GENERA AND SPECIES. I3I 
Pisve LL 
OSMUNDA. Linnzus. 
GEN. CHAR.—Sporangia globular, short-stalked, destitute of an 
indusium, clustered on the margin of the much-contracted fertile 
frond, or portion of frond. 
This is the typical genus of the sub-order Osmundacee, 
and its characteristics are quite distinct. Figure 1 repre- 
sents a portion of a fertile frond slightly magnified; figure 
2, sporangia and spores greatly magnified, the globular 
sporangia with two valves opening from the top. The fer- 
tile part of the frond is very much contracted, the pin- 
nules being sometimes broad and foliate on one side, and 
narrow, with fruit-capsules, on the other. 
This genus has three representatives in this country, all 
found in Kentucky. They are tall stately plants, growing 
usually in low, wet grounds in the neighborhood of swamps 
and marshes. The fertile fronds, with their clusters of 
ferruginous sporangia, amid the masses of green foliage, 
serve to make them exceedingly picturesque. A fossil 
species is described from the Tertiary of the Western Ter- 
ritories.* * 
*See Lesquereux’s Tertiary Flora, p. 60, pl. iv, fig. I. 
