thurium atropurpureum (Pl. XXII). Later studies may 
indicate that this species represents a very important 
complex on the Cretaceous quartzitic hills and savannahs 
of the Vaupés and Amazonas. 
Anthurium atropurpureum Schultes & Maguire 
‘ar. apertum 3 Schiultes var. nov. 
Haec varietas ab Anthurio atropurpureo nervis secun- 
dariis arcuatis apertis vel non confluentibus spatha spa- 
diceque majoribus differt. 
It might at first seem that the venation character upon 
which this newly described variety is based is trivial. Not- 
withstanding its rather unobtrusive nature on superficial 
examination, | have found that it is stable. Having no 
other morphological characters of importance to differen- 
tiate it as a species, this concept is probably best treated 
as a variety of Anthurium atropurpureum. 
The secondary veins of Anthurium atropurpureum, as 
‘an be seen in the figure published herewith, are arcuate 
and run together near the margin of the leaf-blades to 
form a continuous and stout nerve parallel to the margin. 
In the new varietal concept here described, the secondary 
veins are also arcuate, but they are not confluent and, 
consequently, do not form a continuous nerve along each 
margin. The varietal epithet has reference to the open 
appearance of the veins in contrast to the closed appear- 
ance which the confluent veins of the species exhibit. 
Like Anthurium atropurpureum, this new variety is 
an inhabitant of the curious xerophytic islands of savan- 
nah or scrubby vegetation that are found scattered here 
and there in the Colombian Amazonia. Anthurium atro- 
purpureum var. apertum is probably much more abun- 
dant and perhaps more widespread than is A. atropur- 
pureum itself. 
CoLombia: Comisarias del Amazonas-Vaupés, Rio Apaporis, Raudal 
de Jirijirimo. Extensive white-sand savannah or caatinga on right 
[ 180 | 
