BENEDICT: GENERA OF THE FERN TRIBE VITTARIEAE 159 
recognized, three show very simple venation patterns. Thus, 
Monogramma has either a single veinlet in the leaf or at most 
one, two, or three divisions of the trace forming as many areolae. 
In Hecistopteris the venation consists of a few free veinlets formed 
by the dichotomy of a single bundle at the base of the leaf. In 
Vittaria the venation consists of a midvein with a single row of 
simple areolae along each side. The number of the areolae in 
each row may be as few as one, or there may be very many, but 
the pattern is always simple. 
In the other four genera, Anetium, Ananthacorus, Antrophyum, 
and Polytaenium, as here described, there are always more than 
two rows of areolae across the leaf, so that the name “‘pluriseriate”’ 
may be applied to this type of venation. For want of a better 
term the three genera named in the preceding paragraph may 
be designated the ‘“‘simpler genera.” 
The generic characters may be briefly contrasted as in the 
following taxonomic key: 
Hecistopteris. 
tN 
Veins free-forking. 
Veins, if more than one, anastomosing to form simple areolae. 
Sporangia in a single marginal or dorsal line. 1. Monogramma. 
Sporangia in two or more lines or in small groups. 
Venation consisting of a midvein with a row of areolae 
i Viltaria. 
w 
along each side. 
Venation of more than two rows of areolae across the leaf. 
A percurrent midvein present, the lateral veins 
smaller and secondary. 
Sporangia in two submarginal rows along the 
outermost veinlets. 5. Ananthacorus. 
Sporangia usually in more than two lines, but 
never only on the outermost veinlets. 4. Polytaenium. 
Sporangia usually in small groups or patches on 
the intra-areolar spaces. netium. 
No percurrent primary midvein. 7. Antrophyum. 
A. SIMPLER GENERA 
1. MONOGRAMMA Schkuhr, Crypt. Gewiachse 1: 82. pl. 57. 
1809 
Type species, Pteris graminea Poir. Type specimen from the 
Bourbon Islands, Roemer. 3 
The genus Monogramma, properly delimited, that is, with the 
polypodioid American species excluded, includes five species, all 
