POLYPODIACEAE (FERN FAMILY) 41 



short-stalked, rigid (1-6 dm. long) ; pinnae broadly lanceolate-scythe-shaped, 

 acute, the lowest short-triangular, strongly auricled on the upper side, spinulose- 

 dentate ; sori biseriate, at length saboonfluent. (Aspidium Sw.) — Rocky (calca- 

 reous) woods, Gulf of St. Lawrence ; and from Niagara Falls, Ont., to L. Superior, 

 westw. and northw. (Eu ) 



* * Fronds bipinnate. 



3. P. Braunii (Spenner) F^e. Fronds ovate- or oblong-lanceolate (4-9 dm. 

 long) tapei'ing to a veiy short-stiped base ; pinnules ovate or oblong, obtuse, 

 truncate and almost rectangular at base, short^stalked, or the upper confluent, 

 sharply toothed, beset with long and soft as well as chaffy hairs. {Aspidium 

 acnleatum, var. Doll.) — Rich, mostly upland woods, Nfd. to N. Y., and 

 L. Superior. (Eu.) 



14. ASPIDIUM Sw. Shield Fekn. Wood Fern 



Fronds tufted, 1-3-pinnate ; veins simple or branched. Sori orbicular, borne 

 on the back of the scarcely modified fertile frond. Indusium reniform or, if 

 orbicular, exhibiting a distinct narrow depression or sinus at one side, although 

 centrally attached. Stipes not articulated at the base. (Name from djiridiov, 

 a small shield, from the shape of the indusium.) Nephrodium Rich. 



«. Veins simple or once forlced ; fronds not evergreen ; stipes and slender 

 rootstocks nearly naked. 

 Lowest pinnae scarcely smaller than the middle ones. 



Fertile veins once forked . 1, A. Thelypteris. 



Fertile veins simple 2. A. simiilatwm. 



Lower pinnae gradually decreasing in size, the lowest very small . 3. A. novdioracenae, 

 ; Veins, at least the lowest, more than once forked ; fronds mostly ever- 

 gi-een ; stipes and rootstocks scaly 6. 

 6. Pinnae 40-6ti, small. 4-8 mm. broad .... . i. A. fragrant, 



b. Pinnae fewer, 12-90 mm. broad c. 

 e. Frond bipinnatifid or bipinnate (or sub-tripinnatiM near the base). 



Sori marginal ... . ....&. A, marginale. 



Sori not marginal. 

 Basal scales lance-linear, caudate-attenuate . . . . 6, A. Filix-mas. 



Basal scales ovate-oblong to deltoid. 

 Basal scales iirm, shining, dark chestnut-colored . . 7. j4. Goldianum. 

 Basal scales thin, dull, membranous, light brown. 

 Indusium glandular-puberulent. 

 Lobes of frond with incurved teeth; sori 3.5-1.8 mm. ' 



in diameter .... (9) ^. crifiiaium, var. CUnionianum, 



Lobes with spreading teeth ; sori 1-1.2 mm. in diameter. 8. A. BooUii. 

 Indusium glabrous. 

 Frond conspicuously narrowed at the base . . . 9. .4, crisiaium. 

 Frond scarcely or not at all narrowed at the base. 

 Lobes incurved-serrate. .(9) A. cristaium, yelv. ClinioTtdanum. 



Lobes spinulose-dentate 10. .4. spin/uloaum. 



V. Fronds tripinnate or tripinnatifld d. 

 d. Fronds tripinnatifid. 



Basal scales large, lance-oblong, darlc brown (10) A. spinulosnm, var. dilatatum. 

 Basal scales small, deltoid-ovate, light brown. 

 Indusium glandless . . . . . (10) A. spimilomm. 



Indusium glandular-puberulent . . (10) A. spinulosum, var. intermedium, 

 d. Fronds tripinnate . ■ (10) A. spinolusum, var. concordianum. 



V\. A. Thelypteris (L.) Sw. Fronds pinnate, lanceolate in outline; pinnae 

 horizontal or slightly recurved, linear-lanceolate, deeply pinnatifid ; lobes 

 oblong, entire, obtuse or appearing acute when in fruit from the strongly revo- 

 lute margins ; veins forked, bearing the (numerous and soon confluent) fruit 

 dots near their middle ; indusium minute, smooth and naked. {Nephrodium 

 Strempel ; Dryopteris Gray.) — Marshes; common. Aug. (Cosmop.) Forma 

 PcFFEBAE (A. A. Eaton) Robinson is a form with phinae variously forked 

 at the tip. 



2. A. simuiatum Davenp. In habit similar to the preceding; veins simple; 

 fruit dots few (-3-10 on each lobe) ; indusium glandular-oiliolate. {Dryopterin 

 Davenp.) — Boggy woods, etc.. Me. to Vt. and Md. ; reported from Mo. 

 1/3. A. noveborac6nse (L.) Sw. Fronds pinnate, -lanceolate in outliue, toper- 

 (ng both ways from the middle ; pinnae lanceolate, the lowest 2 or more pairs 



