< r >58 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 Greene and 

 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 it 

 I am inclined to refer it to P. stamineum, to which also P. Langloisii 

 seems too closely related. 



The following new combinations give effect to conclusions 

 already stated. 



