A flora of Manila - Rainforestation

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A FLORA OF MANILA
a longitudinal, incomplete annulus, interrupted by the stalk, opening trans-
versely. Indusium present or absent.
Genera about 120, species nearly 5,000, in all parts of the world, 81
genera and about 700 species in the Philippines.
1. Sori densely covering the entire back of the frond, or parts of the frond.
2. Fronds pinnate; very coarse terrestrial ferns of brackish swamps, the
sporangia not gathered into sori 16. Acrostichum
2. Fronds simple, entire; epiphytic ferns from creeping rootstock the
sporangia in contiguous sori 14. Cyclophorus
2. Fronds finely 3- or 4-pinnately divided, the ultimate segments small,
the fertile ones golden-yellow on the lower surface, the indusium
consisting of the reflexed margins of the segments 10. Onychium
1. Sori definite, on the" back of the frond, scattered, or in regular rows,
not strictly marginal.
2. Fronds entire, dimorphous, the sori reticulate, following the nerves
over the entire lower surface 6. Hemionitis
2. Fronds pinnately lobed, pinnate, or decompound.
3. Sori round or nearly so.
4. Indusium present.
5. Pinnae articulated to the rachis 2. Nephrolepis
5. Pinnae not articulated to the rachis 1. Dryopteris
4. Indusium none.
5. Fronds all alike 13. Polypodium
5. Fronds dimorphous ; basal, sterile, concave, humus-gathering ones
which are at first green, soon becoming brown, and ordinary
green, pinnately lobed fertile fronds 15. Drynaria
3. Sori elongated.
4. Indusium wanting; finely pinnately compound ferns, the lower
surface covered with white waxy powder 7. Ceropteris
4. Indusium present.
5. Veins forming regular areolae, or if not then the sori often
double, on both sides of the veinlets 4. Athyrium
5. Veins not forming regular areolae, except sometimes at the
margin, the sori always simple 5. Asplenium
1. Sori marginal, definite.
2. Indusium half cup-shaped, attached by the base and margins, opening
outward 3. Davallia
2. Indusium formed of the reflexed modified or unmodified margin of the
frond.
3. Sori borne on the inner face of the reflexed leaf-margin.
11. Adiantum
3. Sori not on the inner surface of the reflexed-margin, protected by
it, but borne on the frond itself.
4. Sori linear, on a .strand connecting the tips of the veins, the
reflexed margin of the leaf continuous; usually coarse, not
finely divided ferns 12. Pteris
4, Sori terminal on the veins, at first distinct, later confluent, the
i-eflexed margin pf the leaf interrupted; slender, finely divided
ferns 9. Cheilanthes
2. Indusium none; otherwise very similar to Cheilanthes.... 8. Notholaena