M 



St. Louis River in Eastern Minnesota. From our common /^. Z>ry- 

 opteris it differs in having a glandular stalk and fronds, the latter 

 more erect and rigid, and having smaller pinnae on the lower side of 

 its primary divisions. An account of it will be found on page 277 

 of the ^* Additions and Corrections " of the " Ferns of North Amer- 



ica — Aspidiu?n conterininuiii and Notholaena Grayi were received 



just in time to be mentioned in that work, but N, nivea, and N. Lem- 



W(?/// have only come to hand when the last pages of the book are 

 already printed. 



D. C. Eaton. 



New Haven, June 21, 1880. 



Y % 46. Wolffia (Woimella) gladtata, Hegelm, {die Lemnaceen, 



/ eine y^ionographische Untersiichung] 1868, p. 133, Taf. Ill, fig. 24) 



• var. Floridana. — Frons lineari-falcata, in apicem flagelliformem 



attenuata, 15-20-plo longior quam latior, margine subintegra, per 



omnes partes fere ad apicem cavernosa, tota superficie cellulis pig- 



mentosis ochracec-punctata. 



Hab. Gainesville, Fla., Nov., 1877, H. W. Ravenel ; (specimens 

 in Herb. Harvard University from Dr. Geo. Engelmann under the 

 name of W.gladiata, Hegelm.)— Great Gulf Hammock, Levy Co,, 

 Fla., growing in extensive and thick mats on or near the surface of 

 stagnant water with Lemna minor, L., March, 1878, C. F. Austin and 

 J. D. S. — Exsiccated swampy ground, Sumter Co., Fla., adhering to 

 Hiccia nutans, L., var. terrestris, March, 1879, J. D. S. — Borders, 

 exposed by the subsiding water, of a pool near Ocala, Fla., with 

 Wolffia Cohwibiana, Karsten, Lemna polyrrhiza, L., Z. /;//>2.^;-, L., and 

 Amblystegiunt ripariiim, Br. & Sch„ April, 1879, J. D. S. — Very 

 abundant over marshes of Typha latifolia, L., four miles east from 

 Cedar Keys, Fla., March, 1880, J. D. S. 



Matured fronds are 3'' to 4" long, diminishing in breadth from 

 0.2" near the base to 0.04" at the apex. The base is arcuately 

 truncate with the stipitate angle hastate. The stipe is articulated, 

 sub-persistent, and 0.35" long. The pouch {fovea, Taschengrube) is 

 elongated, acuminate, 0.6" long, and at its mouth 0.3" broad. The 

 apical portion only of the frond {\--^oi its length) is destitute of 

 air-cavities. ^ Usually 2, and sometimes 3 to 6, vegetative generations 

 cohere. It is readily distinguishable from any described Cis-Mexi- 

 can form of Wolffia by its elongation, but better by the character of 

 the sub-genus, viz: '* Wolffiella. Frons pone marginem lateralem 

 foveae baeilaris proliferae irondimaternae affixa, directione horizontal! 

 symrnetrica. Plantae tantum steriles notae." (Hegelm. Lemnaceaein 

 Martins' Flora Brasiliensis, fasc. LXXVI, 1878). 



In the plant from Mexico, described as W. gladiata, the air-cavi- 

 ties do not extend to the anterior f— ^ part of the frond or to the 

 portion forming the pouch ; the sabre-shaped frond is one-half 

 shorter m proportion to its breadth, and with a 4 to 5 times broader 

 rounded apex. 



DnHegelmaier writes as follo'.vs in regard to specimens of this 

 plant submitted to him for examination under the name of W Flor- 

 idana^ n. sp. ; • 



fci 'n 



rhe plants from all four stations belong strictly to the same 



