceae, an afhnity 
which the structure of the node supports. Nodal anatomy also indi- 
cates that the Rhizophoraceae should not be placed in the Myrtiflorae 
which, aside from these three families, seems to be a natural order. 
Umbelliflorae 
The Umbelliflorae of Engler include the families Araliaceae, 
Umbelliferae and Cornaceae. As we have previously noted, the first 
two of these families are almost invariably characterized by an ampli- 
fied nodal structure, in which a large number of bundles, each leaving 
a separate gap, enter the base of the leaf {jig. 23 and Photo. 6). The 
Cornaceae, on the other hand, as far as has been observed are always 
trilacunar {Photo. 2) . The anatomy of the node thus supports evidence 
from other sources which goes to show that this family should not be 
included in the Umbelliflorae but should be placed elsewhere. The 
order thus reduced to the Araliaceae and the Umbelliferae seems to be 
a very natural one. 
Ericales 
The various families included under this order (Clethraceae, 
Pirolaceae, Ericaceae, Epacridaceae and Diapensiaceae) are all uni- 
lacunar {jig. 24) save the Epacridaceae, in which each of the sheathing 
leaves is supplied by a considerable number of separate strands. If 
the anatomy of the node is a sound criterion of relationship, the Epacri- 
daceae cannot be placed very close to the Ericaceae. This may well 
be an instance, however, where the structure of the flower is more de- 
pendable than that of the node. 
Primulales 
Members of all three families of this order are unilacunar. 
Plumbaginales 
The single family Plumbaginaceae included under this order 
appears to be entirely trilacunar. 
Ebenales 
The four families included under the Ebenales seem to be ex- 
clusively unilacunar {jig. 27). 
