—Si- 



distinguishing points which will be helpful to some be- 

 ginner. If your fern is lance-ovate in outline and twice 

 pinnatifid, the pinnae oblique to the rachis frequently 

 nearly forty-five degrees, with two or three of the lower 

 pairs broadly triangular, those above more elongated, the 

 pinnules also set oblique to the midrib and connected with 

 each other by a narrow wing rather coarsely serrate or 

 lobed each ending in a spinulose tooth the margin of the 

 indusium entire and smooth, you may safely call your 

 specimen A. spinulosum. It is generally found in moist, 

 shady woods in the Northern States. If your frond has 

 a longer and broader ovate outline and often thrice pin- 

 nate, the pinnae rather distant on the rachis, the lower 

 triangular but unequally so, pinnules crowded, more finely 

 toothed and lobed than above, the margin of the indusium 

 jagged and beset with very small stalked glands (to see 

 them plainly required a glass magnifying twenty or thirty 

 diameters; the sori that protrude from the edges of the 

 indusium must not be mistaken for the glands) , it is very 

 probable that your fern is the variety intermedium. It is 

 very common in damp woods. If your specimen frond is 

 broader at the base than either of the above approaching 

 triangular ovate and nearly always thrice pinnatifid, the 

 pinnules lance-oblong, the indusium entirely smooth and 

 naked, it is pretty certain you have found the variety 

 dilatatum. This form is not so frequently met with as 

 the two above and is generally found on mountains and 

 elevated ground. A. Boottii has elongated, lanceolate 

 fronds inclining to oblong in outline. It is thrice pin- 

 natifid, the pinnules broad-oblong, rounded on the ends, 

 somewhat pinnatifid below and serrated aibove. The 

 indusium is covered with minute glands which give it a 

 rough appearance under the microscope. It is a northern 

 fern and found about ponds and wet places. — James A. 

 Graves. (Reprinted from Linnaean Fern Bulletin Xo. 

 4. pages i, 2 and 3.) 



