UNDERWOOD: FERNS OF THE PHILIPPINES 673 
4. Sori elongate-linear. 5- 
Sori round or oval. 7: 
5. Sori sunken in grooves. 3. Vittarieae. 
Sori superficial. 6. 
6. Indusium normally present (wanting in Coniogramme and Hemionitis). 
6. Asplenieae. 
Indusium wanting. Certain anomalous Po/yfodieae. 
7. Leaves and primary venation fan-shaped ; secondary venation anastomosing ; in- 
dusium wanting. 7. Dipterideae.* 
Leaves and venation normally pinnate. 8. 
8. Indusium superior or wanting. 9. 
Indusium inferior, rupturing above the sorus. 10. Woodsteae. 
Indusium attached internally, opening toward the leaf-margin (wanting in J/ona- 
chosorum), Il. Davaltlieae. 
9. Leafstalks jointed at their attachment with the rootstock, leaving definite scars 
when they separate. 10. 
Leafstalks continuous with the rootstock ; sori dorsal or terminal on the veins, 
normally indusiate. 8. Dryopterideae.t 
Io. Indusium wanting ; sori dorsal or terminal. 4. Polypodieae. 
Indusium present; sori near the base of the veins. 9. Oleandreae. 
Tribe 1. Alcicornieae 
This tribe is represented in the islands by two species of stag- 
horn fern (A/cicornium), characterized by the cordate basal sterile 
leaves, and the single species of Cheiropleuria, with linear sporo- 
phyls and two-lobed foliage. Both are epiphytic ferns. 
Tribe 2. Acrosticheae 
About five species of Elaphoglossum with simple free-veined 
leaves, and a single species of Acrostichum with pinnate leaves and 
anastomosing veins make up the known representation of this tribe 
in the Philippines. The dense masses of sporangia spread in a 
uniform layer over the leaves form a character easily recognized. 
* Dipteris i in Synopsis Filicum was lassi ki in the genus Polypodium, with which it 
has no near alliance, and in Die natiirlichen Pflanzenfamilien it is placed in the As- 
Pidieae, in which it finds an equally insecure resting place. It is a unique fern without 
near relations and we place it in a distinct tribe. 
{Since Aspidium as a generic name must be retired to the oblivion of synonymy, 
it is desirable that we have a tribal name which is derived from a typical or character- 
istic genus contained in it. We therefore substitute Dryoptertdeae for Aspidieae hereto- 
fore in use. 
