1922] 



PFEIFFER MONOGRAPH OF THE ISOETACEAE 113 



7. I. Malinverniana Cesat. & De Not. Ind. Sem. Hort. Reg. 

 Bot. Genuensis, 1858; Ann. Sci. Nat. Bot. 4: 381. 1859; Linnaea 

 30: 741. 1859-60; Baker, Jour. Bot. 18: 106. 1880; Motel. & 

 Vendr. Actes Soc. Linn. Bord. 36 : 342. 1883. 



Calamaria Malinverniana Kuntze, Rev. Gen. PL 2: 828. 1891- 

 93. 



Corm 3-lobed; leaves 90-100, 30-80 cm. long, rich 1 green, 

 prismatic, subulate, with narrow membranous margin little ex- 

 tended (0.5-1.0 cm.) above level of sporangium; stomata few; 

 peripheral strands 6; ligule lanceolate; sporangia oblong, 2-2.5 

 cm. long; velum none; megaspores white when dry, ashy when 

 wet, 660-800 \\ in diameter, with long coarse processes (sometimes 

 80 p in length), rounded at tip, extending on all faces between 

 narrow commissural ridges wavy in outline, frequently with large 

 compound knob occurring on upper face in angle formed by 

 ridges; microspores 33-38 \\ (rarely 29 n) in length, spiny. 



Distribution: Piedmont, in Italy. 

 Specimens examined: 



Italy: in slow-flowing water in aqueducts, "Greggio and Olden- 

 ico," Piedmont, fruiting all summer, through the fall, even 

 into winter, 1865, Cesati (Mo. Bot. Gard. Herb, and N. Y. 

 Bot. Gard. Herb.) ; near Oldenico, Piedmont, 3 May, 1863, 

 Ascherson (Mo. Bot. Gard. Herb., N. Y. Bot. Gard. Herb., 

 and Gray Herb.) ; ditches about Vercelli, "note de Durieu 

 dans son herbier: recu vivant de M. Malinverni, le 25 Oc- 

 tobre, 1867," Malinverni (Mo. Bot. Gard. Herb.) ; Piedmont, 

 prov. Novara, in fountains and aqueducts, submersed, float- 

 ing, throughout year, 1910, (Gola) Fiori & Beguinot 1606 

 (Gray Herb.); near Oldenico, Piedmont, 1859, Malinverni, 

 (N. Y. Bot. Gard. Herb.). 



This species is the giant form of Europe in leaf number and 

 length. The size of its megaspores is equalled only by that of 

 /. Duriaei Bory, which, however, in other features is a much 

 smaller plant. The coarse, long processes, visible to the naked 

 eye, and the peculiar large grains, compounded as it were from 

 a number of warty prominences, are definitely characteristic of 

 this species. 



8. I. cubana Engelm. Trans. St. Louis Acad. Sci. 4: 389. 

 1882; Sauvalle, Fl. Cub. 203. 1873, name only; Baker, Jour. Bot. 



