,3 POLYPODIACEAE. 



12. Dryopteris spinuldsa (Retz) Kuntze. Spinulose Shield-fern. (Fig. 37.) 



Polytxxii urn sfiinulosum Retz. Fl. Scand. Ed. 2, 250. 1795. 

 ; t*t*iOos*m Sw. Schrad. Journ. Bot. 2: 38 1800. 

 .-frt's spinulosa Kuntze, Rev. Gen. PI. 813. 1891. 



Rootstock stout, chaffy. Stipes 6'-i8' long, bearing 

 a few pale brown deciduous scales ; leaves ovate-lan- 

 ceolate, 2-pinnate, the pinnae oblique to the rachis, 

 elongated-triangular, rather thin, the lower pairs 

 broadly triangular, slightly shorter than the middle 

 ones ; pinnules oblique to the midrib, connected by a 

 very narrow wing, oblong, incised or pinnatifid with 

 spinulose-toothed lobes ; indusium glabrous, orbicular- 

 reniform, fixed by its sinus. 



In rich woods, Newfoundland to Alaska and Washing- 

 ton, south to Kentucky and Michigan. Ascends to 5000 

 ft. in Virginia. Also in Europe and Asia. July-Aug. 



Dryopteris spinulosa intermedia ( Muhl. ) Underw. 

 Native Ferns, Ed. 4. 116 (1893). 



Aspidium intermedium Muhl. ; Willd. Sp. PI. 5: 262. 1810. 



Dryopteris intermedia A. Gray, Man. 630. 1848. 



Aspidium spinulosum var. intermedium D. C. Eaton in A. Gray, Man. EH. 5, 665. 1867. 



Scales of the stipes few, brown with a darker centre ; leaves oblong-oyate, 2-3-pinnate, the 

 pinnae oblong-lanceolate, spreading, the lowest unequally triangular-ovate ; pinnules crowded, pin- 

 nately divided ; indusium delicate, beset with stalked glands. Labrador to Alaska, south to North 

 Carolina and Missouri.(?) We have chosen this commonest American form for illustration. 



Dryopteris spinulosa dilatata vHoffm. ) Underw. Native Ferns, Ed. 4, 116. 1893. 

 Polypodium dilatalum Hoffm. Deutsch. Fl. 2: 7. 1795. 

 Aspidium spinulosum var. dilatation Hook. Brit. Fl. 444. 1830. 



pteris dilatata A. Gray, Man. 631. 1848. 



Scales of the stipe large, brown with a darker centre; leaves broadly ovate or triangular-ovate, 

 commonly 3-pinnate ; pinnules lanceolate -oblong, the lowest often much elongated ; indusium glab- 

 rous. Newfoundland to Washington and Alaska, south along the Alleghenies to North Carolina 

 and Tennessee and to Ohio and Nebraska. Also in Europe and Asia. 



13. Dryopteris Boottii (Tuckerm.) Underw. Boott's Shield-fern. (Fig. 38.) 



Aspidium Boottii Tuckerm. Hovey's Mag. 9: 145. 1843. 

 Aspidium spinulosum var. Boottii D. C. Eaton in A. 



Gray, Man. Ed. 5, 665. 1867. 

 Drvopteris Boottii Underw. Native Ferns, Ed. 4, 117. 



1893- 



Rootstock stout, ascending. Stipes 8'-i2 / long, 

 covered, at least below, with thin pale-brown 

 scales ; leaves elongated-oblong or elongated- 

 lanceolate in outline, thin, acuminate at the apex, 

 slightly narrowed at the base, nearly or quite 

 2-pinnate, i-2^ long, 3 / -5 / wide ; pinnae lanceo- 

 late, long-acuminate, broadest at the nearly sessile 

 base ; pinnules broadly oblong, very obtuse, the 

 lower pinnatifid ; sori distinct, borne about half 

 way between the midvein and margin ; indusium 

 orbicular-reniform, minutely glandular. 



In woods. Nova Scotia to Minnesota, south to south- 

 ern New York, Delaware and Maryland. Ascends to- 

 2000 ft. in Vermont. Also in northern Europe and 

 Asia. July-Sept. 



6. PHEGOPTERIS Fee, Gen. Fil. 242. 1850-52. 



Medium sized or small ferns with 2-3-pinnatifid or ternate leaves and small round sori borne 

 on the t>acks of the veins below the apex. Stipe not jointed with the rootstock. Indusium 

 none. Fertile (spore-bearing) and sterile leaves similar. Sporanges pedicelled, provided with 

 a vertical rin^, bursting transversely. [Greek, signifying Beech-fern.] 



nt i' species of wide geographic distribution. Besides the following another occurs in 

 western North America. 



leaves triangular, 2-pinnatifid ; pinnae sessile, adnate to the winged rachis. 



L*^ !>an broad, usually dark grt-t n i. p. Phegopteris. 



Leave* broad aa long, or broader, usually light green. 2. P. hexagonoptera. 



Leaves ternate, with the three divisions petioled ; rachis wingless. 3. P. Dryopteris. 



