40 POLYPODIACEAE (FERN FAMILY) 



pinnatijid, linear-lanceolate (7-13 cm. long) ; the lobes oblong, obtuse, reinutely 

 toothed, crowded, each bearing 8-6 pairs of oblong fruit dots^ some of tiien) 

 double. {A. thelypteroides Michx. ; Athyrium acrostichoides Diels.) — Rich 

 woods, N. S. to Ga., Ala., and Minn. ; not rare. (A.sia.) 



* * * Fronds hipinnate ; indusia at least in part reniform or horseshoe-shaped. 



11. A. Filix-femina (L.) Bernh. (Lady Ferx.) Fronds (4-10 dm. high) 

 ovate-oblong or broadly lanceolate, twice pinnate ; pinnae lanceolate, numerous : 

 pinnules confluent on the secondary rhachis by a narrow margin, oblong and 

 doubly serrate, or elongated and pinnately incised with cut-toothed segments ;. 

 fruit dots short, variously curved, at length confluent. {Athyrium Hoth.) — 

 Moist woods ; common and presenting many varying forms. July. (Cosmop.; 



11. SCOLOPENDRIUM Adans. Hart'sTongue 



Fruit dots linear, elongated, almost at right angles to the midrib, contiguous 

 by twos, one on the upper side of one veinlet, and the next on the lower side of 

 the next superior veinlet, thus appearing to have a double indusium opening 

 along the middle. (The ancient Greek name, employed because the numerous 

 parallel lines of fruit resen)ble the feet of the centipede, or Scolopendra.) 



1. S. vulgare Sm. Frond oblong-lanceolate from an auricled-heart-shaped 

 base, entire or wavy-margined (12-45 cm. long, 2-0 cm. broaa), bright green. 

 {Phyllitis Scolopendrium Newm.) — Shaded ravines and under limestone cliffs,- 

 Woodstock, N. B. ; Giey and Bruce Cos., Out. ; centr. N. Y. ; and Tenn. ; very 

 rare. Aug. (Mex., Eurasia.) 



12. CAMPTOSdRUS Link. Walking Leap 



Fruit dots oblong or linear, as in Asplenium^ but irregularly scattered on 

 either side of the reticulated veins of the simple frond, those next the midrib 

 single, the outer ones inclined to approximate in pairs (so that their two indusia 

 open face to face) or to become confluent at their ends, tluis forniing ci'ooked 

 lines (whence the name, from Kaixirrds, flexible, and o-wpos, for fruit dot). 



1. C. rhizophyllus (L.) Link. Fronds evergreen, subcoriaceous, growing in 

 tufts, spreading or procumbent (1-3 dm. long), gradually narrowed from a 

 cordate or auricled base to a long and slender acumination, which often roots at 

 the end and forms a new plant. — Shaded, especially calcareous rocks; centr. 

 Me. to Ottawa, thence to Minn., and south w. to Kan. and Ga. — The auricles 

 are sometimes greatly elongated, and even rooting ; in another form they are 

 lacking. 



13. POLYSTICHUM Roth 



Fronds tufted at the end of a stout rootstock, chiefly of firm or leathery 

 texture, evergreen ; stipes and rhachises chaffy. Sori orbicular, opening on all 

 sides of the circular peltate centrally attached indusium. (Name from ttoXiJ-, 

 many, and (xrixos, row, the sori of some species being in many ranks.) 



* Fronds narrowly oblong or lanceolate, simply pinnate, the pinnae sometimes 



again cleft. 



■»- Upper {spore-bearing') pinnae of the fertile fronds much contracted. 



1. P. acrostichoides (Michx.) Schott. (Christmas Fkrn.) Fronds 2-5 dm. 

 long, the scaly stipe 5-15 cm. in length ; pinnae linear-lanceolate, hnlf-halberd- 

 shaped at the slightly stalked base, serrulate with appressed bristly teeth; the 

 smaller upper pinnae bearing two rows of sori, which in age becoming confluent 

 cover their entire lower surface. {Aspidium Sw.) — Common in ro -ky woods 

 Var. ScHWEiNiTzii (Beck) Small {Aspidium acrostichoides, var. incisum Gray) 

 is a variable form with larger fronds, toothed or pinnatifid pinnae, the ft-rtile lesa 

 reduced and the sori less confluent, chiefly near the tips of the pinnae. — Not rare. 



-»- t- Upper (spore-bearing) pinnae similar to the others. 



2- P. Lonchitis (L.) Roth. (Holly Fern.) Fronds linear-lanceolate, ver^i 



