BOTANY OF TIIE NORTHERN UNITED STATES. Cl 



P. 573. 



(rather than Arena) CARYOPHYLLEA, L., resembling A. praecox,but 

 taller, and with a very diffuse panicle of purplish and at length silvery scarious 

 spikelets, was detected in abandoned fields reverting to forest, near Newcastle, 

 Delaware, by Wm. M. Canby. (Nat. from Eu.) 



P. 576. 



l a . Paspalunt Walteriaiium, Schult. Spikes few (3-7), the 

 lowest scarcely emerging from the sheath, the membranaceous rhachis blunt 

 and not projecting; spikelets glabrous. Delaware (E. Tatnall, Wm. M. Canby) 

 and southward, in very wet places. 



P. 586. 



5 a . Eqtlisetuttl palustre, L. Stems 6'- 18' high, much more slender 

 than those of no. 5, and with numerous branches, roughish, with only 5-9 broad 

 and deep grooves separated by prominent narrow ridges ; sheaths with as many 

 elongated lance-subulate teeth, pale. In wet places, Buffalo, New York (G. 

 W- Clinton), and northward. (Eu.) 



P. 592. 



3. Clieilanthcs lamigindsa, Nutt. in herb. Hook. Stalks slender, 

 at first hairy, black or brown, shining ; fronds (3' -8' high) delicate, lanceolate 

 in outline, woolly with soft whitish hairs, becoming smoother above, 3-pinnate ; 

 pinnae ovate, the lower ones distant ; pinnules crenately pinnatifid, or mostly 

 divided into minute roundish segments, the herbaceous margin recurved, forming 

 an almost continuous involucre. (C. vcstita, Hook, &c. C. gracilis, Metten.) 

 In dense tufts on dry rocks and cliffs, Wisconsin ( T. J. Hale), Iowa, and west- 

 ward. Ultimate pinnules exceedingly small and crowded. 



606. 3. MARSILEA, L. 



Submersed or emersed aquatic plants, with slender creeping rootstocks, send- 

 ing up elongated petioles, which bear at their apex a whorl of 4 nervose-veined 

 leaflets, and at or near their base, or sometimes on the rootstock, one or more 

 globular but somewhat excentric sporocarps. These sporocarps or fruit are 2- 

 cclled vertically, and with many transverse partitions, and split or burst into 2 

 lobes at maturity. On the partitions are inserted numerous short-stalked spo- 

 rangia, of two sorts intermixed ; the larger ones containing a single oval or ob- 

 long spore, the smaller containing many very minute spores. 



1. ITI. qiiadrifoBia, L. Leaflets broadly obovate-cuneate, glabrous; spo- 

 rocarps usually 2 or 3 on a short peduncle from near the base of the petioles, 

 pedicelled, glabrous or somewhat hairy. In water, the leaflets commonly float- 

 ing on the suiface, Bantam Lake, Litchfield, Connecticut, Dr. T. F. Allen. The 

 only known habitat in America ! (Eu.) 



2. ITI. vestita, Hook and Grev., with hairy leaflets and villous short-stalked 

 or sessile sporocarps, will doubtless be found in the western part of Wisconsin. 



