162 BENEDICT: GENERA OF THE FERN TRIBE VITTARIEAE 
The generic separation of Monogramma, as compared with the 
simpler species of Vittaria, depends on the simplicity of the 
venation and the simple sporangial line. In M. graminea, M. 
trichoidea, and M. dareicarpa, the line is lateral, as shown in the 
plate. In the other two species it is dorsal, but even in the 
two-areolate leaves of M. paradoxa, the two grooves open together 
along the midvein and at maturity form but a single line of 
sporangia. But between this type and the type characteristic of 
Vittaria there is really no very wide “‘generic”’ distinction. 
2. HECISTOPTERIS J. Smith, London Jour. Bot. 1: 193. 
1842 
Type species, Grammitis pumila A. Spreng. Syst. Suppl. 31. ° 
1828. (Type locality, ‘Ad corticem arborum, in Surinam. 
—Weigelt.”’) 
Hecistopteris is commonly recognized as including a single 
epiphytic species, H. pumila (A. Spreng.) J. Sm., native in northern 
South America. Excluding the simple-veined species of Mono- 
gramma, Hecistopteris pumila is the only free-veined species in 
the whole tribe of the Vittarieae. It is, like Monogramma, of 
particular morphological interest because of the very primitive 
character of its venation, both as compared with the more highly 
developed genera of the Vittarieae and as regards ferns in general. 
Probably all ferns in whatsoever family, Monogramma alone 
excepted, exhibit in their very early ontogeny a stage of develop- 
ment in which their venation corresponds to the type characteristic 
of mature Hecistopteris. 
As noted above, only one species is commonly recognized. 
Dr. Christ has given subspecific names to three variant forms 
but without urging their recognition as species. The original 
figure shows plants similar to that illustrated in FIG. 12-16 of 
PLATE 4. Fic. 1-8 and 19-22 of the same plate are taken from 
plants of two Bolivian collections and appear to represent a rather 
distinctive development, approaching in some respects to the 
outline and venation of the larger species of Monogramma. Such 
a form is perhaps worthy of further study with a view to deter- 
mine whether the form differences are not correlated with distinc- 
tive distribution. 
