18. I. D r u m m o n d i i A. Br. in Berl. Monatber. 1863, 593 ; 1868,
512. — Eootstock 3-lobed. Habit of European I. tenumima.
Leaves 6 -1 2 , scarcely diaplianous, 2 -3 in. long, J - J lin. diam.,
tapermg to the point, fiirnished with stomata, but without
accessory bast-bundles. Sporangia small, g lo b o se ; veil none.
Macrospores small, chalk-white, with numerous tubercles, whioh
are distinct between the grooves, but over the basal half confluent
into ridges.
Hab. Swan Eiver, West Australia, Drummond 989 !
Group 3.— Atvphihiai.
19. I. B u t l e e i Eugelm. in Amer. Bot. Gaz. iii. (1878), 1.—
Eootstock 2-lobcd. Habit of I. melanopoda; said to be dioicous.
Leaves 8 -1 2 , 3 -7 in. long, moderately firm in texture, tapering to
the point, furnished with stomata and accessory bast-bundles.
Sporangia globose or o b lo n g ; veil very narrow. Maorospores
larger than in melanopoda, marked with distinct or rarely confluent
tubercles. Microspores sqiinulose.
A , watershed between the Bed Eiver and
Arkansas Eiver, Western United States, G. D. Butler.
_ 20. I, m e l a n o p o d a j . Gay; Durieu in Bull. Bot. Soc. France,
XI. 1 0 2 .— Eootstock deeply 2-lobed. Leaves 1 5 -5 0 , i - 1 ft. long,
liu. diam. at the middle, moderately firm in texture, oqiaque,
tapermg to the point, furnished with stomata and a few accessory
bast-bundles, narrowed suddenly into the dilated base. Sporangia
globose or oblong, l-6 th to l-5 tli in. long, often bright chestnutbrown,
copiously d o tted ; veil very narrow. Maorospores small,
nearly or quite smooth beyond the ribs. Microspores spinulose.
Shallow ponds and damp prairies, Western United States, from
Illinois to Iowa and Texas.
21 I. E n g e l m a n n i a . Br. in Flora, 1846, 178.—Eootstock deeply
o - i a a ’ of ®fout I. lacustris. Leaves
2 O - 1 0 0 , often a foot long, 1 hn. diam. at middle, diaphanous, pale
green, tapermg to the point, furnished with accessory bast-bundles
aud copious stomata, the edge deourrent from the base, short and
narrow. Sporange large, pale, oblong, unspotted; veil very
narrow. Maorospores middle-sized, white, honeycombed all over.
Microspores smooth or nearly so.
Hab Ponds in the Northern United States from New England to Missouri.
Y a i.v a h d a Engelm., is a large variety, with 100—200 leaves, l i —2 ft. Ions a
broader veil, both kinds of spores smaller, and microspores spinulose.
22. I. N u t t a l l i i a . B r .; Engelm . in Amer. Nat. 1874, 215 1
opava Nuttall H e r b .!—Eootstock faintly 2-lobed. Leaves 2 0 -6 0
3 -6 in. long, i hn. diam. at the middle, moderately firm in texture,’
pale green, opaque, 3-angled on the back, tapering to the point,
with three accessory bast-bundles and numerous stomata, the edo-e
decurrent from the base, short and narrow. Sporange small, pafe,
oblong ; veil complete. Maorospores middle-sized, densely minutely
granulated. Microspores papillose.
p o d L ^ ' meadows and edge of ponds in Oregon. Habit of I. melano-
23. I. FLACCIDA S liu ttlew .; A. Br. in Flora, 1846, 178.— Eootstock
2-lobed. Habit of I . echinospora, but leaves much longer,
1 0 -3 5 , 1 -2 ft. loug, 4 - f diam. at the middle, diaphanous, light
green, tapering to the point, furnished with accessory bast-bmidles
and copious stomata, the edge decurrent from the base short and
narrow. Sporange small, pale, oblong, l-6 th to l-5 th in. lo n g ;
veil complete. Macrospores small, covered with papillas, whioh are
confluent into ridges. Microspores slightly papillose.
Hab. Florida, in deep water. First gathered by Eugel. I. Ghapmanni
Engelm. has stouter leaves, about I 4 ft. long, larger macrospores, with less
prominent tubercles and ridges, microspores smooth or slightly papillose.
24. I. M a e t i i A. Br. ; Kuhn in FI. Bras. i. 646, tab. 7 8 .—
Eootstock 2-lobed. Leaves numerous, very slender, flaccid, flexuose,
2 ft. loug, with a ferruginous edge at the base and biseriate
stomata iu the upper part. Sporange whitish ; veil in com plete;
tongue short, brown, cordate-triangular. Maorospores white,
rugose. Microspores quite glabrous.
Hab. Brazil; Minas Geraes, in a stream at Caldas, Begnell iii. 1506,
Mosen 2027.
25. I. SETACEA Boso Dlot. Hist. Nat. ; A. Br. in Verhand.
Branden, 1862, 30.—Eootstock 3-lobed, rarely 2-lobed. Leaves
1 0 -3 0 , often a foot long, 4 lin. diam. at middle, pale green,
opaque, moderately firm in texture, tapering to the point, furnished
with copious accessory bast-bundles and stomata, the base suddenly
dilated, its deourrent edge reaching up the lamina about 2 in.
Sporange pale, globose ; veil none ; tongue as long as the sporange.
Maorospores large, pure white, closely flnely tubercled all over.
Microspores cristate.
Hab. South of France, in ponds nearly dry in summer.
26. I. ADSPEBSA A. Br. Expl. Scient. Alg. tab. 87, fig. 3.— Eootstock
3-lobed. Habit of I . setacea. Leaves 1 2 -2 0 , 8 -9 in. long,
4 - 4 in. diam. at the middle, opaque, pale green, moderately firm in
texture, furnished with stomata and accessory bast-bundles, the
edge decurrent from the base short and narrow. Sporange small,
spotted, globose ; veil very narrow ; tongue twice as long as broad.
Maorospores with strong ribs and a few large tubercles. Micro-
spores prickly or crested.
Hab. Algeria and South France, in ponds dried up iu summer.
27. I. MALiNVBRNiANA Cesatl & De Not. Ind. Sem. Hort. Bot.
Genuen. 1858, 3.—Eootstock 3-lobed, reaching an inch in diam.
Habit of the large varieties of lacustris, but leaves muoh more
elongated, 2 0 -5 0 or more, a foot or more long, f - 1 lin. diam. at
the middle, diaphanous, bright green, tapering gradually to the
qioint, furnished with stomata and accessory bast-bundles, the
membranous edge deourrent from the base about 3 in. Sporange
large, pale, oblong; veil n on e ; lip as long as the short tongue.
Maorospores large, white, muricated all over. Microspores
smooth.
Hab. Aqueducts in Piedmont, Moris ! De Notaris !
K