FERNS AND FERN-AERIES 
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2. Spore-bearing shoot brown, soon withering i. B. arvense 
2. Spore-bearing shoot developing whorls of green branches 
2. B. sylvaticum 
3. Shoots scattered about, 3-7 mm. thick 3. B. laevigatum 
3. Shoots clustered, 5-12 mm. thick, 1 m. tall 4. B. hyemale 
1. E. arvense Field E. Common horsetail 
Spore-bearing shoots l-3dm. tall, light brown, juicy, withering, 
preceding the much branched green shoots, which become 2-3dm. 
tall. 
Cone 2-5cm. long, narrowly ellipsoidal ; sheaths of stem loose, 
8-12 toothed. Branches of green shoot 3-4-angled, whorled, rough, 
easily breaking at the nodes. Rhizomes long and slender, black, 
with frequent globular bulbs. 
Moist ground, common 
Railway on campus ; Botanic Garden. 
General over northern Eurasia and America 
April 
2. E. sylvaticum Woodland E. 
Cone-bearing shoot at first branchless, later developing whorls 
of slender drooping green branchlets ; l-3dm. tall, slender and 
delicate. 
Ridges of stem 8-14 ; branches 3-5-angled. Sheaths loose, with 
several rusty-colored teeth. 
Moist thickets, very rare here. 
Richland Twp. Jasper Co. (locality destroyed) ; Eldora? 
Entire north temperate zone north of 40 degrees. 
May- June 
3. E. laevigatum • Snake grass 
Shoots all alike, dark green, 4-8dm. tall, stiff and harsh, 3-5mm. 
thick, unbranched or with a few slender erect branches, often 
ending in a hard cone l-2cm. long. 
Evergreen. Sheaths green, with narrow black edge, the teeth 
soon falling off. Spreading by running rhizomes. 
Prairie banks, common 
North track ; Arbor Lake 
Ohio to B. C. and Tex. 
June, July 
4. E. hyemale Winter E. Scouring rush 
As above, except stems 5-10mm. thick, 6-12dm. tall; tufted in 
dense sods to the exclusion of everything else. 
Evergreen. Sheaths with 2 black rings separated by an ashy 
ring. Cones rarely seen. 
