52 CONTRIBUTIONS FROM THIS NATIONAL HERBARIUM. 



ANNOTATED LIST OF SPECIES. 



1. OPHIOGrLOSSACEAE. Adder's-toague Family. 



Sterile blade simple, entire, with netted veins; sporangia united in 2 rows in a simple 

 slender fleshy spike 1. OPHIOQLOSSUM. 



Sterile blade 1-3 times pinnately divided, with free veins; sporangia globose, all 

 distinct, borne in a 1-4-pinnate panicle 2. BOTRYCHIUM. 



1. OPHIOGLOSSUM L. Adder's-tongue. 



I. Ophioglossum vulgatum L. 



Low moist woods or partially shaded grassy slopes; numerous localities, but nowhere 

 abundant. June-July. Eastern N. Amer.; also in Eur. and Asia. 



2. BOTRYCHIUM Swartz. Grape fern. 



Sterile blade sessile, the common stalk nearly all above ground; leaf tissue very thin; 



spores maturing in June 1. B. virginianum. 



Sterile blade long-stalked,' the common stalk nearly all below ground; leaf tissue 

 much firmer; spores maturing in autumn. 

 Segments of the sterile blade mostly acute, the margins minutely toothed. 



2. B. obliquum. 

 Segments of the sterile blade less acute, deeply cut into slender spreading teeth. 



3. B. dissectum. 



1. Botrychium virginianum (L.) Swartz. Rattlesnake fern. 

 Woods; abundant; attaining its best development in rich hilly woods on the 



Virginia side of the upper Potomac. First of June. Widely distributed in N. Amer. 



2. Botrychium obliquum Muhl. 



Low brushy pastures amd moist thin woods; common. Aug.-Oct. Eastern N. 

 Amer, (B. ternatum obliquum D. C. Eaton.) 



3. Botrychium dissectum Spreng. 



Moist woods or thickets; common, but less so than B. obliquum. Aug.-Oct. Me. 

 to Va. and Ky. 

 Botrychium neglectum Wood has been reported, probably in error. 



2. OSMTJNDACEAE. Flowering fern Family. 



l. OSMUNDA L. 



Blades coarsely bipinnate, the large segments distant, sessile or short-stalked; apical 

 pinna? of some of the blades fertile, contracted, forming an upright terminal 



panicle 1. O. regalis. 



Sterile blades or parts of blades once pinnate, the pinnae pinnatifid into small close 



lobes. 



Blades normally of two kinds, wholly fertile or sterile, the former cinnamon-colored, 



succulent at maturity but quickly withering and disappearing; pinnae of 



sterile blade bearing a tuft of tomentum at base...... 2. O. cinnamomea. 



Blades either wholly sterile or with 2-6 pairs of middle pinna? fertile, these shrivel- 

 ing after maturity but persistent; sterile pinnae lacking tuft of tomentum at 

 b ase 3. O. claytoniana. 



1. Osmunda regalis L. Royal fern. 



Swamp borders and boggy woods; not uncommon. May^June. N. Amer. generally; 

 also in Eur. 



