682 UNDERWOOD: FERNS OF THE PHILIPPINES 
quadripartite foliage characteristic of the genus. The species of 
Marsilea grow in wet places and often resemble in habit small 
plants of Orats. 
V. EQUISETALES 
This order of a single family has at present one known repre- 
sentative in the Philippines, Eguisetum debilis, also found in south- 
eastern Asia. 
VI. LYCOPODIALES 
All three of the families of this order are represented in the 
Philippines. They may be easily recognized as follows : 
I. Spores minute, of one sort. m 
Spores of two sorts, minute microspores and larger macrospores; leaves (in all 
Philippine species) 4-ranked, of two sizes. 3. SELAGINELLACEAE. 
2. Sporangia unilocular. 1. LYCOPODIACEAE. 
Sporangia 2-3-locular. 2. PSILOTACEAE. 
The Lycopodiaceae are represented by thirteen species of 
Lycopodium, two of which are said to be species of the temperate 
or subboreal region of the United States, a statement which ap- 
pears scarcely credible. 
The Psilotaceae are represented by Psilotum nudum with 
leaves reduced to mere rudiments, and trilocular sporangia, and 
Tmesipteris Tannensis with oval leaves nearly an inch long and 
bilocular sporangia. The Selaginellaceae are represented by 
thirty-three species of Se/aginella, the larger part of which have 
been added through the labors of Dr. Warburg. 
SUMMARY 
Orders Families Genera Species 
Ophioglossales I 4 “4 
Marattiales I 3 7 
Filicales 7 91 568 
Salviniales 2 2 2 
Equisetales I I I 
Lycopodiales 3 4 48 
Totals 15 105 633 
The fern flora of the Philippines is evidently related on the 
one hand to that of Formosa and the Asiatic continent, and on 
the other to that of the more southerly islands of Celebes and 
Borneo; the extensive recent additions to the fern flora of the 
