558 ROBINSON: POLYCODIUM 
the New York Botanical Garden led to the conviction that Vac- 
cinium melanocarpum of Gray’s Manual is a good species, but 
that it is not identical with Mohr’s species but with his variety 
sericeum only. On all sheets in the New York herbarium the 
character of pubescence on the hypanthium, always more or less 
definitely present on fruit as well, was accompanied by another 
character. The calyx lobes were accrescent in late flower or early 
fruit. This was easily evident to the eye, but on measuring, the 
balance of difference proved slight, the fruiting calyx being 1.5-2 
mm. long in P. stamineum and 2.5-3 mm. long in the collections 
referable to sericeum. There was a single plant in which a glabrous 
hypanthium was accompanied by an accrescent calyx. This plant, 
on fine division, would be referred to P. candicans Small. 
Examination of material from the United States National 
Herbarium shows that the same is true of the collections there. 
But the specimen that Mohr seems to have considered as the type 
of his species has a glabrous hypanthium, and the calyx is not 
accrescent. So far, then, as Polycodium melanocarpum (C. Mohr) 
Small is concerned, there is room for difference of opinion; if the 
character of succulent fruit is considered sufficient, it may be 
maintained as a species, but no other sufficient reason has been 
found for holding it specifically distinct from P. stamineum. But 
the evidence is otherwise as regards V. melanocarpum sericeum. 
Typical forms of P. candicans (C. Mohr) Small differ notably 
from more typical P. stamineum in glaucescence, but the extremes 
are united by many intermediates, and no sharp line for separation 
has been found. Moreover, there is much reason for believing 
that this is a revival of P. elevatum Greene, the Vaccinium album 
of Pursh, although not the Linnaean species of the latter name, 
which does not belong to the family. 
Two species have not been discussed, P. oblongum G 
P. Langloisii Greene, of neither of which I have seen the types: 
Its author places the former in the P. floridanum group, but from 
the description and study of material which seems to match 
I am inclined to refer it to P. stamineum, to which also P. Langlois 
seems too closely related. 
The following new combinations give effect to © 
already stated. 
reene and 
nclusions 
