AN ENUMERATION OF CULTIVATED FERNS. 273 
venules free. Fertile segment a racliiform spike. Sporangia 
subglobose, sessile, in pedicellate crested whorls (rarely distinct), 
forming a clustered simple spike, opening vertically by a slit on 
the exterior side. 
1. H. Zeylanica, Hook. Gen. Fil. t. 47 JB ; Hook. 2nd Cent. 
Ferns, t. 94 ; Hook. Gard. Ferns, t. 28. Osmunda 
Zeylanica, Linn. Helminthostachys dulcis, Kaulf. 
— Ceylon, Malay, Molucca, Philippine, and other 
islands. 
157. BOTRYCHIUM, Linn. 
Fronds erect, with dissimilar sterile and fertile segments. 
Sterile segments foliaceous. deltoid, bi-tripinnatifidly decom- 
Genus 157.— Portion of barren and fertile segments, natural size; fertile 
enlarged. 
