

SCO FERN FAMILY. 



§ 2. Stems annual, not living through the mnter, branched, at least the sterile ones. 



E. limbSum. Muddy edges of streams, rather common : stems all alike, 

 2° - 3° high, with many furrows, frniting in summer, and afterwards sending 

 out a few upright branches ; sheaths with 15-20 dark-colored acute teeth. 



E. arv6nse, Common Horse-tail. Moist sandy places, common N. : 

 fertile stems uubranched, with very conspicuous .sheaths, 4' - 8' high, appearing 

 in earliest spring and soon withering; sterile stems 8' -20' high, producing 

 many whorls of rather rigid slender and mostly simple 4-angled branches. 



E. sylvdtieum. Woodland H. Common N., along the edges , of moist 

 woods : fertile stems appearing in early spring, but lasting all summer, both 

 these and the sterile ones producing many whorls of spreading or gracefully 

 decnrved compound softish .3 - 5-furrowed branches and branchlets ; sheaths of 

 the main stem loose, 8 - 14-toothed. 



132, FILICES, FERN FAMILY. 



Flowerless plants with creeping or ascending rootstocks . or even 

 erect trunks, bearing distinct leaves C fronds) , which are rolled up 

 (circinat e) in the bud (except in one gi-oup), and bear commonly on 

 tne under surface or on the edges the simple fructification, consist- 

 ing of l-celled spore-cases (technically called sporangia) variously 

 grouped in dots, lines, or masse.s, and containing but one kind of 

 minute, l-celled, powdery, numerous spores. A large family, most 

 abundant in warm and moist regions, consisting of 8 suborders, 6 of 

 whieh are represented with u?. 



[The divisions of a pinnatifid frond are jyroperly called segments ;.of a mmtate 

 f'ond, ]nnncE ; of a ^ — A-A-ninnnte frond, pinnuhs or uiiimaie setiments. 'ihe^alk 

 of the frond is a stipe ; its continuation 1hi mgh the frond, the rhiichis ; its branches, 

 partial or secmdofy^ rliachises. A rhachis bordered by the kafy portion becomes a 

 midrib, which may beprmary, secondary, ^c] j 



I. POLYPODIACE^, or TRUE FERNS : characterized by 

 stalked spore-cases, having a vertical, incomplete, many-jointed, 

 elastic ring, which straightens at matuiity, breaking open the spore- 

 case transversely, and so discharging the spores. Spore-cases rarely 

 if ever on very narrow thread-like branches ; the fruit-dots often 

 covered by a scale-like involucre (the indusium ). 



§ 1. No definite fruit-clots, but ike ^ore-crises in large patches on the imder surface 

 of the fertile frond, or entirely covering the under surface: no indudiim. 



1. ACEOSTICHUM § CHEYSODIUM. Fronds simple or pinnately branched, 



with reticulated veins : spore-cases covering the whole under surface of the 

 frond or of its upper divisions. 



2. PLATYCERIUM. Fronds irregularly forking; veins reticulated: spore-cases 



in large patches on special portions of the under surface. 



§ 2. Spore-cnses on ilie bach of the frond, sojnetimes near the margin, in dots or lines 

 (soi-i) placed on the veins or at the ends of the veins, but without indusium of 

 any kind. 



8. POLYPODIUM. Fronds simple or pinnate, rarely twice pinnate; veins free 

 or reticulated; fruit-dots round or roundish, at the ends of the veins, or at the 

 point where several veins meet (anastomose). Stalk articulated to the root- 

 stock, and leaving a distinct sear when decayed away. 

 14. PHEGOPTICKIS. Agrees with Polypodium iii most respects ; but has the fniit- 

 dots smaller, and commonly on the veins, not at their ends, and the stalk is 

 not articulated to the rhachis. 



i. GYMNOGRAMME § CEROPTERIS. Fronds compound, covered beneath 

 with white or yellow waxy powder: fruit-dots in long often forking linos 

 on the veins. 



